diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6ea25f8a9b5..8d8e8d8187d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2018-05-04  Tom de Vries  <tom@codesourcery.com>
+
+	PR libgomp/85639
+	* builtins.c (expand_builtin_goacc_parlevel_id_size): Handle null target
+	if ignore == 0.
+
 2018-05-04  Richard Biener  <rguenther@suse.de>
 
 	PR middle-end/85627
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 300e13c2f47..0097d5bae97 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -6682,6 +6682,9 @@ expand_builtin_goacc_parlevel_id_size (tree exp, rtx target, int ignore)
   if (ignore)
     return target;
 
+  if (target == NULL_RTX)
+    target = gen_reg_rtx (TYPE_MODE (TREE_TYPE (exp)));
+
   if (!targetm.have_oacc_dim_size ())
     {
       emit_move_insn (target, fallback_retval);