#ifndef STADTX_HASH_H
#define STADTX_HASH_H
#ifndef DEBUG_STADTX_HASH
#define DEBUG_STADTX_HASH 0
#endif
#ifndef PERL_SEEN_HV_FUNC_H
#if !defined(U64)
#include <stdint.h>
#define U64 uint64_t
#endif
#if !defined(U32)
#define U32 uint32_t
#endif
#if !defined(U8)
#define U8 unsigned char
#endif
#if !defined(U16)
#define U16 uint16_t
#endif
#ifndef STRLEN
#define STRLEN int
#endif
#endif
#ifndef STADTX_STATIC_INLINE
#ifdef PERL_STATIC_INLINE
#define STADTX_STATIC_INLINE PERL_STATIC_INLINE
#else
#define STADTX_STATIC_INLINE static inline
#endif
#endif
#ifndef STMT_START
#define STMT_START do
#define STMT_END while(0)
#endif
#ifndef STADTX_ALLOW_UNALIGNED_AND_LITTLE_ENDIAN
/* STADTX_ALLOW_UNALIGNED_AND_LITTLE_ENDIAN only matters if nothing has defined U8TO64_LE etc,
* and when built with Perl these should be defined before this file is loaded.
*/
#ifdef U32_ALIGNMENT_REQUIRED
#define STADTX_ALLOW_UNALIGNED_AND_LITTLE_ENDIAN 0
#else
#define STADTX_ALLOW_UNALIGNED_AND_LITTLE_ENDIAN 1
#endif
#endif
#ifndef U8TO64_LE
#if STADTX_ALLOW_UNALIGNED_AND_LITTLE_ENDIAN
#define U8TO64_LE(ptr) (*((const U64 *)(ptr)))
#else
#define U8TO64_LE(ptr) (\
(U64)(ptr)[7] << 56 | \
(U64)(ptr)[6] << 48 | \
(U64)(ptr)[5] << 40 | \
(U64)(ptr)[4] << 32 | \
(U64)(ptr)[3] << 24 | \
(U64)(ptr)[2] << 16 | \
(U64)(ptr)[1] << 8 | \
(U64)(ptr)[0] \
)
#endif
#endif
#ifndef U8TO32_LE
#if STADTX_ALLOW_UNALIGNED_AND_LITTLE_ENDIAN
#define U8TO32_LE(ptr) (*((const U32 *)(ptr)))
#else
#define U8TO32_LE(ptr) (\
(U32)(ptr)[3] << 24 | \
(U32)(ptr)[2] << 16 | \
(U32)(ptr)[1] << 8 | \
(U32)(ptr)[0] \
)
#endif
#endif
#ifndef U8TO16_LE
#if STADTX_ALLOW_UNALIGNED_AND_LITTLE_ENDIAN
#define U8TO16_LE(ptr) (*((const U16 *)(ptr)))
#else
#define U8TO16_LE(ptr) (\
(U16)(ptr)[1] << 8 | \
(U16)(ptr)[0] \
)
#endif
#endif
/* Find best way to ROTL32/ROTL64 */
#if defined(_MSC_VER)
#include <stdlib.h> /* Microsoft put _rotl declaration in here */
#define ROTL32(x,r) _rotl(x,r)
#define ROTR32(x,r) _rotr(x,r)
#define ROTL64(x,r) _rotl64(x,r)
#define ROTR64(x,r) _rotr64(x,r)
#else
/* gcc recognises this code and generates a rotate instruction for CPUs with one */
#define ROTL32(x,r) (((U32)(x) << (r)) | ((U32)(x) >> (32 - (r))))
#define ROTR32(x,r) (((U32)(x) << (32 - (r))) | ((U32)(x) >> (r)))
#define ROTL64(x,r) ( ( (U64)(x) << (r) ) | ( (U64)(x) >> ( 64 - (r) ) ) )
#define ROTR64(x,r) ( ( (U64)(x) << ( 64 - (r) ) ) | ( (U64)(x) >> (r) ) )
#endif
/* do a marsaglia xor-shift permutation followed by a
* multiply by a prime (presumably large) and another
* marsaglia xor-shift permutation.
* One of these thoroughly changes the bits of the input.
* Two of these with different primes passes the Strict Avalanche Criteria
* in all the tests I did.
*
* Note that v cannot end up zero after a scramble64 unless it
* was zero in the first place.
*/
#define STADTX_SCRAMBLE64(v,prime) STMT_START { \
v ^= (v >> 13); \
v ^= (v << 35); \
v ^= (v >> 30); \
v *= prime; \
v ^= (v >> 19); \
v ^= (v << 15); \
v ^= (v >> 46); \
} STMT_END
STADTX_STATIC_INLINE void stadtx_seed_state (
const U8 *seed_ch,
U8 *state_ch
) {
const U64 *seed= (const U64 *)seed_ch;
U64 *state= (U64 *)state_ch;
/* first we apply two masks to each word of the seed, this means that
* a) at least one of state[0] and state[2] is nonzero,
* b) at least one of state[1] and state[3] is nonzero
* c) that state[0] and state[2] are different
* d) that state[1] and state[3] are different
* e) that the replacement value for any zero's is a totally different from the seed value.
* (iow, if seed[0] is 0x43f6a8885a308d31UL then state[0] becomes 0, which is the replaced
* with 1, which is totally different.). */
/* hex expansion of pi, skipping first two digits. pi= 3.2[43f6...]*/
/* pi value in hex from here:
* http://turner.faculty.swau.edu/mathematics/materialslibrary/pi/pibases.html*/
state[0]= seed[0] ^ UINT64_C(0x43f6a8885a308d31);
state[1]= seed[1] ^ UINT64_C(0x3198a2e03707344a);
state[2]= seed[0] ^ UINT64_C(0x4093822299f31d00);
state[3]= seed[1] ^ UINT64_C(0x82efa98ec4e6c894);
if (!state[0]) state[0]=1;
if (!state[1]) state[1]=2;
if (!state[2]) state[2]=4;
if (!state[3]) state[3]=8;
/* and now for good measure we double scramble all four -
* a double scramble guarantees a complete avalanche of all the
* bits in the seed - IOW, by the time we are hashing the
* four state vectors should be completely different and utterly
* uncognizable from the input seed bits */
STADTX_SCRAMBLE64(state[0],UINT64_C(0x801178846e899d17));
STADTX_SCRAMBLE64(state[0],UINT64_C(0xdd51e5d1c9a5a151));
STADTX_SCRAMBLE64(state[1],UINT64_C(0x93a7d6c8c62e4835));
STADTX_SCRAMBLE64(state[1],UINT64_C(0x803340f36895c2b5));
STADTX_SCRAMBLE64(state[2],UINT64_C(0xbea9344eb7565eeb));
STADTX_SCRAMBLE64(state[2],UINT64_C(0xcd95d1e509b995cd));
STADTX_SCRAMBLE64(state[3],UINT64_C(0x9999791977e30c13));
STADTX_SCRAMBLE64(state[3],UINT64_C(0xaab8b6b05abfc6cd));
}
#define STADTX_K0_U64 UINT64_C(0xb89b0f8e1655514f)
#define STADTX_K1_U64 UINT64_C(0x8c6f736011bd5127)
#define STADTX_K2_U64 UINT64_C(0x8f29bd94edce7b39)
#define STADTX_K3_U64 UINT64_C(0x9c1b8e1e9628323f)
#define STADTX_K2_U32 0x802910e3
#define STADTX_K3_U32 0x819b13af
#define STADTX_K4_U32 0x91cb27e5
#define STADTX_K5_U32 0xc1a269c1
STADTX_STATIC_INLINE U64 stadtx_hash_with_state(
const U8 *state_ch,
const U8 *key,
const STRLEN key_len
) {
U64 *state= (U64 *)state_ch;
STRLEN len = key_len;
U64 v0= state[0] ^ ((key_len+1) * STADTX_K0_U64);
U64 v1= state[1] ^ ((key_len+2) * STADTX_K1_U64);
if (len < 32) {
switch(len >> 3) {
case 3:
v0 += U8TO64_LE(key) * STADTX_K3_U64;
v0= ROTR64(v0, 17) ^ v1;
v1= ROTR64(v1, 53) + v0;
key += 8;
/* FALLTHROUGH */
case 2:
v0 += U8TO64_LE(key) * STADTX_K3_U64;
v0= ROTR64(v0, 17) ^ v1;
v1= ROTR64(v1, 53) + v0;
key += 8;
/* FALLTHROUGH */
case 1:
v0 += U8TO64_LE(key) * STADTX_K3_U64;
v0= ROTR64(v0, 17) ^ v1;
v1= ROTR64(v1, 53) + v0;
key += 8;
/* FALLTHROUGH */
case 0:
default: break;
}
switch ( len & 0x7 ) {
case 7: v0 += (U64)key[6] << 32;
/* FALLTHROUGH */
case 6: v1 += (U64)key[5] << 48;
/* FALLTHROUGH */
case 5: v0 += (U64)key[4] << 16;
/* FALLTHROUGH */
case 4: v1 += (U64)U8TO32_LE(key);
break;
case 3: v0 += (U64)key[2] << 48;
/* FALLTHROUGH */
case 2: v1 += (U64)U8TO16_LE(key);
break;
case 1: v0 += (U64)key[0];
/* FALLTHROUGH */
case 0: v1 = ROTL64(v1, 32) ^ 0xFF;
break;
}
v1 ^= v0;
v0 = ROTR64(v0,33) + v1;
v1 = ROTL64(v1,17) ^ v0;
v0 = ROTL64(v0,43) + v1;
v1 = ROTL64(v1,31) - v0;
v0 = ROTL64(v0,13) ^ v1;
v1 -= v0;
v0 = ROTL64(v0,41) + v1;
v1 = ROTL64(v1,37) ^ v0;
v0 = ROTR64(v0,39) + v1;
v1 = ROTR64(v1,15) + v0;
v0 = ROTL64(v0,15) ^ v1;
v1 = ROTR64(v1, 5);
return v0 ^ v1;
} else {
U64 v2= state[2] ^ ((key_len+3) * STADTX_K2_U64);
U64 v3= state[3] ^ ((key_len+4) * STADTX_K3_U64);
do {
v0 += (U64)U8TO64_LE(key+ 0) * STADTX_K2_U32; v0= ROTL64(v0,57) ^ v3;
v1 += (U64)U8TO64_LE(key+ 8) * STADTX_K3_U32; v1= ROTL64(v1,63) ^ v2;
v2 += (U64)U8TO64_LE(key+16) * STADTX_K4_U32; v2= ROTR64(v2,47) + v0;
v3 += (U64)U8TO64_LE(key+24) * STADTX_K5_U32; v3= ROTR64(v3,11) - v1;
key += 32;
len -= 32;
} while ( len >= 32 );
switch ( len >> 3 ) {
case 3: v0 += ((U64)U8TO64_LE(key) * STADTX_K2_U32); key += 8; v0= ROTL64(v0,57) ^ v3;
/* FALLTHROUGH */
case 2: v1 += ((U64)U8TO64_LE(key) * STADTX_K3_U32); key += 8; v1= ROTL64(v1,63) ^ v2;
/* FALLTHROUGH */
case 1: v2 += ((U64)U8TO64_LE(key) * STADTX_K4_U32); key += 8; v2= ROTR64(v2,47) + v0;
/* FALLTHROUGH */
case 0: v3 = ROTR64(v3,11) - v1;
/* FALLTHROUGH */
}
v0 ^= (len+1) * STADTX_K3_U64;
switch ( len & 0x7 ) {
case 7: v1 += (U64)key[6];
/* FALLTHROUGH */
case 6: v2 += (U64)U8TO16_LE(key+4);
v3 += (U64)U8TO32_LE(key);
break;
case 5: v1 += (U64)key[4];
/* FALLTHROUGH */
case 4: v2 += (U64)U8TO32_LE(key);
break;
case 3: v3 += (U64)key[2];
/* FALLTHROUGH */
case 2: v1 += (U64)U8TO16_LE(key);
break;
case 1: v2 += (U64)key[0];
/* FALLTHROUGH */
case 0: v3 = ROTL64(v3, 32) ^ 0xFF;
break;
}
v1 -= v2;
v0 = ROTR64(v0,19);
v1 -= v0;
v1 = ROTR64(v1,53);
v3 ^= v1;
v0 -= v3;
v3 = ROTL64(v3,43);
v0 += v3;
v0 = ROTR64(v0, 3);
v3 -= v0;
v2 = ROTR64(v2,43) - v3;
v2 = ROTL64(v2,55) ^ v0;
v1 -= v2;
v3 = ROTR64(v3, 7) - v2;
v2 = ROTR64(v2,31);
v3 += v2;
v2 -= v1;
v3 = ROTR64(v3,39);
v2 ^= v3;
v3 = ROTR64(v3,17) ^ v2;
v1 += v3;
v1 = ROTR64(v1, 9);
v2 ^= v1;
v2 = ROTL64(v2,24);
v3 ^= v2;
v3 = ROTR64(v3,59);
v0 = ROTR64(v0, 1) - v1;
return v0 ^ v1 ^ v2 ^ v3;
}
}
STADTX_STATIC_INLINE U64 stadtx_hash(
const U8 *seed_ch,
const U8 *key,
const STRLEN key_len
) {
U64 state[4];
stadtx_seed_state(seed_ch,(U8*)state);
return stadtx_hash_with_state((U8*)state,key,key_len);
}
#endif