diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ef793e4d8cc..0e0257d9675 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2017-09-13  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* gimple-ssa-store-merging.c (sort_by_bitpos): Compare store order
+	when bitposition is the same.
+
 2017-09-13  Richard Biener  <rguenther@suse.de>
 
 	* dwarf2out.c (output_die_symbol): Remove.
diff --git a/gcc/gimple-ssa-store-merging.c b/gcc/gimple-ssa-store-merging.c
index a4a38b104bf..cb764032205 100644
--- a/gcc/gimple-ssa-store-merging.c
+++ b/gcc/gimple-ssa-store-merging.c
@@ -521,7 +521,9 @@ sort_by_bitpos (const void *x, const void *y)
   else if ((*tmp)->bitpos > (*tmp2)->bitpos)
     return 1;
   else
-    return 0;
+    /* If they are the same let's use the order which is guaranteed to
+       be different.  */
+    return (*tmp)->order - (*tmp2)->order;
 }
 
 /* Sorting function for store_immediate_info objects.