diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 2639c8c..54a0ef9 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -10548,6 +10548,8 @@ ix86_build_builtin_va_list_64 (void)
 
   layout_type (record);
 
+  TYPE_ATTRIBUTES (record) = tree_cons (get_identifier ("sysv_abi"), NULL_TREE, NULL_TREE);
+
   /* The correct type is an array type of one element.  */
   return build_array_type (record, build_index_type (size_zero_node));
 }
@@ -10561,16 +10563,16 @@ ix86_build_builtin_va_list (void)
   if (TARGET_64BIT)
     {
       /* Initialize ABI specific va_list builtin types.  */
-      tree sysv_va_list, ms_va_list;
-
-      sysv_va_list = ix86_build_builtin_va_list_64 ();
-      sysv_va_list_type_node = build_variant_type_copy (sysv_va_list);
+      sysv_va_list_type_node = ix86_build_builtin_va_list_64 ();
 	
       /* For MS_ABI we use plain pointer to argument area.  */
-      ms_va_list = build_pointer_type (char_type_node);
-      ms_va_list_type_node = build_variant_type_copy (ms_va_list);
+      tree char_ptr_type = build_pointer_type (char_type_node);
+      tree attr = tree_cons (get_identifier ("ms_abi"), NULL_TREE, NULL_TREE);
+      ms_va_list_type_node = build_type_attribute_variant (char_ptr_type, attr);
 
-      return (ix86_abi == MS_ABI) ? ms_va_list : sysv_va_list;
+      return ((ix86_abi == MS_ABI)
+	      ? ms_va_list_type_node
+	      : sysv_va_list_type_node);
     }
   else
     {
@@ -48563,8 +48565,6 @@ ix86_fn_abi_va_list (tree fndecl)
 static tree
 ix86_canonical_va_list_type (tree type)
 {
-  tree wtype, htype;
-
   /* Resolve references and pointers to va_list type.  */
   if (TREE_CODE (type) == MEM_REF)
     type = TREE_TYPE (type);
@@ -48573,64 +48573,24 @@ ix86_canonical_va_list_type (tree type)
   else if (POINTER_TYPE_P (type) && TREE_CODE (TREE_TYPE (type)) == ARRAY_TYPE)
     type = TREE_TYPE (type);
 
-  if (TARGET_64BIT && va_list_type_node != NULL_TREE)
+  if (TARGET_64BIT)
     {
-      wtype = va_list_type_node;
-	  gcc_assert (wtype != NULL_TREE);
-      htype = type;
-      if (TREE_CODE (wtype) == ARRAY_TYPE)
-	{
-	  /* If va_list is an array type, the argument may have decayed
-	     to a pointer type, e.g. by being passed to another function.
-	     In that case, unwrap both types so that we can compare the
-	     underlying records.  */
-	  if (TREE_CODE (htype) == ARRAY_TYPE
-	      || POINTER_TYPE_P (htype))
-	    {
-	      wtype = TREE_TYPE (wtype);
-	      htype = TREE_TYPE (htype);
-	    }
-	}
-      if (TYPE_MAIN_VARIANT (wtype) == TYPE_MAIN_VARIANT (htype))
-	return va_list_type_node;
-      wtype = sysv_va_list_type_node;
-	  gcc_assert (wtype != NULL_TREE);
-      htype = type;
-      if (TREE_CODE (wtype) == ARRAY_TYPE)
-	{
-	  /* If va_list is an array type, the argument may have decayed
-	     to a pointer type, e.g. by being passed to another function.
-	     In that case, unwrap both types so that we can compare the
-	     underlying records.  */
-	  if (TREE_CODE (htype) == ARRAY_TYPE
-	      || POINTER_TYPE_P (htype))
-	    {
-	      wtype = TREE_TYPE (wtype);
-	      htype = TREE_TYPE (htype);
-	    }
-	}
-      if (TYPE_MAIN_VARIANT (wtype) == TYPE_MAIN_VARIANT (htype))
-	return sysv_va_list_type_node;
-      wtype = ms_va_list_type_node;
-	  gcc_assert (wtype != NULL_TREE);
-      htype = type;
-      if (TREE_CODE (wtype) == ARRAY_TYPE)
+      if (lookup_attribute ("ms_abi", TYPE_ATTRIBUTES (type)))
+	return ms_va_list_type_node;
+
+      if ((TREE_CODE (type) == ARRAY_TYPE
+	   && integer_zerop (array_type_nelts (type)))
+	  || POINTER_TYPE_P (type))
 	{
-	  /* If va_list is an array type, the argument may have decayed
-	     to a pointer type, e.g. by being passed to another function.
-	     In that case, unwrap both types so that we can compare the
-	     underlying records.  */
-	  if (TREE_CODE (htype) == ARRAY_TYPE
-	      || POINTER_TYPE_P (htype))
-	    {
-	      wtype = TREE_TYPE (wtype);
-	      htype = TREE_TYPE (htype);
-	    }
+	  tree elem_type = TREE_TYPE (type);
+	  if (TREE_CODE (elem_type) == RECORD_TYPE
+	      && lookup_attribute ("sysv_abi", TYPE_ATTRIBUTES (elem_type)))
+	    return sysv_va_list_type_node;
 	}
-      if (TYPE_MAIN_VARIANT (wtype) == TYPE_MAIN_VARIANT (htype))
-	return ms_va_list_type_node;
+
       return NULL_TREE;
     }
+
   return std_canonical_va_list_type (type);
 }
 
