2008-06-12 Richard Guenther <rguenther@suse.de>

	PR tree-optimization/36345
	* tree-flow.h (struct ptr_info_def): Align escape_mask,
	add memory_tag_needed flag.
	(may_alias_p): Declare.
	* tree-ssa-alias.c (may_alias_p): Export.
	(set_initial_properties): Use memory_tag_needed flag.
	(update_reference_counts): Likewise.
	(reset_alias_info): Reset memory_tag_needed flag.
	(create_name_tags): Check memory_tag_needed flag.
	(dump_points_to_info_for): Dump it.
	* tree-ssa-structalias.c (struct variable_info): Remove
	directly_dereferenced flag.
	(new_var_info): Do not initialize it.
	(process_constraint_1): Do not set it.
	(update_alias_info): Set is_dereferenced flag.
	(set_uids_in_ptset): Use may_alias_p.
	(set_used_smts): Check memory_tag_needed flag.
	(find_what_p_points_to): Likewise.  Pass is_dereferenced flag.
	* tree-ssa-alias.c (verify_flow_sensitive_alias_info): Check
	memory_tag_needed flag.
	* tree-ssa-alias-warnings.c (dsa_named_for): Try to recover
	from broken design.

	* gcc.c-torture/execute/20020619-1.c: Remove broken part of
	the testcase.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@136695 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 8 insertions, 6 deletions

diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index e89e73b9f59..0e5071994de 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -197,7 +197,6 @@ static bitmap_obstack alias_bitmap_obstack;
 /* Local functions.  */
 static void compute_flow_insensitive_aliasing (struct alias_info *);
 static void dump_alias_stats (FILE *);
-static bool may_alias_p (tree, alias_set_type, tree, alias_set_type, bool);
 static tree create_memory_tag (tree type, bool is_type_tag);
 static tree get_smt_for (tree, struct alias_info *);
 static tree get_nmt_for (tree);
@@ -588,14 +587,14 @@ set_initial_properties (struct alias_info *ai)
          So removing this code and fixing all the bugs would be nice.
          It is the cause of a bunch of clobbering.  */
       if ((pi->pt_global_mem || pi->pt_anything) 
-	  && pi->is_dereferenced && pi->name_mem_tag)
+	  && pi->memory_tag_needed && pi->name_mem_tag)
 	{
 	  mark_call_clobbered (pi->name_mem_tag, ESCAPE_IS_GLOBAL);
 	  MTAG_GLOBAL (pi->name_mem_tag) = true;
 	}
       
       if ((pi->pt_global_mem || pi->pt_anything) 
-	  && pi->is_dereferenced
+	  && pi->memory_tag_needed
 	  && tag)
 	{
 	  mark_call_clobbered (tag, ESCAPE_IS_GLOBAL);
@@ -1278,7 +1277,7 @@ update_reference_counts (struct mem_ref_stats_d *mem_ref_stats)
       if (ptr
 	  && POINTER_TYPE_P (TREE_TYPE (ptr))
 	  && (pi = SSA_NAME_PTR_INFO (ptr)) != NULL
-	  && pi->is_dereferenced)
+	  && pi->memory_tag_needed)
 	{
 	  unsigned j;
 	  bitmap_iterator bj;
@@ -2027,6 +2026,7 @@ reset_alias_info (void)
 	  pi->pt_anything = 0;
 	  pi->pt_null = 0;
 	  pi->value_escapes_p = 0;
+	  pi->memory_tag_needed = 0;
 	  pi->is_dereferenced = 0;
 	  if (pi->pt_vars)
 	    bitmap_clear (pi->pt_vars);
@@ -2170,7 +2170,7 @@ create_name_tags (void)
 
       pi = SSA_NAME_PTR_INFO (ptr);
 
-      if (pi->pt_anything || !pi->is_dereferenced)
+      if (pi->pt_anything || !pi->memory_tag_needed)
 	{
 	  /* No name tags for pointers that have not been
 	     dereferenced or point to an arbitrary location.  */
@@ -2649,7 +2649,7 @@ maybe_create_global_var (void)
    
    VAR_ALIAS_SET is the alias set for VAR.  */
 
-static bool
+bool
 may_alias_p (tree ptr, alias_set_type mem_alias_set,
 	     tree var, alias_set_type var_alias_set,
 	     bool alias_set_only)
@@ -3231,6 +3231,8 @@ dump_points_to_info_for (FILE *file, tree ptr)
 
       if (pi->is_dereferenced)
 	fprintf (file, ", is dereferenced");
+      else if (pi->memory_tag_needed)
+	fprintf (file, ", is dereferenced in call");
 
       if (pi->value_escapes_p)
 	fprintf (file, ", its value escapes");