tree-dfa.c (remove_referenced_var): New function.

	* tree-dfa.c (remove_referenced_var): New function.
	* tree-ssa-live.c (remove_unused_locals): Walk referenced vars and
	prune referenced vars list too.
	* tree-flow.h (remove_referenced_var): Declare.

From-SVN: r120767

gcc/ChangeLog

 2007-01-14  Jan Hubicka  <jh@suse.cz>
 
+	* tree-dfa.c (remove_referenced_var): New function.
+	* tree-ssa-live.c (remove_unused_locals): Walk referenced vars and
+	prune referenced vars list too.
+	* tree-flow.h (remove_referenced_var): Declare.
+
+2007-01-14  Jan Hubicka  <jh@suse.cz>
+
 	* tree-eh.c (add_stmt_to_eh_region_fn): Do not add call_exprs
 	separately.
 	(remove_stmt_from_eh_region_fn): Do not remove call_exprs.

gcc/tree-dfa.c

@@ -752,6 +752,29 @@ add_referenced_var (tree var)
     }
 }
 
+/* Remove VAR from the list.  */
+
+void
+remove_referenced_var (tree var)
+{
+  var_ann_t v_ann;
+  struct int_tree_map in;
+  void **loc;
+  unsigned int uid = DECL_UID (var);
+
+  clear_call_clobbered (var);
+  v_ann = get_var_ann (var);
+  ggc_free (v_ann);
+  var->base.ann = NULL;
+  gcc_assert (DECL_P (var));
+  in.uid = uid;
+  in.to = var;
+  loc = htab_find_slot_with_hash (gimple_referenced_vars (cfun), &in, uid,
+				  NO_INSERT);
+  ggc_free (*loc);
+  htab_clear_slot (gimple_referenced_vars (cfun), loc);
+}
+
 
 /* Return the virtual variable associated to the non-scalar variable VAR.  */
 

gcc/tree-flow.h

@@ -698,6 +698,7 @@ extern void dump_subvars_for (FILE *, tree);
 extern void debug_subvars_for (tree);
 extern tree get_virtual_var (tree);
 extern void add_referenced_var (tree);
+extern void remove_referenced_var (tree);
 extern void mark_symbols_for_renaming (tree);
 extern void find_new_referenced_vars (tree *);
 

gcc/tree-ssa-live.c

@@ -449,15 +449,12 @@ remove_unused_locals (void)
 {
   basic_block bb;
   tree t, *cell;
+  referenced_var_iterator rvi;
+  var_ann_t ann;
 
   /* Assume all locals are unused.  */
-  for (t = cfun->unexpanded_var_list; t; t = TREE_CHAIN (t))
-    {
-      tree var = TREE_VALUE (t);
-      if (TREE_CODE (var) != FUNCTION_DECL
-	  && var_ann (var))
-	var_ann (var)->used = false;
-    }
+  FOR_EACH_REFERENCED_VAR (t, rvi)
+    var_ann (t)->used = false;
 
   /* Walk the CFG marking all referenced symbols.  */
   FOR_EACH_BB (bb)
@@ -493,7 +490,6 @@ remove_unused_locals (void)
   for (cell = &cfun->unexpanded_var_list; *cell; )
     {
       tree var = TREE_VALUE (*cell);
-      var_ann_t ann;
 
       if (TREE_CODE (var) != FUNCTION_DECL
 	  && (!(ann = var_ann (var))
@@ -505,6 +501,19 @@ remove_unused_locals (void)
 
       cell = &TREE_CHAIN (*cell);
     }
+
+  /* Remove unused variables from REFERENCED_VARs.  As an special exception
+     keep the variables that are believed to be aliased.  Those can't be
+     easilly removed from the alias sets and and operand caches.
+     They will be removed shortly after next may_alias pass is performed.  */
+  FOR_EACH_REFERENCED_VAR (t, rvi)
+    if (!is_global_var (t)
+	&& !MTAG_P (t)
+	&& TREE_CODE (t) != PARM_DECL
+	&& TREE_CODE (t) != RESULT_DECL
+	&& !(ann = var_ann (t))->used
+	&& !ann->is_aliased && !is_call_clobbered (t) && !ann->symbol_mem_tag)
+        remove_referenced_var (t);
 }