xxh32() - fast on both 32/64-bit platforms
xxh64() - fast only on 64-bit platform
Create xxhash() which will pickup fastest version
on compile time.
As result depends on cpu word size,
the main proporse of that - in memory hashing.
Changes:
v2:
- Create that patch
v3 -> v8:
- Nothing, whole patchset version bump
Signed-off-by: Timofey Titovets <nefelim4ag@xxxxxxxxx>
Reviewed-by: Pavel Tatashin <pavel.tatashin@xxxxxxxxxxxxx>
Reviewed-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
CC: Andrea Arcangeli <aarcange@xxxxxxxxxx>
CC: linux-mm@xxxxxxxxx
CC: kvm@xxxxxxxxxxxxxxx
CC: leesioh <solee@xxxxxxxxxxxxxx>
---
include/linux/xxhash.h | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/include/linux/xxhash.h b/include/linux/xxhash.h
index 9e1f42cb57e9..52b073fea17f 100644
--- a/include/linux/xxhash.h
+++ b/include/linux/xxhash.h
@@ -107,6 +107,29 @@ uint32_t xxh32(const void *input, size_t length, uint32_t seed);
*/
uint64_t xxh64(const void *input, size_t length, uint64_t seed);
+/**
+ * xxhash() - calculate wordsize hash of the input with a given seed
+ * @input: The data to hash.
+ * @length: The length of the data to hash.
+ * @seed: The seed can be used to alter the result predictably.
+ *
+ * If the hash does not need to be comparable between machines with
+ * different word sizes, this function will call whichever of xxh32()
+ * or xxh64() is faster.
+ *
+ * Return: wordsize hash of the data.
+ */
+
+static inline unsigned long xxhash(const void *input, size_t length,
+ uint64_t seed)
+{
+#if BITS_PER_LONG == 64
+ return xxh64(input, length, seed);
+#else
+ return xxh32(input, length, seed);
+#endif
+}
+
/*-****************************
* Streaming Hash Functions
*****************************/
--
2.19.0
