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SipHash x86 optimizations.

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This commit is contained in:
antirez 2017-02-20 17:32:46 +01:00
parent adeed29a99
commit 05ea8c6122
1 changed files with 23 additions and 2 deletions
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25
src/siphash.c
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@ -40,6 +40,13 @@
#include <string.h>
#include <ctype.h>
/* Test of the CPU is Little Endian and supports not aligned accesses.
* Two interesting conditions to speedup the function that happen to be
* in most of x86 servers. */
#if defined(__X86_64__) || defined(__x86_64__) || defined (__i386__)
#define UNALIGNED_LE_CPU
#endif
#define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))
#define U32TO8_LE(p, v) \
@ -52,11 +59,15 @@
U32TO8_LE((p), (uint32_t)((v))); \
U32TO8_LE((p) + 4, (uint32_t)((v) >> 32));
#ifdef UNALIGNED_LE_CPU
#define U8TO64_LE(p) (*((uint64_t*)(p)))
#else
#define U8TO64_LE(p) \
(((uint64_t)((p)[0])) | ((uint64_t)((p)[1]) << 8) | \
((uint64_t)((p)[2]) << 16) | ((uint64_t)((p)[3]) << 24) | \
((uint64_t)((p)[4]) << 32) | ((uint64_t)((p)[5]) << 40) | \
((uint64_t)((p)[6]) << 48) | ((uint64_t)((p)[7]) << 56))
#endif
#define U8TO64_LE_NOCASE(p) \
(((uint64_t)(tolower((p)[0]))) | \
@ -87,8 +98,10 @@
} while (0)
uint64_t siphash(const uint8_t *in, const size_t inlen, const uint8_t *k) {
#ifndef UNALIGNED_LE_CPU
uint64_t hash;
uint8_t *out = (uint8_t*) &hash;
#endif
uint64_t v0 = 0x736f6d6570736575ULL;
uint64_t v1 = 0x646f72616e646f6dULL;
uint64_t v2 = 0x6c7967656e657261ULL;
@ -139,15 +152,20 @@ uint64_t siphash(const uint8_t *in, const size_t inlen, const uint8_t *k) {
SIPROUND;
b = v0 ^ v1 ^ v2 ^ v3;
#ifndef UNALIGNED_LE_CPU
U64TO8_LE(out, b);
return hash;
#else
return b;
#endif
}
uint64_t siphash_nocase(const uint8_t *in, const size_t inlen, const uint8_t *k)
{
#ifndef UNALIGNED_LE_CPU
uint64_t hash;
uint8_t *out = (uint8_t*) &hash;
#endif
uint64_t v0 = 0x736f6d6570736575ULL;
uint64_t v1 = 0x646f72616e646f6dULL;
uint64_t v2 = 0x6c7967656e657261ULL;
@ -198,9 +216,12 @@ uint64_t siphash_nocase(const uint8_t *in, const size_t inlen, const uint8_t *k)
SIPROUND;
b = v0 ^ v1 ^ v2 ^ v3;
#ifndef UNALIGNED_LE_CPU
U64TO8_LE(out, b);
return hash;
#else
return b;
#endif
}