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[perl5.git] / zaphod32_hash.h
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1#ifndef DEBUG_ZAPHOD32_HASH
2#define DEBUG_ZAPHOD32_HASH 0
3
4#if DEBUG_ZAPHOD32_HASH == 1
5#include <stdio.h>
6#define ZAPHOD32_WARN6(pat,v0,v1,v2,v3,v4,v5) printf(pat, v0, v1, v2, v3, v4, v5)
7#define ZAPHOD32_WARN5(pat,v0,v1,v2,v3,v4) printf(pat, v0, v1, v2, v3, v4)
8#define ZAPHOD32_WARN4(pat,v0,v1,v2,v3) printf(pat, v0, v1, v2, v3)
9#define ZAPHOD32_WARN3(pat,v0,v1,v2) printf(pat, v0, v1, v2)
10#define ZAPHOD32_WARN2(pat,v0,v1) printf(pat, v0, v1)
11#define NOTE3(pat,v0,v1,v2) printf(pat, v0, v1, v2)
12#elif DEBUG_ZAPHOD32_HASH == 2
13#define ZAPHOD32_WARN6(pat,v0,v1,v2,v3,v4,v5)
14#define ZAPHOD32_WARN5(pat,v0,v1,v2,v3,v4)
15#define ZAPHOD32_WARN4(pat,v0,v1,v2,v3)
16#define ZAPHOD32_WARN3(pat,v0,v1,v2)
17#define ZAPHOD32_WARN2(pat,v0,v1)
18#define NOTE3(pat,v0,v1,v2) printf(pat, v0, v1, v2)
19#else
20#define ZAPHOD32_WARN6(pat,v0,v1,v2,v3,v4,v5)
21#define ZAPHOD32_WARN5(pat,v0,v1,v2,v3,v4)
22#define ZAPHOD32_WARN4(pat,v0,v1,v2,v3)
23#define ZAPHOD32_WARN3(pat,v0,v1,v2)
24#define NOTE3(pat,v0,v1,v2)
25#define ZAPHOD32_WARN2(pat,v0,v1)
26#endif
27
d939098c 28/* Find best way to ROTL32/ROTL64 */
9d5e3f1a 29#ifndef ROTL32
d939098c 30#if defined(_MSC_VER)
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31#include <stdlib.h> /* Microsoft put _rotl declaration in here */
32#define ROTL32(x,r) _rotl(x,r)
33#define ROTR32(x,r) _rotr(x,r)
d939098c 34#else
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35/* gcc recognises this code and generates a rotate instruction for CPUs with one */
36#define ROTL32(x,r) (((U32)(x) << (r)) | ((U32)(x) >> (32 - (r))))
37#define ROTR32(x,r) (((U32)(x) << (32 - (r))) | ((U32)(x) >> (r)))
d939098c 38#endif
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39#endif
40
41#ifndef PERL_SEEN_HV_FUNC_H
42#if !defined(U64)
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43#include <stdint.h>
44#define U64 uint64_t
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45#endif
46
47#if !defined(U32)
f8a8fb6d 48#define U32 uint32_t
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49#endif
50
51#if !defined(U8)
f8a8fb6d 52#define U8 unsigned char
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53#endif
54
55#if !defined(U16)
f8a8fb6d 56#define U16 uint16_t
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57#endif
58
59#ifndef STRLEN
60#define STRLEN int
61#endif
62#endif
63
64#ifndef ZAPHOD32_STATIC_INLINE
65#ifdef PERL_STATIC_INLINE
66#define ZAPHOD32_STATIC_INLINE PERL_STATIC_INLINE
67#else
68#define ZAPHOD32_STATIC_INLINE static inline
69#endif
70#endif
71
72#ifndef STMT_START
73#define STMT_START do
74#define STMT_END while(0)
75#endif
76
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77/* This is two marsaglia xor-shift permutes, with a prime-multiple
78 * sandwiched inside. The end result of doing this twice with different
79 * primes is a completely avalanched v. */
80#define ZAPHOD32_SCRAMBLE32(v,prime) STMT_START { \
81 v ^= (v>>9); \
82 v ^= (v<<21); \
83 v ^= (v>>16); \
84 v *= prime; \
85 v ^= (v>>17); \
86 v ^= (v<<15); \
87 v ^= (v>>23); \
88} STMT_END
89
90#define ZAPHOD32_FINALIZE(v0,v1,v2) STMT_START { \
91 ZAPHOD32_WARN3("v0=%08x v1=%08x v2=%08x - ZAPHOD32 FINALIZE\n", \
92 (unsigned int)v0, (unsigned int)v1, (unsigned int)v2); \
93 v2 += v0; \
94 v1 -= v2; \
95 v1 = ROTL32(v1, 6); \
96 v2 ^= v1; \
97 v2 = ROTL32(v2, 28); \
98 v1 ^= v2; \
99 v0 += v1; \
100 v1 = ROTL32(v1, 24); \
101 v2 += v1; \
102 v2 = ROTL32(v2, 18) + v1; \
103 v0 ^= v2; \
104 v0 = ROTL32(v0, 20); \
105 v2 += v0; \
106 v1 ^= v2; \
107 v0 += v1; \
108 v0 = ROTL32(v0, 5); \
109 v2 += v0; \
110 v2 = ROTL32(v2, 22); \
111 v0 -= v1; \
112 v1 -= v2; \
113 v1 = ROTL32(v1, 17); \
114} STMT_END
115
116#define ZAPHOD32_MIX(v0,v1,v2,text) STMT_START { \
117 ZAPHOD32_WARN4("v0=%08x v1=%08x v2=%08x - ZAPHOD32 %s MIX\n", \
118 (unsigned int)v0,(unsigned int)v1,(unsigned int)v2, text ); \
119 v0 = ROTL32(v0,16) - v2; \
120 v1 = ROTR32(v1,13) ^ v2; \
121 v2 = ROTL32(v2,17) + v1; \
122 v0 = ROTR32(v0, 2) + v1; \
123 v1 = ROTR32(v1,17) - v0; \
124 v2 = ROTR32(v2, 7) ^ v0; \
125} STMT_END
126
127
128ZAPHOD32_STATIC_INLINE
129void zaphod32_seed_state (
130 const U8 *seed_ch,
131 U8 *state_ch
132) {
20e4c2ed 133 const U32 *seed= (const U32 *)seed_ch;
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134 U32 *state= (U32 *)state_ch;
135
136 /* hex expansion of pi, skipping first two digits. pi= 3.2[43f6...]*/
137 /* pi value in hex from here:
138 * http://turner.faculty.swau.edu/mathematics/materialslibrary/pi/pibases.html*/
139 /* Ensure that the three state vectors are nonzero regardless of the seed. */
140 /* The idea of these two steps is to ensure that the 0 state comes from a seed
141 * utterly unlike that of the value we replace it with.*/
142 state[0]= seed[0] ^ 0x43f6a888;
143 state[1]= seed[1] ^ 0x5a308d31;
144 state[2]= seed[2] ^ 0x3198a2e0;
145 if (!state[0]) state[0] = 1;
146 if (!state[1]) state[1] = 2;
147 if (!state[2]) state[2] = 4;
148 /* these are pseduo-randomly selected primes between 2**31 and 2**32
149 * (I generated a big list and then randomly chose some from the list) */
150 ZAPHOD32_SCRAMBLE32(state[0],0x9fade23b);
151 ZAPHOD32_SCRAMBLE32(state[1],0xaa6f908d);
152 ZAPHOD32_SCRAMBLE32(state[2],0xcdf6b72d);
3deca554 153
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154 /* now that we have scrambled we do some mixing to avalanche the
155 * state bits to gether */
156 ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE A 1/4");
157 ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE A 2/4");
158 ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE A 3/4");
159 ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE A 4/4");
160
161 /* and then scramble them again with different primes */
162 ZAPHOD32_SCRAMBLE32(state[0],0xc95d22a9);
163 ZAPHOD32_SCRAMBLE32(state[1],0x8497242b);
164 ZAPHOD32_SCRAMBLE32(state[2],0x9c5cc4e9);
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165
166 /* and a thorough final mix */
167 ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE B 1/5");
168 ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE B 2/5");
169 ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE B 3/5");
170 ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE B 4/5");
171 ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE B 5/5");
9d5e3f1a 172
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173}
174
175ZAPHOD32_STATIC_INLINE
176U32 zaphod32_hash_with_state(
177 const U8 *state_ch,
178 const U8 *key,
179 const STRLEN key_len
180) {
181 U32 *state= (U32 *)state_ch;
182 const U8 *end;
9995b99e 183 STRLEN len = key_len;
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184 U32 v0= state[0];
185 U32 v1= state[1];
e5a55128 186 U32 v2= state[2] ^ (0xC41A7AB1 * ((U32)key_len + 1));
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187
188 ZAPHOD32_WARN4("v0=%08x v1=%08x v2=%08x ln=%08x HASH START\n",
189 (unsigned int)state[0], (unsigned int)state[1],
190 (unsigned int)state[2], (unsigned int)key_len);
191 {
192 switch (len) {
193 default: goto zaphod32_read8;
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194 case 12: v2 += (U32)key[11] << 24; /* FALLTHROUGH */
195 case 11: v2 += (U32)key[10] << 16; /* FALLTHROUGH */
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196 case 10: v2 += (U32)U8TO16_LE(key+8);
197 v1 -= U8TO32_LE(key+4);
198 v0 += U8TO32_LE(key+0);
199 goto zaphod32_finalize;
f8a8fb6d 200 case 9: v2 += (U32)key[8]; /* FALLTHROUGH */
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201 case 8: v1 -= U8TO32_LE(key+4);
202 v0 += U8TO32_LE(key+0);
203 goto zaphod32_finalize;
f8a8fb6d 204 case 7: v2 += (U32)key[6]; /* FALLTHROUGH */
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205 case 6: v0 += (U32)U8TO16_LE(key+4);
206 v1 -= U8TO32_LE(key+0);
207 goto zaphod32_finalize;
f8a8fb6d 208 case 5: v0 += (U32)key[4]; /* FALLTHROUGH */
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209 case 4: v1 -= U8TO32_LE(key+0);
210 goto zaphod32_finalize;
f8a8fb6d 211 case 3: v2 += (U32)key[2]; /* FALLTHROUGH */
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212 case 2: v0 += (U32)U8TO16_LE(key);
213 break;
214 case 1: v0 += (U32)key[0];
215 break;
216 case 0: v2 ^= 0xFF;
217 break;
218
219 }
220 v0 -= v2;
221 v2 = ROTL32(v2, 8) ^ v0;
222 v0 = ROTR32(v0,16) + v2;
223 v2 += v0;
224 v0 += v0 >> 9;
225 v0 += v2;
226 v2 ^= v0;
227 v2 += v2 << 4;
228 v0 -= v2;
229 v2 = ROTR32(v2, 8) ^ v0;
230 v0 = ROTL32(v0,16) ^ v2;
231 v2 = ROTL32(v2,10) + v0;
232 v0 = ROTR32(v0,30) + v2;
233 v2 = ROTR32(v2,12);
234 return v0 ^ v2;
235 }
236
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237/* if (len >= 8) */ /* this block is only reached by a goto above, so this condition
238 is commented out, but if the above block is removed it would
239 be necessary to use this. */
240 {
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241zaphod32_read8:
242 len = key_len & 0x7;
243 end = key + key_len - len;
244 do {
245 v1 -= U8TO32_LE(key+0);
246 v0 += U8TO32_LE(key+4);
247 ZAPHOD32_MIX(v0,v1,v2,"MIX 2-WORDS A");
248 key += 8;
249 } while ( key < end );
250 }
251
252 if ( len >= 4 ) {
253 v1 -= U8TO32_LE(key);
254 key += 4;
255 }
256
257 v0 += (U32)(key_len) << 24;
258 switch (len & 0x3) {
f8a8fb6d 259 case 3: v2 += (U32)key[2]; /* FALLTHROUGH */
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260 case 2: v0 += (U32)U8TO16_LE(key);
261 break;
262 case 1: v0 += (U32)key[0];
263 break;
264 case 0: v2 ^= 0xFF;
f8a8fb6d 265 break;
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266 }
267zaphod32_finalize:
268 ZAPHOD32_FINALIZE(v0,v1,v2);
269
270 ZAPHOD32_WARN4("v0=%08x v1=%08x v2=%08x hh=%08x - FINAL\n\n",
271 (unsigned int)v0, (unsigned int)v1, (unsigned int)v2,
272 (unsigned int)v0 ^ v1 ^ v2);
273
274 return v0 ^ v1 ^ v2;
275}
276
277ZAPHOD32_STATIC_INLINE U32 zaphod32_hash(
278 const U8 *seed_ch,
279 const U8 *key,
280 const STRLEN key_len
281) {
3deca554 282 U32 state[3];
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283 zaphod32_seed_state(seed_ch,(U8*)state);
284 return zaphod32_hash_with_state((U8*)state,key,key_len);
285}
286
287#endif