diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d4ee2a2754c..6b3437fe7b0 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-02-01  Richard Biener  <rguenth@suse.de>
+
+	PR rtl-optimization/88593
+	* mode-switching.c (optimize_mode_switching): Free dominators before
+	calling cleanup_cfg.
+
 2019-02-01  Bin Cheng  <bin.cheng@linux.alibaba.com>
 
 	PR tree-optimization/88932
diff --git a/gcc/mode-switching.c b/gcc/mode-switching.c
index ef6f6e1984c..2ff21a40081 100644
--- a/gcc/mode-switching.c
+++ b/gcc/mode-switching.c
@@ -856,7 +856,10 @@ optimize_mode_switching (void)
     commit_edge_insertions ();
 
   if (targetm.mode_switching.entry && targetm.mode_switching.exit)
-    cleanup_cfg (CLEANUP_NO_INSN_DEL);
+    {
+      free_dominance_info (CDI_DOMINATORS);
+      cleanup_cfg (CLEANUP_NO_INSN_DEL);
+    }
   else if (!need_commit && !emitted)
     return 0;