diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d8b56f6472f..217b0097062 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2019-06-19  Kugan Vivekanandarajah  <kugan.vivekanandarajah@linaro.org>
+
+	* tree-ssa-address.c (preferred_mem_scale_factor): Handle when
+	mem_mode is BLKmode.
+
 2019-06-18  Max Filippov  <jcmvbkbc@gmail.com>
 
 	PR target/90922
diff --git a/gcc/tree-ssa-address.c b/gcc/tree-ssa-address.c
index cdd432a6e1a..e83e1b9296f 100644
--- a/gcc/tree-ssa-address.c
+++ b/gcc/tree-ssa-address.c
@@ -1134,6 +1134,10 @@ unsigned int
 preferred_mem_scale_factor (tree base, machine_mode mem_mode,
 			    bool speed)
 {
+  /* For BLKmode, we can't do anything so return 1.  */
+  if (mem_mode == BLKmode)
+    return 1;
+
   struct mem_address parts = {};
   addr_space_t as = TYPE_ADDR_SPACE (TREE_TYPE (base));
   unsigned int fact = GET_MODE_UNIT_SIZE (mem_mode);