diff --git a/src/hb-bit-set.hh b/src/hb-bit-set.hh
index 81f8db958..84e80885e 100644
--- a/src/hb-bit-set.hh
+++ b/src/hb-bit-set.hh
@@ -203,7 +203,7 @@ struct hb_bit_set_t
   bool set_sorted_array (bool v, const T *array, unsigned int count, unsigned int stride=sizeof(T))
   {
     if (unlikely (!successful)) return true; /* https://github.com/harfbuzz/harfbuzz/issues/657 */
-    if (!count) return true;
+    if (unlikely (!count)) return true;
     dirty ();
     hb_codepoint_t g = *array;
     hb_codepoint_t last_g = g;
@@ -222,7 +222,7 @@ struct hb_bit_set_t
         if (v || page) /* The v check is to optimize out the page check if v is true. */
 	  page->add (g);
 
-	array = (const T *) ((const char *) array + stride);
+	array = &StructAtOffsetUnaligned<T> (array, stride);
 	count--;
       }
       while (count && (g = *array, g < end));
diff --git a/src/hb-set.cc b/src/hb-set.cc
index 204dbb564..54c5b2136 100644
--- a/src/hb-set.cc
+++ b/src/hb-set.cc
@@ -61,6 +61,24 @@ hb_set_create ()
   return set;
 }
 
+/**
+ * Creates a set initially populated with num_codepoint codepoints, which must
+ * be in increasing order.
+ *
+ * Since: REPLACEME
+ */
+HB_EXTERN void
+hb_set_add_sorted_array (hb_set_t             *set,
+		         const hb_codepoint_t *sorted_codepoints,
+		         unsigned int          num_codepoints)
+{
+  if (unlikely(!set || !sorted_codepoints || !num_codepoints)) return;
+
+  set->add_sorted_array (sorted_codepoints,
+		         num_codepoints,
+		         sizeof(hb_codepoint_t));
+}
+
 /**
  * hb_set_get_empty:
  *
diff --git a/src/hb-set.h b/src/hb-set.h
index 423225bf9..19374e022 100644
--- a/src/hb-set.h
+++ b/src/hb-set.h
@@ -60,6 +60,11 @@ typedef struct hb_set_t hb_set_t;
 HB_EXTERN hb_set_t *
 hb_set_create (void);
 
+HB_EXTERN void
+hb_set_add_sorted_array (hb_set_t             *set,
+		         const hb_codepoint_t *sorted_codepoints,
+		         unsigned int          num_codepoints);
+
 HB_EXTERN hb_set_t *
 hb_set_get_empty (void);
 
diff --git a/test/api/test-set.c b/test/api/test-set.c
index f2f9419bc..4ac95d9bb 100644
--- a/test/api/test-set.c
+++ b/test/api/test-set.c
@@ -1067,6 +1067,23 @@ test_set_inverted_operations (void)
   g_assert (all_succeeded);
 }
 
+static void
+test_hb_set_add_sorted_array (void)
+{
+  hb_set_t *set = hb_set_create ();
+  hb_codepoint_t array[7] = {1, 2, 3, 1000, 2000, 2001, 2002};
+  hb_set_add_sorted_array (set, array, 7);
+  g_assert_cmpint (hb_set_get_population (set), ==, 7);
+  g_assert (hb_set_has (set, 1));
+  g_assert (hb_set_has (set, 2));
+  g_assert (hb_set_has (set, 3));
+  g_assert (hb_set_has (set, 1000));
+  g_assert (hb_set_has (set, 2000));
+  g_assert (hb_set_has (set, 2001));
+  g_assert (hb_set_has (set, 2002));
+  hb_set_destroy (set);
+}
+
 int
 main (int argc, char **argv)
 {
@@ -1090,5 +1107,7 @@ main (int argc, char **argv)
   hb_test_add (test_set_inverted_equality);
   hb_test_add (test_set_inverted_operations);
 
+  hb_test_add (test_hb_set_add_sorted_array);
+
   return hb_test_run();
 }