re PR c++/34862 (operator new placement variant with reference arg not accepted by g++ 4.3)

	PR c++/34862
	PR c++/33407
	* tree-ssa-copyrename.c (copy_rename_partition_coalesce): Don't
	coalesce pointers if they have different DECL_NO_TBAA_P values.
	* tree-ssa-copy.c (may_propagate_copy): Don't propagate copies
	between variables with different DECL_NO_TBAA_P values.

From-SVN: r131916

gcc/ChangeLog

+2008-01-28  Ian Lance Taylor  <iant@google.com>
+
+	PR c++/34862
+	PR c++/33407
+	* tree-ssa-copyrename.c (copy_rename_partition_coalesce): Don't
+	coalesce pointers if they have different DECL_NO_TBAA_P values.
+	* tree-ssa-copy.c (may_propagate_copy): Don't propagate copies
+	between variables with different DECL_NO_TBAA_P values.
+
 2008-01-28  Nathan Froyd  <froydnj@codesourcery.com>
 
 	PR 31535

gcc/tree-ssa-copy.c

 /* Copy propagation and SSA_NAME replacement support routines.
-   Copyright (C) 2004, 2005, 2007 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -143,6 +143,11 @@ may_propagate_copy (tree dest, tree orig)
       else if (get_alias_set (TREE_TYPE (type_d)) != 
 	       get_alias_set (TREE_TYPE (type_o)))
 	return false;
+      else if (!MTAG_P (SSA_NAME_VAR (dest))
+	       && !MTAG_P (SSA_NAME_VAR (orig))
+	       && (DECL_NO_TBAA_P (SSA_NAME_VAR (dest))
+		   != DECL_NO_TBAA_P (SSA_NAME_VAR (orig))))
+	return false;
 
       /* Also verify flow-sensitive information is compatible.  */
       if (SSA_NAME_PTR_INFO (orig) && SSA_NAME_PTR_INFO (dest))

gcc/tree-ssa-copyrename.c

 /* Rename SSA copies.
-   Copyright (C) 2004, 2007 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2006, 2007, 2008 Free Software Foundation, Inc.
    Contributed by Andrew MacLeod <amacleod@redhat.com>
 
 This file is part of GCC.
@@ -249,8 +249,11 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
   /* Don't coalesce if the aliasing sets of the types are different.  */
   if (POINTER_TYPE_P (TREE_TYPE (root1))
       && POINTER_TYPE_P (TREE_TYPE (root2))
-      && get_alias_set (TREE_TYPE (TREE_TYPE (root1)))
-          != get_alias_set (TREE_TYPE (TREE_TYPE (root2))))
+      && ((get_alias_set (TREE_TYPE (TREE_TYPE (root1)))
+	   != get_alias_set (TREE_TYPE (TREE_TYPE (root2))))
+	  || ((DECL_P (root1) && !MTAG_P (root1))
+	      && (DECL_P (root2) && !MTAG_P (root2))
+	      && DECL_NO_TBAA_P (root1) != DECL_NO_TBAA_P (root2))))
     {
       if (debug)
 	fprintf (debug, " : 2 different aliasing sets. No coalesce.\n");