Revert r259619:

Fixes GCC libstdc++/29286

The fix seems to work for amd64 but causes segfaults on powerpc.
At this time gcc is much more important on powerpc than on amd64.

Reported by:	andreast

contrib/gcc/ChangeLog.gcc43

@@ -65,48 +65,6 @@
 	fvisibility-ms-compat.
 	* c.opt (fvisibility-ms-compat): New.
 
-2007-06-12  Ian Lance Taylor  <iant@google.com> (r125653)
-	    Daniel Berlin  <dberlin@dberlin.org>
-
-	PR libstdc++/29286
-	* tree.def: Add CHANGE_DYNAMIC_TYPE_EXPR.
-	* tree.h (CHANGE_DYNAMIC_TYPE_NEW_TYPE): Define.
-	(CHANGE_DYNAMIC_TYPE_LOCATION): Define.
-	(DECL_NO_TBAA_P): Define.
-	(struct tree_decl_common): Add no_tbaa_flag field.
-	* tree-ssa-structalias.c (struct variable_info): Add
-	no_tbaa_pruning field.
-	(new_var_info): Initialize no_tbaa_pruning field.
-	(unify_nodes): Copy no_tbaa_pruning field.
-	(find_func_aliases): Handle CHANGE_DYNAMIC_TYPE_EXPR.
-	(dump_solution_for_var): Print no_tbaa_pruning flag.
-	(set_uids_in_ptset): Add no_tbaa_pruning parameter.  Change all
-	callers.
-	(compute_tbaa_pruning): New static function.
-	(compute_points_to_sets): Remove CHANGE_DYNAMIC_TYPE_EXPR nodes.
-	Call compute_tbaa_pruning.
-	* tree-ssa-alias.c (may_alias_p): Test no_tbaa_flag for pointers.
-	* gimplify.c (gimplify_expr): Handle CHANGE_DYNAMIC_TYPE_EXPR.
-	* gimple-low.c (lower_stmt): Likewise.
-	* tree-gimple.c (is_gimple_stmt): Likewise.
-	* tree-ssa-operands.c (get_expr_operands): Likewise.
-	* tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Likewise.
-	* tree-inline.c (estimate_num_insns_1): Likewise.
-	(copy_result_decl_to_var): Likewise.
-	* expr.c (expand_expr_real_1): Likewise.
-	* tree-pretty-print.c (dump_generic_node): Likewise.
-	* tree-inline.c (copy_decl_to_var): Copy DECL_NO_TBAA_P flag.
-	* omp-low.c (omp_copy_decl_2): Likewise.
-	* print-tree.c (print_node): Print DECL_NO_TBAA_P flag.
-	* doc/c-tree.texi (Expression trees): Document
-	CHANGE_DYNAMIC_TYPE_EXPR.
-
-2007-06-09  Daniel Berlin  <dberlin@dberlin.org> (r125603)
-
-	* tree-ssa-structalias.c (set_uids_in_ptset): Add is_deref'd
-	parameter, use it.
-	(find_what_p_points_to): Pass new parameter to set_uids_in_ptset.
-
 2007-06-05  Joerg Wunsch  <j.gnu@uriah.heep.sax.de> (r125346)
 
 	PR preprocessor/23479

contrib/gcc/cp/ChangeLog.gcc43

@@ -25,12 +25,6 @@
 	* decl2.c (determine_visibility): Remove duplicate code for
 	handling type info.
 
-2007-06-12  Ian Lance Taylor  <iant@google.com> (r125653)
-
-	PR libstdc++/29286
-	* init.c (avoid_placement_new_aliasing): New static function.
-	(build_new_1): Call it.
-
 2007-05-31  Daniel Berlin  <dberlin@dberlin.org> (r125239)
 
 	* typeck.c (build_binary_op): Include types in error.

contrib/gcc/cp/init.c

@@ -1,7 +1,6 @@
 /* Handle initialization things in C++.
    Copyright (C) 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
+   1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
-   Free Software Foundation, Inc.
    Contributed by Michael Tiemann (tiemann@cygnus.com)
 
 This file is part of GCC.
@@ -1565,55 +1564,6 @@ build_raw_new_expr (tree placement, tree type, tree nelts, tree init,
   return new_expr;
 }
 
-/* Make sure that there are no aliasing issues with T, a placement new
-   expression applied to PLACEMENT, by recording the change in dynamic
-   type.  If placement new is inlined, as it is with libstdc++, and if
-   the type of the placement new differs from the type of the
-   placement location itself, then alias analysis may think it is OK
-   to interchange writes to the location from before the placement new
-   and from after the placement new.  We have to prevent type-based
-   alias analysis from applying.  PLACEMENT may be NULL, which means
-   that we couldn't capture it in a temporary variable, in which case
-   we use a memory clobber.  */
-
-static tree
-avoid_placement_new_aliasing (tree t, tree placement)
-{
-  tree type_change;
-
-  if (processing_template_decl)
-    return t;
-
-  /* If we are not using type based aliasing, we don't have to do
-     anything.  */
-  if (!flag_strict_aliasing)
-    return t;
-
-  /* If we have a pointer and a location, record the change in dynamic
-     type.  Otherwise we need a general memory clobber.  */
-  if (TREE_CODE (TREE_TYPE (t)) == POINTER_TYPE
-      && placement != NULL_TREE
-      && TREE_CODE (TREE_TYPE (placement)) == POINTER_TYPE)
-    type_change = build_stmt (CHANGE_DYNAMIC_TYPE_EXPR,
-			      TREE_TYPE (t),
-			      placement);
-  else
-    {
-      /* Build a memory clobber.  */
-      type_change = build_stmt (ASM_EXPR,
-				build_string (0, ""),
-				NULL_TREE,
-				NULL_TREE,
-				tree_cons (NULL_TREE,
-					   build_string (6, "memory"),
-					   NULL_TREE));
-
-      ASM_VOLATILE_P (type_change) = 1;
-    }
-
-  return build2 (COMPOUND_EXPR, TREE_TYPE (t), type_change, t);
-}
-
 /* Generate code for a new-expression, including calling the "operator
    new" function, initializing the object, and, if an exception occurs
    during construction, cleaning up.  The arguments are as for
@@ -1657,7 +1607,6 @@ build_new_1 (tree placement, tree type, tree nelts, tree init,
      beginning of the storage allocated for an array-new expression in
      order to store the number of elements.  */
   tree cookie_size = NULL_TREE;
-  tree placement_var;
   /* True if the function we are calling is a placement allocation
      function.  */
   bool placement_allocation_fn_p;
@@ -1751,20 +1700,6 @@ build_new_1 (tree placement, tree type, tree nelts, tree init,
 
   alloc_fn = NULL_TREE;
 
-  /* If PLACEMENT is a simple pointer type, then copy it into
-     PLACEMENT_VAR.  */
-  if (processing_template_decl
-      || placement == NULL_TREE
-      || TREE_CHAIN (placement) != NULL_TREE
-      || TREE_CODE (TREE_TYPE (TREE_VALUE (placement))) != POINTER_TYPE)
-    placement_var = NULL_TREE;
-  else
-    {
-      placement_var = get_temp_regvar (TREE_TYPE (TREE_VALUE (placement)),
-				       TREE_VALUE (placement));
-      placement = tree_cons (NULL_TREE, placement_var, NULL_TREE);
-    }
-
   /* Allocate the object.  */
   if (! placement && TYPE_FOR_JAVA (elt_type))
     {
@@ -1857,12 +1792,7 @@ build_new_1 (tree placement, tree type, tree nelts, tree init,
   /* In the simple case, we can stop now.  */
   pointer_type = build_pointer_type (type);
   if (!cookie_size && !is_initialized)
-    {
+    return build_nop (pointer_type, alloc_call);
-      rval = build_nop (pointer_type, alloc_call);
-      if (placement != NULL)
-	rval = avoid_placement_new_aliasing (rval, placement_var);
-      return rval;
-    }
 
   /* While we're working, use a pointer to the type we've actually
      allocated. Store the result of the call in a variable so that we
@@ -2121,9 +2051,6 @@ build_new_1 (tree placement, tree type, tree nelts, tree init,
   /* A new-expression is never an lvalue.  */
   gcc_assert (!lvalue_p (rval));
 
-  if (placement != NULL)
-    rval = avoid_placement_new_aliasing (rval, placement_var);
-
   return rval;
 }
 

contrib/gcc/doc/c-tree.texi

@@ -1916,7 +1916,6 @@ This macro returns the attributes on the type @var{type}.
 @tindex TARGET_EXPR
 @tindex AGGR_INIT_EXPR
 @tindex VA_ARG_EXPR
-@tindex CHANGE_DYNAMIC_TYPE_EXPR
 @tindex OMP_PARALLEL
 @tindex OMP_FOR
 @tindex OMP_SECTIONS
@@ -2573,13 +2572,6 @@ mechanism.  It represents expressions like @code{va_arg (ap, type)}.
 Its @code{TREE_TYPE} yields the tree representation for @code{type} and
 its sole argument yields the representation for @code{ap}.
 
-@item CHANGE_DYNAMIC_TYPE_EXPR
-Indicates the special aliasing required by C++ placement new.  It has
-two operands: a type and a location.  It means that the dynamic type
-of the location is changing to be the specified type.  The alias
-analysis code takes this into account when doing type based alias
-analysis.
-
 @item OMP_PARALLEL
 
 Represents @code{#pragma omp parallel [clause1 ... clauseN]}. It

contrib/gcc/expr.c

@@ -8718,13 +8718,6 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
       /* Lowered by gimplify.c.  */
       gcc_unreachable ();
 
-    case CHANGE_DYNAMIC_TYPE_EXPR:
-      /* This is ignored at the RTL level.  The tree level set
-	 DECL_POINTER_ALIAS_SET of any variable to be 0, which is
-	 overkill for the RTL layer but is all that we can
-	 represent.  */
-      return const0_rtx;
-
     case EXC_PTR_EXPR:
       return get_exception_pointer (cfun);
 

contrib/gcc/gimple-low.c

@@ -243,7 +243,6 @@ lower_stmt (tree_stmt_iterator *tsi, struct lower_data *data)
     case GOTO_EXPR:
     case LABEL_EXPR:
     case SWITCH_EXPR:
-    case CHANGE_DYNAMIC_TYPE_EXPR:
     case OMP_FOR:
     case OMP_SECTIONS:
     case OMP_SECTION:

contrib/gcc/gimplify.c

@@ -5748,11 +5748,6 @@ gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
 	  ret = GS_ALL_DONE;
 	  break;
 
-	case CHANGE_DYNAMIC_TYPE_EXPR:
-	  ret = gimplify_expr (&CHANGE_DYNAMIC_TYPE_LOCATION (*expr_p),
-			       pre_p, post_p, is_gimple_reg, fb_lvalue);
-	  break;
-
 	case OBJ_TYPE_REF:
 	  {
 	    enum gimplify_status r0, r1;

contrib/gcc/omp-low.c

@@ -518,7 +518,6 @@ omp_copy_decl_2 (tree var, tree name, tree type, omp_context *ctx)
 
   TREE_ADDRESSABLE (copy) = TREE_ADDRESSABLE (var);
   DECL_COMPLEX_GIMPLE_REG_P (copy) = DECL_COMPLEX_GIMPLE_REG_P (var);
-  DECL_NO_TBAA_P (copy) = DECL_NO_TBAA_P (var);
   DECL_ARTIFICIAL (copy) = DECL_ARTIFICIAL (var);
   DECL_IGNORED_P (copy) = DECL_IGNORED_P (var);
   TREE_USED (copy) = 1;

contrib/gcc/print-tree.c

@@ -402,8 +402,6 @@ print_node (FILE *file, const char *prefix, tree node, int indent)
 	    fputs (" virtual", file);
 	  if (DECL_PRESERVE_P (node))
 	    fputs (" preserve", file);	  
-	  if (DECL_NO_TBAA_P (node))
-	    fputs (" no-tbaa", file);
 	  if (DECL_LANG_FLAG_0 (node))
 	    fputs (" decl_0", file);
 	  if (DECL_LANG_FLAG_1 (node))

contrib/gcc/tree-gimple.c

@@ -1,6 +1,5 @@
 /* Functions to analyze and validate GIMPLE trees.
-   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007
+   Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
-   Free Software Foundation, Inc.
    Contributed by Diego Novillo <dnovillo@redhat.com>
    Rewritten by Jason Merrill <jason@redhat.com>
 
@@ -216,7 +215,6 @@ is_gimple_stmt (tree t)
     case TRY_FINALLY_EXPR:
     case EH_FILTER_EXPR:
     case CATCH_EXPR:
-    case CHANGE_DYNAMIC_TYPE_EXPR:
     case ASM_EXPR:
     case RESX_EXPR:
     case PHI_NODE:

contrib/gcc/tree-inline.c

@@ -1649,11 +1649,6 @@ estimate_num_insns_1 (tree *tp, int *walk_subtrees, void *data)
       *walk_subtrees = 0;
       return NULL;
 
-      /* CHANGE_DYNAMIC_TYPE_EXPR explicitly expands to nothing.  */
-    case CHANGE_DYNAMIC_TYPE_EXPR:
-      *walk_subtrees = 0;
-      return NULL;
-
     /* Try to estimate the cost of assignments.  We have three cases to
        deal with:
 	1) Simple assignments to registers;
@@ -2640,7 +2635,6 @@ copy_decl_to_var (tree decl, copy_body_data *id)
   TREE_READONLY (copy) = TREE_READONLY (decl);
   TREE_THIS_VOLATILE (copy) = TREE_THIS_VOLATILE (decl);
   DECL_COMPLEX_GIMPLE_REG_P (copy) = DECL_COMPLEX_GIMPLE_REG_P (decl);
-  DECL_NO_TBAA_P (copy) = DECL_NO_TBAA_P (decl);
 
   return copy_decl_for_dup_finish (id, decl, copy);
 }
@@ -2667,7 +2661,6 @@ copy_result_decl_to_var (tree decl, copy_body_data *id)
     {
       TREE_ADDRESSABLE (copy) = TREE_ADDRESSABLE (decl);
       DECL_COMPLEX_GIMPLE_REG_P (copy) = DECL_COMPLEX_GIMPLE_REG_P (decl);
-      DECL_NO_TBAA_P (copy) = DECL_NO_TBAA_P (decl);
     }
 
   return copy_decl_for_dup_finish (id, decl, copy);

contrib/gcc/tree-pretty-print.c

@@ -1443,17 +1443,6 @@ dump_generic_node (pretty_printer *buffer, tree node, int spc, int flags,
       is_expr = false;
       break;
 
-    case CHANGE_DYNAMIC_TYPE_EXPR:
-      pp_string (buffer, "<<<change_dynamic_type (");
-      dump_generic_node (buffer, CHANGE_DYNAMIC_TYPE_NEW_TYPE (node), spc + 2,
-			 flags, false);
-      pp_string (buffer, ") ");
-      dump_generic_node (buffer, CHANGE_DYNAMIC_TYPE_LOCATION (node), spc + 2,
-			 flags, false);
-      pp_string (buffer, ")>>>");
-      is_expr = false;
-      break;
-
     case LABEL_EXPR:
       op0 = TREE_OPERAND (node, 0);
       /* If this is for break or continue, don't bother printing it.  */

contrib/gcc/tree-ssa-alias.c

@@ -1,5 +1,5 @@
 /* Alias analysis for trees.
-   Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005 Free Software Foundation, Inc.
    Contributed by Diego Novillo <dnovillo@redhat.com>
 
 This file is part of GCC.
@@ -1961,29 +1961,28 @@ may_alias_p (tree ptr, HOST_WIDE_INT mem_alias_set,
 
   gcc_assert (TREE_CODE (mem) == SYMBOL_MEMORY_TAG);
 
-  if (!DECL_NO_TBAA_P (ptr))
+  alias_stats.tbaa_queries++;
+
+  /* If the alias sets don't conflict then MEM cannot alias VAR.  */
+  if (!alias_sets_conflict_p (mem_alias_set, var_alias_set))
     {
-      alias_stats.tbaa_queries++;
+      alias_stats.alias_noalias++;
+      alias_stats.tbaa_resolved++;
+      return false;
+    }
 
-      /* If the alias sets don't conflict then MEM cannot alias VAR.  */
+  /* If var is a record or union type, ptr cannot point into var
-      if (!alias_sets_conflict_p (mem_alias_set, var_alias_set))
+     unless there is some operation explicit address operation in the
-	{
+     program that can reference a field of the ptr's dereferenced
-	  alias_stats.alias_noalias++;
+     type.  This also assumes that the types of both var and ptr are
-	  alias_stats.tbaa_resolved++;
+     contained within the compilation unit, and that there is no fancy
-	  return false;
+     addressing arithmetic associated with any of the types
-	}
+     involved.  */
 
-      /* If VAR is a record or union type, PTR cannot point into VAR
+  if ((mem_alias_set != 0) && (var_alias_set != 0))
-	 unless there is some explicit address operation in the
+    {
-	 program that can reference a field of the type pointed-to by
+      tree ptr_type = TREE_TYPE (ptr);
-	 PTR.  This also assumes that the types of both VAR and PTR
+      tree var_type = TREE_TYPE (var);
-	 are contained within the compilation unit, and that there is
-	 no fancy addressing arithmetic associated with any of the
-	 types involved.  */
-      if (mem_alias_set != 0 && var_alias_set != 0)
-	{
-	  tree ptr_type = TREE_TYPE (ptr);
-	  tree var_type = TREE_TYPE (var);
       
       /* The star count is -1 if the type at the end of the pointer_to 
 	 chain is not a record or union type. */ 
@@ -1992,41 +1991,41 @@ may_alias_p (tree ptr, HOST_WIDE_INT mem_alias_set,
 	{
 	  int ptr_star_count = 0;
 	  
-	      /* ipa_type_escape_star_count_of_interesting_type is a
+	  /* Ipa_type_escape_star_count_of_interesting_type is a little to
-		 little too restrictive for the pointer type, need to
+	     restrictive for the pointer type, need to allow pointers to
-		 allow pointers to primitive types as long as those
+	     primitive types as long as those types cannot be pointers
-		 types cannot be pointers to everything.  */
+	     to everything.  */
-	      while (POINTER_TYPE_P (ptr_type))
+	  while (POINTER_TYPE_P (ptr_type))
-		{
+	    /* Strip the *'s off.  */ 
-		  /* Strip the *s off.  */ 
+	    {
-		  ptr_type = TREE_TYPE (ptr_type);
+	      ptr_type = TREE_TYPE (ptr_type);
-		  ptr_star_count++;
+	      ptr_star_count++;
-		}
+	    }
 	  
-	      /* There does not appear to be a better test to see if
+	  /* There does not appear to be a better test to see if the 
-		 the pointer type was one of the pointer to everything
+	     pointer type was one of the pointer to everything 
-		 types.  */
+	     types.  */
-	      if (ptr_star_count > 0)
+	  
+	  if (ptr_star_count > 0)
+	    {
+	      alias_stats.structnoaddress_queries++;
+	      if (ipa_type_escape_field_does_not_clobber_p (var_type, 
+							    TREE_TYPE (ptr))) 
 		{
-		  alias_stats.structnoaddress_queries++;
-		  if (ipa_type_escape_field_does_not_clobber_p (var_type, 
-								TREE_TYPE (ptr)))
-		    {
-		      alias_stats.structnoaddress_resolved++;
-		      alias_stats.alias_noalias++;
-		      return false;
-		    }
-		}
-	      else if (ptr_star_count == 0)
-		{
-		  /* If PTR_TYPE was not really a pointer to type, it cannot 
-		     alias.  */ 
-		  alias_stats.structnoaddress_queries++;
 		  alias_stats.structnoaddress_resolved++;
 		  alias_stats.alias_noalias++;
 		  return false;
 		}
 	    }
+	  else if (ptr_star_count == 0)
+	    {
+	      /* If ptr_type was not really a pointer to type, it cannot 
+		 alias.  */ 
+	      alias_stats.structnoaddress_queries++;
+	      alias_stats.structnoaddress_resolved++;
+	      alias_stats.alias_noalias++;
+	      return false;
+	    }
 	}
     }
 

contrib/gcc/tree-ssa-dce.c

@@ -1,6 +1,5 @@
 /* Dead code elimination pass for the GNU compiler.
-   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007
+   Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
-   Free Software Foundation, Inc.
    Contributed by Ben Elliston <bje@redhat.com>
    and Andrew MacLeod <amacleod@redhat.com>
    Adapted to use control dependence by Steven Bosscher, SUSE Labs.
@@ -308,7 +307,6 @@ mark_stmt_if_obviously_necessary (tree stmt, bool aggressive)
     case ASM_EXPR:
     case RESX_EXPR:
     case RETURN_EXPR:
-    case CHANGE_DYNAMIC_TYPE_EXPR:
       mark_stmt_necessary (stmt, true);
       return;
 

contrib/gcc/tree-ssa-operands.c

@@ -2057,10 +2057,6 @@ get_expr_operands (tree stmt, tree *expr_p, int flags)
         return;
       }
 
-    case CHANGE_DYNAMIC_TYPE_EXPR:
-      get_expr_operands (stmt, &CHANGE_DYNAMIC_TYPE_LOCATION (expr), opf_none);
-      return;
-
     case BLOCK:
     case FUNCTION_DECL:
     case EXC_PTR_EXPR:

contrib/gcc/tree-ssa-structalias.c

@@ -251,10 +251,6 @@ struct variable_info
   /* True if this is a heap variable.  */
   unsigned int is_heap_var:1;
 
-  /* True if we may not use TBAA to prune references to this
-     variable.  This is used for C++ placement new.  */
-  unsigned int no_tbaa_pruning : 1;
-
   /* Points-to set for this variable.  */
   bitmap solution;
 
@@ -372,7 +368,6 @@ static varinfo_t
 new_var_info (tree t, unsigned int id, const char *name)
 {
   varinfo_t ret = pool_alloc (variable_info_pool);
-  tree var;
 
   ret->id = id;
   ret->name = name;
@@ -383,12 +378,6 @@ new_var_info (tree t, unsigned int id, const char *name)
   ret->is_special_var = false;
   ret->is_unknown_size_var = false;
   ret->has_union = false;
-  var = t;
-  if (TREE_CODE (var) == SSA_NAME)
-    var = SSA_NAME_VAR (var);
-  ret->no_tbaa_pruning = (DECL_P (var)
-			  && POINTER_TYPE_P (TREE_TYPE (var))
-			  && DECL_NO_TBAA_P (var));
   ret->solution = BITMAP_ALLOC (&pta_obstack);
   ret->oldsolution = BITMAP_ALLOC (&oldpta_obstack);
   ret->next = NULL;
@@ -1232,9 +1221,6 @@ unify_nodes (constraint_graph_t graph, unsigned int to, unsigned int from,
   merge_graph_nodes (graph, to, from);
   merge_node_constraints (graph, to, from);
 
-  if (get_varinfo (from)->no_tbaa_pruning)
-    get_varinfo (to)->no_tbaa_pruning = true;
-
   if (update_changed && TEST_BIT (changed, from))
     {
       RESET_BIT (changed, from);
@@ -3578,14 +3564,6 @@ find_func_aliases (tree origt)
 	    }
 	}
     }
-  else if (TREE_CODE (t) == CHANGE_DYNAMIC_TYPE_EXPR)
-    {
-      unsigned int j;
-
-      get_constraint_for (CHANGE_DYNAMIC_TYPE_LOCATION (t), &lhsc);
-      for (j = 0; VEC_iterate (ce_s, lhsc, j, c); ++j)
-	get_varinfo (c->var)->no_tbaa_pruning = true;
-    }
 
   /* After promoting variables and computing aliasing we will
      need to re-scan most statements.  FIXME: Try to minimize the
@@ -4272,10 +4250,7 @@ dump_solution_for_var (FILE *file, unsigned int var)
 	{
 	  fprintf (file, "%s ", get_varinfo (i)->name);
 	}
-      fprintf (file, "}");
+      fprintf (file, "}\n");
-      if (vi->no_tbaa_pruning)
-	fprintf (file, " no-tbaa-pruning");
-      fprintf (file, "\n");
     }
 }
 
@@ -4447,15 +4422,10 @@ shared_bitmap_add (bitmap pt_vars)
 /* Set bits in INTO corresponding to the variable uids in solution set
    FROM, which came from variable PTR.
    For variables that are actually dereferenced, we also use type
-   based alias analysis to prune the points-to sets.
+   based alias analysis to prune the points-to sets.  */
-   IS_DEREFED is true if PTR was directly dereferenced, which we use to
-   help determine whether we are we are allowed to prune using TBAA.
-   If NO_TBAA_PRUNING is true, we do not perform any TBAA pruning of
-   the from set.  */
 
 static void
-set_uids_in_ptset (tree ptr, bitmap into, bitmap from, bool is_derefed,
+set_uids_in_ptset (tree ptr, bitmap into, bitmap from)
-		   bool no_tbaa_pruning)
 {
   unsigned int i;
   bitmap_iterator bi;
@@ -4492,8 +4462,7 @@ set_uids_in_ptset (tree ptr, bitmap into, bitmap from, bool is_derefed,
 	      if (sft)
 		{
 		  var_alias_set = get_alias_set (sft);
-		  if (no_tbaa_pruning
+		  if (!vi->directly_dereferenced
-		      || (!is_derefed && !vi->directly_dereferenced)
 		      || alias_sets_conflict_p (ptr_alias_set, var_alias_set))
 		    bitmap_set_bit (into, DECL_UID (sft));
 		}
@@ -4507,8 +4476,7 @@ set_uids_in_ptset (tree ptr, bitmap into, bitmap from, bool is_derefed,
 	      else
 		{
 		  var_alias_set = get_alias_set (vi->decl);
-		  if (no_tbaa_pruning
+		  if (!vi->directly_dereferenced
-		      || (!is_derefed && !vi->directly_dereferenced)
 		      || alias_sets_conflict_p (ptr_alias_set, var_alias_set))
 		    bitmap_set_bit (into, DECL_UID (vi->decl));
 		}
@@ -4596,9 +4564,7 @@ find_what_p_points_to (tree p)
 	    return false;
 
 	  finished_solution = BITMAP_GGC_ALLOC ();
-	  set_uids_in_ptset (vi->decl, finished_solution, vi->solution,
+	  set_uids_in_ptset (vi->decl, finished_solution, vi->solution);
-	  		     vi->directly_dereferenced,
-			     vi->no_tbaa_pruning);
 	  result = shared_bitmap_lookup (finished_solution);
 
 	  if (!result)
@@ -4947,142 +4913,6 @@ remove_preds_and_fake_succs (constraint_graph_t graph)
   bitmap_obstack_release (&predbitmap_obstack);
 }
 
-/* Compute the set of variables we can't TBAA prune.  */
-
-static void
-compute_tbaa_pruning (void)
-{
-  unsigned int size = VEC_length (varinfo_t, varmap);
-  unsigned int i;
-  bool any;
-
-  changed_count = 0;
-  changed = sbitmap_alloc (size);
-  sbitmap_zero (changed);
-
-  /* Mark all initial no_tbaa_pruning nodes as changed.  */
-  any = false;
-  for (i = 0; i < size; ++i)
-    {
-      varinfo_t ivi = get_varinfo (i);
-
-      if (find (i) == i && ivi->no_tbaa_pruning)
-	{
-	  any = true;
-	  if ((graph->succs[i] && !bitmap_empty_p (graph->succs[i]))
-	      || VEC_length (constraint_t, graph->complex[i]) > 0)
-	    {
-	      SET_BIT (changed, i);
-	      ++changed_count;
-	    }
-	}
-    }
-
-  while (changed_count > 0)
-    {
-      struct topo_info *ti = init_topo_info ();
-      ++stats.iterations;
-
-      bitmap_obstack_initialize (&iteration_obstack);
-
-      compute_topo_order (graph, ti);
-
-      while (VEC_length (unsigned, ti->topo_order) != 0)
-	{
-	  bitmap_iterator bi;
-
-	  i = VEC_pop (unsigned, ti->topo_order);
-
-	  /* If this variable is not a representative, skip it.  */
-	  if (find (i) != i)
-	    continue;
-
-	  /* If the node has changed, we need to process the complex
-	     constraints and outgoing edges again.  */
-	  if (TEST_BIT (changed, i))
-	    {
-	      unsigned int j;
-	      constraint_t c;
-	      VEC(constraint_t,heap) *complex = graph->complex[i];
-
-	      RESET_BIT (changed, i);
-	      --changed_count;
-
-	      /* Process the complex copy constraints.  */
-	      for (j = 0; VEC_iterate (constraint_t, complex, j, c); ++j)
-		{
-		  if (c->lhs.type == SCALAR && c->rhs.type == SCALAR)
-		    {
-		      varinfo_t lhsvi = get_varinfo (find (c->lhs.var));
-
-		      if (!lhsvi->no_tbaa_pruning)
-			{
-			  lhsvi->no_tbaa_pruning = true;
-			  if (!TEST_BIT (changed, lhsvi->id))
-			    {
-			      SET_BIT (changed, lhsvi->id);
-			      ++changed_count;
-			    }
-			}
-		    }
-		}
-
-	      /* Propagate to all successors.  */
-	      EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[i], 0, j, bi)
-		{
-		  unsigned int to = find (j);
-		  varinfo_t tovi = get_varinfo (to);
-
-		  /* Don't propagate to ourselves.  */
-		  if (to == i)
-		    continue;
-
-		  if (!tovi->no_tbaa_pruning)
-		    {
-		      tovi->no_tbaa_pruning = true;
-		      if (!TEST_BIT (changed, to))
-			{
-			  SET_BIT (changed, to);
-			  ++changed_count;
-			}
-		    }
-		}
-	    }
-	}
-
-      free_topo_info (ti);
-      bitmap_obstack_release (&iteration_obstack);
-    }
-
-  sbitmap_free (changed);
-
-  if (any)
-    {
-      for (i = 0; i < size; ++i)
-	{
-	  varinfo_t ivi = get_varinfo (i);
-	  varinfo_t ivip = get_varinfo (find (i));
-
-	  if (ivip->no_tbaa_pruning)
-	    {
-	      tree var = ivi->decl;
-
-	      if (TREE_CODE (var) == SSA_NAME)
-		var = SSA_NAME_VAR (var);
-
-	      if (POINTER_TYPE_P (TREE_TYPE (var)))
-		{
-		  DECL_NO_TBAA_P (var) = 1;
-
-		  /* Tell the RTL layer that this pointer can alias
-		     anything.  */
-		  DECL_POINTER_ALIAS_SET (var) = 0;
-		}
-	    }
-	}
-    }
-}
-
 /* Create points-to sets for the current function.  See the comments
    at the start of the file for an algorithmic overview.  */
 
@@ -5118,7 +4948,7 @@ compute_points_to_sets (struct alias_info *ai)
 	    }
 	}
 
-      for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
+      for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
 	{
 	  tree stmt = bsi_stmt (bsi);
 
@@ -5129,13 +4959,6 @@ compute_points_to_sets (struct alias_info *ai)
 	     This is used when creating name tags and alias
 	     sets.  */
 	  update_alias_info (stmt, ai);
-
-	  /* The information in CHANGE_DYNAMIC_TYPE_EXPR nodes has now
-	     been captured, and we can remove them.  */
-	  if (TREE_CODE (stmt) == CHANGE_DYNAMIC_TYPE_EXPR)
-	    bsi_remove (&bsi, true);
-	  else
-	    bsi_next (&bsi);
 	}
     }
 
@@ -5168,8 +4991,6 @@ compute_points_to_sets (struct alias_info *ai)
 
   solve_graph (graph);
 
-  compute_tbaa_pruning ();
-
   if (dump_file)
     dump_sa_points_to_info (dump_file);
   have_alias_info = true;

contrib/gcc/tree.def

@@ -1,7 +1,7 @@
 /* This file contains the definitions and documentation for the
    tree codes used in GCC.
    Copyright (C) 1987, 1988, 1993, 1995, 1997, 1998, 2000, 2001, 2004, 2005, 
-   2006, 2007 Free Software Foundation, Inc.
+   2006 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -880,15 +880,6 @@ DEFTREECODE (CATCH_EXPR, "catch_expr", tcc_statement, 2)
    expanding.  */
 DEFTREECODE (EH_FILTER_EXPR, "eh_filter_expr", tcc_statement, 2)
 
-/* Indicates a change in the dynamic type of a memory location.  This
-   has no value and generates no executable code.  It is only used for
-   type based alias analysis.  This is generated by C++ placement new.
-   CHANGE_DYNAMIC_TYPE_NEW_TYPE, the first operand, is the new type.
-   CHNAGE_DYNAMIC_TYPE_LOCATION, the second operand, is the location
-   whose type is being changed.  */
-DEFTREECODE (CHANGE_DYNAMIC_TYPE_EXPR, "change_dynamic_type_expr",
-	     tcc_statement, 2)
-
 /* Node used for describing a property that is known at compile
    time.  */
 DEFTREECODE (SCEV_KNOWN, "scev_known", tcc_expression, 0)

contrib/gcc/tree.h

@@ -1548,12 +1548,6 @@ struct tree_constructor GTY(())
 #define EH_FILTER_FAILURE(NODE)	TREE_OPERAND (EH_FILTER_EXPR_CHECK (NODE), 1)
 #define EH_FILTER_MUST_NOT_THROW(NODE) TREE_STATIC (EH_FILTER_EXPR_CHECK (NODE))
 
-/* CHANGE_DYNAMIC_TYPE_EXPR accessors.  */
-#define CHANGE_DYNAMIC_TYPE_NEW_TYPE(NODE) \
-  TREE_OPERAND (CHANGE_DYNAMIC_TYPE_EXPR_CHECK (NODE), 0)
-#define CHANGE_DYNAMIC_TYPE_LOCATION(NODE) \
-  TREE_OPERAND (CHANGE_DYNAMIC_TYPE_EXPR_CHECK (NODE), 1)
-
 /* OBJ_TYPE_REF accessors.  */
 #define OBJ_TYPE_REF_EXPR(NODE)	  TREE_OPERAND (OBJ_TYPE_REF_CHECK (NODE), 0)
 #define OBJ_TYPE_REF_OBJECT(NODE) TREE_OPERAND (OBJ_TYPE_REF_CHECK (NODE), 1)
@@ -2544,11 +2538,6 @@ struct tree_struct_field_tag GTY(())
 #define DECL_CALL_CLOBBERED(DECL) \
   DECL_COMMON_CHECK (DECL)->decl_common.call_clobbered_flag
 
-/* For a DECL with pointer type, this is set if Type Based Alias
-   Analysis should not be applied to this DECL.  */
-#define DECL_NO_TBAA_P(DECL) \
-  DECL_COMMON_CHECK (DECL)->decl_common.no_tbaa_flag
-
 struct tree_decl_common GTY(())
 {
   struct tree_decl_minimal common;
@@ -2590,8 +2579,6 @@ struct tree_decl_common GTY(())
      parm decl. */
   unsigned gimple_reg_flag : 1;
   unsigned call_clobbered_flag : 1;
-  /* In a DECL with pointer type, set if no TBAA should be done.  */
-  unsigned no_tbaa_flag : 1;
 
   unsigned int align : 24;
   /* DECL_OFFSET_ALIGN, used only for FIELD_DECLs.  */