hash: Add hash_add64().

Add support for adding 64-bit words to hashes.  This will be used by
subsequent patches.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>

3 files changed, 27 insertions, 11 deletions

diff --git a/lib/classifier-private.h b/lib/classifier-private.h
index 2522e91fc..17eed2c9e 100644
--- a/lib/classifier-private.h
+++ b/lib/classifier-private.h
@@ -236,8 +236,7 @@ miniflow_hash(const struct miniflow *flow, uint32_t basis)
         }
         p++;
     }
-    hash = hash_add(hash, hash_map);
-    hash = hash_add(hash, hash_map >> 32);
+    hash = hash_add64(hash, hash_map);
 
     return hash_finish(hash, p - values);
 }
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 6158bf970..22a873385 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -1367,8 +1367,7 @@ netdev_flow_mask_init(struct netdev_flow_key *mask,
     mask->mf.values_inline = true;
     mask->mf.map = mask_map;
 
-    hash = hash_add(hash, mask_map);
-    hash = hash_add(hash, mask_map >> 32);
+    hash = hash_add64(hash, mask_map);
 
     n = dst - mask->mf.inline_values;
 
diff --git a/lib/hash.h b/lib/hash.h
index fe8d5a231..9253760b5 100644
--- a/lib/hash.h
+++ b/lib/hash.h
@@ -92,6 +92,11 @@ static inline uint32_t hash_add(uint32_t hash, uint32_t data)
     return mhash_add(hash, data);
 }
 
+static inline uint32_t hash_add64(uint32_t hash, uint64_t data)
+{
+    return hash_add(hash_add(hash, data), data >> 32);
+}
+
 static inline uint32_t hash_finish(uint32_t hash, uint32_t final)
 {
     return mhash_finish(hash ^ final);
@@ -118,7 +123,14 @@ hash_words_inline(const uint32_t p[], size_t n_words, uint32_t basis)
 static inline uint32_t
 hash_words64_inline(const uint64_t p[], size_t n_words, uint32_t basis)
 {
-    return hash_words_inline((uint32_t *)p, n_words * 2, basis);
+    uint32_t hash;
+    size_t i;
+
+    hash = basis;
+    for (i = 0; i < n_words; i++) {
+        hash = hash_add64(hash, p[i]);
+    }
+    return hash_finish(hash, n_words * 8);
 }
 
 static inline uint32_t hash_pointer(const void *p, uint32_t basis)
@@ -139,15 +151,15 @@ static inline uint32_t hash_2words(uint32_t x, uint32_t y)
     return hash_finish(hash_add(hash_add(x, 0), y), 8);
 }
 
-static inline uint32_t hash_uint64(const uint64_t x)
+static inline uint32_t hash_uint64_basis(const uint64_t x,
+                                         const uint32_t basis)
 {
-    return hash_2words((uint32_t)(x >> 32), (uint32_t)x);
+    return hash_finish(hash_add64(basis, x), 8);
 }
 
-static inline uint32_t hash_uint64_basis(const uint64_t x,
-                                         const uint32_t basis)
+static inline uint32_t hash_uint64(const uint64_t x)
 {
-    return hash_3words((uint32_t)(x >> 32), (uint32_t)x, basis);
+    return hash_uint64_basis(x, 0);
 }
 
 #else /* __SSE4_2__ && __x86_64__ */
@@ -158,6 +170,12 @@ static inline uint32_t hash_add(uint32_t hash, uint32_t data)
     return _mm_crc32_u32(hash, data);
 }
 
+/* Add the halves of 'data' in the memory order. */
+static inline uint32_t hash_add64(uint32_t hash, uint64_t data)
+{
+    return _mm_crc32_u64(hash, data);
+}
+
 static inline uint32_t hash_finish(uint64_t hash, uint64_t final)
 {
     /* The finishing multiplier 0x805204f3 has been experimentally
@@ -244,7 +262,7 @@ static inline uint32_t hash_uint64_basis(const uint64_t x,
                                          const uint32_t basis)
 {
     /* '23' chosen to mix bits enough for the test-hash to pass. */
-    return hash_finish(_mm_crc32_u64(basis, x), 23);
+    return hash_finish(hash_add64(basis, x), 23);
 }
 
 static inline uint32_t hash_uint64(const uint64_t x)