380 lines
9.1 KiB
C
380 lines
9.1 KiB
C
|
/* SPDX-License-Identifier: BSD-3-Clause
|
||
|
* Copyright(c) 2010-2015 Intel Corporation.
|
||
|
*/
|
||
|
|
||
|
#ifndef _RTE_JHASH_H
|
||
|
#define _RTE_JHASH_H
|
||
|
|
||
|
/**
|
||
|
* @file
|
||
|
*
|
||
|
* jhash functions.
|
||
|
*/
|
||
|
|
||
|
#ifdef __cplusplus
|
||
|
extern "C" {
|
||
|
#endif
|
||
|
|
||
|
//#include <rte_byteorder.h>
|
||
|
|
||
|
/* jhash.h: Jenkins hash support.
|
||
|
*
|
||
|
* Copyright (C) 2006 Bob Jenkins (bob_jenkins@burtleburtle.net)
|
||
|
*
|
||
|
* http://burtleburtle.net/bob/hash/
|
||
|
*
|
||
|
* These are the credits from Bob's sources:
|
||
|
*
|
||
|
* lookup3.c, by Bob Jenkins, May 2006, Public Domain.
|
||
|
*
|
||
|
* These are functions for producing 32-bit hashes for hash table lookup.
|
||
|
* hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final()
|
||
|
* are externally useful functions. Routines to test the hash are included
|
||
|
* if SELF_TEST is defined. You can use this free for any purpose. It's in
|
||
|
* the public domain. It has no warranty.
|
||
|
*
|
||
|
* $FreeBSD$
|
||
|
*/
|
||
|
|
||
|
#define rot(x, k) (((x) << (k)) | ((x) >> (32-(k))))
|
||
|
|
||
|
/** @internal Internal function. NOTE: Arguments are modified. */
|
||
|
#define __rte_jhash_mix(a, b, c) do { \
|
||
|
a -= c; a ^= rot(c, 4); c += b; \
|
||
|
b -= a; b ^= rot(a, 6); a += c; \
|
||
|
c -= b; c ^= rot(b, 8); b += a; \
|
||
|
a -= c; a ^= rot(c, 16); c += b; \
|
||
|
b -= a; b ^= rot(a, 19); a += c; \
|
||
|
c -= b; c ^= rot(b, 4); b += a; \
|
||
|
} while (0)
|
||
|
|
||
|
#define __rte_jhash_final(a, b, c) do { \
|
||
|
c ^= b; c -= rot(b, 14); \
|
||
|
a ^= c; a -= rot(c, 11); \
|
||
|
b ^= a; b -= rot(a, 25); \
|
||
|
c ^= b; c -= rot(b, 16); \
|
||
|
a ^= c; a -= rot(c, 4); \
|
||
|
b ^= a; b -= rot(a, 14); \
|
||
|
c ^= b; c -= rot(b, 24); \
|
||
|
} while (0)
|
||
|
|
||
|
/** The golden ratio: an arbitrary value. */
|
||
|
#define RTE_JHASH_GOLDEN_RATIO 0xdeadbeef
|
||
|
|
||
|
#if RTE_BYTE_ORDER == RTE_LITTLE_ENDIAN
|
||
|
#define BIT_SHIFT(x, y, k) (((x) >> (k)) | ((uint64_t)(y) << (32-(k))))
|
||
|
#else
|
||
|
#define BIT_SHIFT(x, y, k) (((uint64_t)(x) << (k)) | ((y) >> (32-(k))))
|
||
|
#endif
|
||
|
|
||
|
#define LOWER8b_MASK rte_le_to_cpu_32(0xff)
|
||
|
#define LOWER16b_MASK rte_le_to_cpu_32(0xffff)
|
||
|
#define LOWER24b_MASK rte_le_to_cpu_32(0xffffff)
|
||
|
|
||
|
static inline void
|
||
|
__rte_jhash_2hashes(const void *key, uint32_t length, uint32_t *pc,
|
||
|
uint32_t *pb, unsigned check_align)
|
||
|
{
|
||
|
uint32_t a, b, c;
|
||
|
|
||
|
/* Set up the internal state */
|
||
|
a = b = c = RTE_JHASH_GOLDEN_RATIO + ((uint32_t)length) + *pc;
|
||
|
c += *pb;
|
||
|
|
||
|
/*
|
||
|
* Check key alignment. For x86 architecture, first case is always optimal
|
||
|
* If check_align is not set, first case will be used
|
||
|
*/
|
||
|
#if defined(RTE_ARCH_X86_64) || defined(RTE_ARCH_I686) || defined(RTE_ARCH_X86_X32)
|
||
|
const uint32_t *k = (const uint32_t *)key;
|
||
|
const uint32_t s = 0;
|
||
|
#else
|
||
|
const uint32_t *k = (uint32_t *)((uintptr_t)key & (uintptr_t)~3);
|
||
|
const uint32_t s = ((uintptr_t)key & 3) * CHAR_BIT;
|
||
|
#endif
|
||
|
if (!check_align || s == 0) {
|
||
|
while (length > 12) {
|
||
|
a += k[0];
|
||
|
b += k[1];
|
||
|
c += k[2];
|
||
|
|
||
|
__rte_jhash_mix(a, b, c);
|
||
|
|
||
|
k += 3;
|
||
|
length -= 12;
|
||
|
}
|
||
|
|
||
|
switch (length) {
|
||
|
case 12:
|
||
|
c += k[2]; b += k[1]; a += k[0]; break;
|
||
|
case 11:
|
||
|
c += k[2] & LOWER24b_MASK; b += k[1]; a += k[0]; break;
|
||
|
case 10:
|
||
|
c += k[2] & LOWER16b_MASK; b += k[1]; a += k[0]; break;
|
||
|
case 9:
|
||
|
c += k[2] & LOWER8b_MASK; b += k[1]; a += k[0]; break;
|
||
|
case 8:
|
||
|
b += k[1]; a += k[0]; break;
|
||
|
case 7:
|
||
|
b += k[1] & LOWER24b_MASK; a += k[0]; break;
|
||
|
case 6:
|
||
|
b += k[1] & LOWER16b_MASK; a += k[0]; break;
|
||
|
case 5:
|
||
|
b += k[1] & LOWER8b_MASK; a += k[0]; break;
|
||
|
case 4:
|
||
|
a += k[0]; break;
|
||
|
case 3:
|
||
|
a += k[0] & LOWER24b_MASK; break;
|
||
|
case 2:
|
||
|
a += k[0] & LOWER16b_MASK; break;
|
||
|
case 1:
|
||
|
a += k[0] & LOWER8b_MASK; break;
|
||
|
/* zero length strings require no mixing */
|
||
|
case 0:
|
||
|
*pc = c;
|
||
|
*pb = b;
|
||
|
return;
|
||
|
};
|
||
|
} else {
|
||
|
/* all but the last block: affect some 32 bits of (a, b, c) */
|
||
|
while (length > 12) {
|
||
|
a += BIT_SHIFT(k[0], k[1], s);
|
||
|
b += BIT_SHIFT(k[1], k[2], s);
|
||
|
c += BIT_SHIFT(k[2], k[3], s);
|
||
|
__rte_jhash_mix(a, b, c);
|
||
|
|
||
|
k += 3;
|
||
|
length -= 12;
|
||
|
}
|
||
|
|
||
|
/* last block: affect all 32 bits of (c) */
|
||
|
switch (length) {
|
||
|
case 12:
|
||
|
a += BIT_SHIFT(k[0], k[1], s);
|
||
|
b += BIT_SHIFT(k[1], k[2], s);
|
||
|
c += BIT_SHIFT(k[2], k[3], s);
|
||
|
break;
|
||
|
case 11:
|
||
|
a += BIT_SHIFT(k[0], k[1], s);
|
||
|
b += BIT_SHIFT(k[1], k[2], s);
|
||
|
c += BIT_SHIFT(k[2], k[3], s) & LOWER24b_MASK;
|
||
|
break;
|
||
|
case 10:
|
||
|
a += BIT_SHIFT(k[0], k[1], s);
|
||
|
b += BIT_SHIFT(k[1], k[2], s);
|
||
|
c += BIT_SHIFT(k[2], k[3], s) & LOWER16b_MASK;
|
||
|
break;
|
||
|
case 9:
|
||
|
a += BIT_SHIFT(k[0], k[1], s);
|
||
|
b += BIT_SHIFT(k[1], k[2], s);
|
||
|
c += BIT_SHIFT(k[2], k[3], s) & LOWER8b_MASK;
|
||
|
break;
|
||
|
case 8:
|
||
|
a += BIT_SHIFT(k[0], k[1], s);
|
||
|
b += BIT_SHIFT(k[1], k[2], s);
|
||
|
break;
|
||
|
case 7:
|
||
|
a += BIT_SHIFT(k[0], k[1], s);
|
||
|
b += BIT_SHIFT(k[1], k[2], s) & LOWER24b_MASK;
|
||
|
break;
|
||
|
case 6:
|
||
|
a += BIT_SHIFT(k[0], k[1], s);
|
||
|
b += BIT_SHIFT(k[1], k[2], s) & LOWER16b_MASK;
|
||
|
break;
|
||
|
case 5:
|
||
|
a += BIT_SHIFT(k[0], k[1], s);
|
||
|
b += BIT_SHIFT(k[1], k[2], s) & LOWER8b_MASK;
|
||
|
break;
|
||
|
case 4:
|
||
|
a += BIT_SHIFT(k[0], k[1], s);
|
||
|
break;
|
||
|
case 3:
|
||
|
a += BIT_SHIFT(k[0], k[1], s) & LOWER24b_MASK;
|
||
|
break;
|
||
|
case 2:
|
||
|
a += BIT_SHIFT(k[0], k[1], s) & LOWER16b_MASK;
|
||
|
break;
|
||
|
case 1:
|
||
|
a += BIT_SHIFT(k[0], k[1], s) & LOWER8b_MASK;
|
||
|
break;
|
||
|
/* zero length strings require no mixing */
|
||
|
case 0:
|
||
|
*pc = c;
|
||
|
*pb = b;
|
||
|
return;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
__rte_jhash_final(a, b, c);
|
||
|
|
||
|
*pc = c;
|
||
|
*pb = b;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Same as rte_jhash, but takes two seeds and return two uint32_ts.
|
||
|
* pc and pb must be non-null, and *pc and *pb must both be initialized
|
||
|
* with seeds. If you pass in (*pb)=0, the output (*pc) will be
|
||
|
* the same as the return value from rte_jhash.
|
||
|
*
|
||
|
* @param key
|
||
|
* Key to calculate hash of.
|
||
|
* @param length
|
||
|
* Length of key in bytes.
|
||
|
* @param pc
|
||
|
* IN: seed OUT: primary hash value.
|
||
|
* @param pb
|
||
|
* IN: second seed OUT: secondary hash value.
|
||
|
*/
|
||
|
static inline void
|
||
|
rte_jhash_2hashes(const void *key, uint32_t length, uint32_t *pc, uint32_t *pb)
|
||
|
{
|
||
|
__rte_jhash_2hashes(key, length, pc, pb, 1);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Same as rte_jhash_32b, but takes two seeds and return two uint32_ts.
|
||
|
* pc and pb must be non-null, and *pc and *pb must both be initialized
|
||
|
* with seeds. If you pass in (*pb)=0, the output (*pc) will be
|
||
|
* the same as the return value from rte_jhash_32b.
|
||
|
*
|
||
|
* @param k
|
||
|
* Key to calculate hash of.
|
||
|
* @param length
|
||
|
* Length of key in units of 4 bytes.
|
||
|
* @param pc
|
||
|
* IN: seed OUT: primary hash value.
|
||
|
* @param pb
|
||
|
* IN: second seed OUT: secondary hash value.
|
||
|
*/
|
||
|
static inline void
|
||
|
rte_jhash_32b_2hashes(const uint32_t *k, uint32_t length, uint32_t *pc, uint32_t *pb)
|
||
|
{
|
||
|
__rte_jhash_2hashes((const void *) k, (length << 2), pc, pb, 0);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* The most generic version, hashes an arbitrary sequence
|
||
|
* of bytes. No alignment or length assumptions are made about
|
||
|
* the input key. For keys not aligned to four byte boundaries
|
||
|
* or a multiple of four bytes in length, the memory region
|
||
|
* just after may be read (but not used in the computation).
|
||
|
* This may cross a page boundary.
|
||
|
*
|
||
|
* @param key
|
||
|
* Key to calculate hash of.
|
||
|
* @param length
|
||
|
* Length of key in bytes.
|
||
|
* @param initval
|
||
|
* Initialising value of hash.
|
||
|
* @return
|
||
|
* Calculated hash value.
|
||
|
*/
|
||
|
static inline uint32_t
|
||
|
rte_jhash(const void *key, uint32_t length, uint32_t initval)
|
||
|
{
|
||
|
uint32_t initval2 = 0;
|
||
|
|
||
|
rte_jhash_2hashes(key, length, &initval, &initval2);
|
||
|
|
||
|
return initval;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* A special optimized version that handles 1 or more of uint32_ts.
|
||
|
* The length parameter here is the number of uint32_ts in the key.
|
||
|
*
|
||
|
* @param k
|
||
|
* Key to calculate hash of.
|
||
|
* @param length
|
||
|
* Length of key in units of 4 bytes.
|
||
|
* @param initval
|
||
|
* Initialising value of hash.
|
||
|
* @return
|
||
|
* Calculated hash value.
|
||
|
*/
|
||
|
static inline uint32_t
|
||
|
rte_jhash_32b(const uint32_t *k, uint32_t length, uint32_t initval)
|
||
|
{
|
||
|
uint32_t initval2 = 0;
|
||
|
|
||
|
rte_jhash_32b_2hashes(k, length, &initval, &initval2);
|
||
|
|
||
|
return initval;
|
||
|
}
|
||
|
|
||
|
static inline uint32_t
|
||
|
__rte_jhash_3words(uint32_t a, uint32_t b, uint32_t c, uint32_t initval)
|
||
|
{
|
||
|
a += RTE_JHASH_GOLDEN_RATIO + initval;
|
||
|
b += RTE_JHASH_GOLDEN_RATIO + initval;
|
||
|
c += RTE_JHASH_GOLDEN_RATIO + initval;
|
||
|
|
||
|
__rte_jhash_final(a, b, c);
|
||
|
|
||
|
return c;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* A special ultra-optimized versions that knows it is hashing exactly
|
||
|
* 3 words.
|
||
|
*
|
||
|
* @param a
|
||
|
* First word to calculate hash of.
|
||
|
* @param b
|
||
|
* Second word to calculate hash of.
|
||
|
* @param c
|
||
|
* Third word to calculate hash of.
|
||
|
* @param initval
|
||
|
* Initialising value of hash.
|
||
|
* @return
|
||
|
* Calculated hash value.
|
||
|
*/
|
||
|
static inline uint32_t
|
||
|
rte_jhash_3words(uint32_t a, uint32_t b, uint32_t c, uint32_t initval)
|
||
|
{
|
||
|
return __rte_jhash_3words(a + 12, b + 12, c + 12, initval);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* A special ultra-optimized versions that knows it is hashing exactly
|
||
|
* 2 words.
|
||
|
*
|
||
|
* @param a
|
||
|
* First word to calculate hash of.
|
||
|
* @param b
|
||
|
* Second word to calculate hash of.
|
||
|
* @param initval
|
||
|
* Initialising value of hash.
|
||
|
* @return
|
||
|
* Calculated hash value.
|
||
|
*/
|
||
|
static inline uint32_t
|
||
|
rte_jhash_2words(uint32_t a, uint32_t b, uint32_t initval)
|
||
|
{
|
||
|
return __rte_jhash_3words(a + 8, b + 8, 8, initval);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* A special ultra-optimized versions that knows it is hashing exactly
|
||
|
* 1 word.
|
||
|
*
|
||
|
* @param a
|
||
|
* Word to calculate hash of.
|
||
|
* @param initval
|
||
|
* Initialising value of hash.
|
||
|
* @return
|
||
|
* Calculated hash value.
|
||
|
*/
|
||
|
static inline uint32_t
|
||
|
rte_jhash_1word(uint32_t a, uint32_t initval)
|
||
|
{
|
||
|
return __rte_jhash_3words(a + 4, 4, 4, initval);
|
||
|
}
|
||
|
|
||
|
#ifdef __cplusplus
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
#endif /* _RTE_JHASH_H */
|