X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fhash.h;h=109612fb760fe4d93e21c7ad091b41fd29b2f764;hb=f9ef1c31cfcd2d9ded66588a11c59e29e5aaa2ca;hp=3f140381c36104ce22eb558e08a9ea75ab52d6a4;hpb=44528c546359a95c57e8a0e4b3703c5086b15f24;p=openvswitch

diff --git a/lib/hash.h b/lib/hash.h
index 3f140381..109612fb 100644
--- a/lib/hash.h
+++ b/lib/hash.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -49,7 +49,8 @@
     } while (0)
 
 uint32_t hash_words(const uint32_t *, size_t n_word, uint32_t basis);
-uint32_t hash_2words(const uint32_t *, uint32_t basis);
+uint32_t hash_2words(uint32_t, uint32_t);
+uint32_t hash_3words(uint32_t, uint32_t, uint32_t);
 uint32_t hash_bytes(const void *, size_t n_bytes, uint32_t basis);
 
 static inline uint32_t hash_string(const char *s, uint32_t basis)
@@ -58,7 +59,11 @@ static inline uint32_t hash_string(const char *s, uint32_t basis)
 }
 
 /* This is Bob Jenkins' integer hash from
- * http://burtleburtle.net/bob/hash/integer.html, modified for style. */
+ * http://burtleburtle.net/bob/hash/integer.html, modified for style.
+ *
+ * This hash is faster than hash_2words(), but it isn't as good when 'basis' is
+ * important.  So use this function for speed or hash_2words() for hash
+ * quality. */
 static inline uint32_t hash_int(uint32_t x, uint32_t basis)
 {
     x -= x << 6;
@@ -83,8 +88,11 @@ static inline uint32_t hash_boolean(bool x, uint32_t basis)
 
 static inline uint32_t hash_double(double x, uint32_t basis)
 {
-    BUILD_ASSERT_DECL(sizeof x == 8);
-    return hash_2words((const uint32_t *) &x, basis);
+    uint32_t value[2];
+    BUILD_ASSERT_DECL(sizeof x == sizeof value);
+
+    memcpy(value, &x, sizeof value);
+    return hash_3words(value[0], value[1], basis);
 }
 
 static inline uint32_t hash_pointer(const void *p, uint32_t basis)