dict_hash_uint64: do not ignore upper 32 bits of the quantity

diff --git a/dict.c b/dict.c
index c9a449b..236e90e 100644 (file)
--- a/dict.c
+++ b/dict.c
@@ -1,6 +1,6 @@
 /*
  * This file is part of ltrace.
- * Copyright (C) 2012, 2013 Petr Machata, Red Hat Inc.
+ * Copyright (C) 2012, 2013, 2014 Petr Machata, Red Hat Inc.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -476,11 +476,9 @@ dict_eq_int(const int *key1, const int *key2)
 size_t
 dict_hash_uint64(const uint64_t *key)
 {
-       // I use the same hash function as for 32-bit signed integers. This
-       // probably will not have great performance for values that don't fit
-       // into a 32-bit signed int, but this will do for now
-       int key32 = (int)(*key);
-       return dict_hash_int(&key32);
+       int const a = (int) *key;
+       int const b = (int) (*key >> 32);
+       return dict_hash_int (&a) ^ dict_hash_int (&b);
 }
 
 int