From b2a52eedaa406bacfa53d2b2a3d4236e46042bcd Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Fri, 14 Dec 2012 13:43:54 -0800 Subject: [PATCH] hash: Correct implementation of mhash_finish(). With rotates instead of shifts, the upper and lower 16 bits of the returned hash are always the same. I noticed this while working on replacing Jenkins hash by murmurhash, because some of the database unit tests started failing, e.g. "row hashing (scalars)". Signed-off-by: Ben Pfaff Acked-by: Ethan Jackson --- lib/hash.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/lib/hash.h b/lib/hash.h index 701e6866e..96866c42a 100644 --- a/lib/hash.h +++ b/lib/hash.h @@ -152,11 +152,11 @@ static inline uint32_t mhash_add(uint32_t hash, uint32_t data) static inline uint32_t mhash_finish(uint32_t hash, size_t n) { hash ^= n * 4; - hash ^= hash_rot(hash, 16); + hash ^= hash >> 16; hash *= 0x85ebca6b; - hash ^= hash_rot(hash, 13); + hash ^= hash >> 13; hash *= 0xc2b2ae35; - hash ^= hash_rot(hash, 16); + hash ^= hash >> 16; return hash; } -- 2.43.0