tree-stdarg.c (execute_optimize_stdarg): Handle references to va_list of the form &va[0].

2005-05-21  Richard Guenther  <rguenth@gcc.gnu.org>

	* tree-stdarg.c (execute_optimize_stdarg): Handle references
	to va_list of the form &va[0].

From-SVN: r100043

gcc/ChangeLog

+2005-05-21  Richard Guenther  <rguenth@gcc.gnu.org>
+
+	* tree-stdarg.c (execute_optimize_stdarg): Handle references
+	to va_list of the form &va[0].
+
 2005-05-20  Jan Hubicka  <jh@suse.cz>
 
 	* Makefile.in (insn-emit.o): Add basic-block.h dependency.

gcc/tree-stdarg.c

@@ -660,16 +660,30 @@ execute_optimize_stdarg (void)
 
 	  si.va_start_count++;
 	  ap = TREE_VALUE (TREE_OPERAND (call, 1));
-	  if (TREE_CODE (ap) != ADDR_EXPR
-	      || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (ap, 0)))
-		 != TYPE_MAIN_VARIANT (va_list_type_node)
-	      || TREE_CODE (TREE_OPERAND (ap, 0)) != VAR_DECL)
+
+	  if (TREE_CODE (ap) != ADDR_EXPR)
 	    {
 	      va_list_escapes = true;
 	      break;
 	    }
-
 	  ap = TREE_OPERAND (ap, 0);
+	  if (TREE_CODE (ap) == ARRAY_REF)
+	    {
+	      if (! integer_zerop (TREE_OPERAND (ap, 1)))
+	        {
+	          va_list_escapes = true;
+	          break;
+		}
+	      ap = TREE_OPERAND (ap, 0);
+	    }
+	  if (TYPE_MAIN_VARIANT (TREE_TYPE (ap))
+	      != TYPE_MAIN_VARIANT (va_list_type_node)
+	      || TREE_CODE (ap) != VAR_DECL)
+	    {
+	      va_list_escapes = true;
+	      break;
+	    }
+
 	  if (is_global_var (ap))
 	    {
 	      va_list_escapes = true;