From 02e5e583688999c4dc04f11b3924da65f99af7e3 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Tue, 16 Apr 2013 23:13:10 -0400
Subject: [PATCH] Speed up Speed up hb_set_digest_common_bits_t calcs

Correctly this time.
---
 src/hb-set-private.hh | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/hb-set-private.hh b/src/hb-set-private.hh
index d9e0d29..8f741b0 100644
--- a/src/hb-set-private.hh
+++ b/src/hb-set-private.hh
@@ -54,9 +54,11 @@ struct hb_set_digest_common_bits_t
   }
 
   inline void add_range (hb_codepoint_t a, hb_codepoint_t b) {
-    /* TODO Speedup. */
-    for (unsigned int i = a; i < b + 1; i++)
-      add (i);
+    add (a);
+    /* The negation here stands for ~(x-1). */
+    mask_t upper_bits = -(1 << _hb_bit_storage (a ^ b));
+    mask &= upper_bits;
+    value &= upper_bits;
   }
 
   inline bool may_have (hb_codepoint_t g) const {
-- 
2.7.4