[ovs.git] / lib / hash.c

/*
 * Copyright (c) 2008, 2009, 2010, 2012, 2013, 2014 Nicira, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include <config.h>
#include "hash.h"
#include <string.h>
#include "unaligned.h"

/* Returns the hash of 'a', 'b', and 'c'. */
uint32_t
hash_3words(uint32_t a, uint32_t b, uint32_t c)
{
    return hash_finish(hash_add(hash_add(hash_add(a, 0), b), c), 12);
}

/* Returns the hash of the 'n' bytes at 'p', starting from 'basis'. */
uint32_t
hash_bytes(const void *p_, size_t n, uint32_t basis)
{
    const uint32_t *p = p_;
    size_t orig_n = n;
    uint32_t hash;

    hash = basis;
    while (n >= 4) {
        hash = hash_add(hash, get_unaligned_u32(p));
        n -= 4;
        p += 1;
    }

    if (n) {
        uint32_t tmp = 0;

        memcpy(&tmp, p, n);
        hash = hash_add(hash, tmp);
    }

    return hash_finish(hash, orig_n);
}

uint32_t
hash_double(double x, uint32_t basis)
{
    uint32_t value[2];
    BUILD_ASSERT_DECL(sizeof x == sizeof value);

    memcpy(value, &x, sizeof value);
    return hash_3words(value[0], value[1], basis);
}

uint32_t
hash_words__(const uint32_t p[], size_t n_words, uint32_t basis)
{
    return hash_words_inline(p, n_words, basis);
}

uint32_t
hash_words64__(const uint64_t p[], size_t n_words, uint32_t basis)
{
    return hash_words64_inline(p, n_words, basis);
}

#if !(defined(__x86_64__))
void
hash_bytes128(const void *p_, size_t len, uint32_t basis, ovs_u128 *out)
{
    const uint32_t c1 = 0x239b961b;
    const uint32_t c2 = 0xab0e9789;
    const uint32_t c3 = 0x38b34ae5;
    const uint32_t c4 = 0xa1e38b93;
    const uint8_t *tail, *data = (const uint8_t *)p_;
    const uint32_t *blocks = (const uint32_t *)p_;
    const int nblocks = len / 16;
    uint32_t h1 = basis;
    uint32_t h2 = basis;
    uint32_t h3 = basis;
    uint32_t h4 = basis;
    uint32_t k1, k2, k3, k4;

    /* Body */
    for (int i = 0; i < nblocks; i++) {
        uint32_t k1 = get_unaligned_u32(&blocks[i * 4 + 0]);
        uint32_t k2 = get_unaligned_u32(&blocks[i * 4 + 1]);
        uint32_t k3 = get_unaligned_u32(&blocks[i * 4 + 2]);
        uint32_t k4 = get_unaligned_u32(&blocks[i * 4 + 3]);

        k1 *= c1;
        k1 = hash_rot(k1, 15);
        k1 *= c2;
        h1 ^= k1;

        h1 = hash_rot(h1, 19);
        h1 += h2;
        h1 = h1 * 5 + 0x561ccd1b;

        k2 *= c2;
        k2 = hash_rot(k2, 16);
        k2 *= c3;
        h2 ^= k2;

        h2 = hash_rot(h2, 17);
        h2 += h3;
        h2 = h2 * 5 + 0x0bcaa747;

        k3 *= c3;
        k3 = hash_rot(k3, 17);
        k3 *= c4;
        h3 ^= k3;

        h3 = hash_rot(h3, 15);
        h3 += h4;
        h3 = h3 * 5 + 0x96cd1c35;

        k4 *= c4;
        k4 = hash_rot(k4, 18);
        k4 *= c1;
        h4 ^= k4;

        h4 = hash_rot(h4, 13);
        h4 += h1;
        h4 = h4 * 5 + 0x32ac3b17;
    }

    /* Tail */
    k1 = k2 = k3 = k4 = 0;
    tail = data + nblocks * 16;
    switch (len & 15) {
    case 15:
        k4 ^= tail[14] << 16;
    case 14:
        k4 ^= tail[13] << 8;
    case 13:
        k4 ^= tail[12] << 0;
        k4 *= c4;
        k4 = hash_rot(k4, 18);
        k4 *= c1;
        h4 ^= k4;

    case 12:
        k3 ^= tail[11] << 24;
    case 11:
        k3 ^= tail[10] << 16;
    case 10:
        k3 ^= tail[9] << 8;
    case 9:
        k3 ^= tail[8] << 0;
        k3 *= c3;
        k3 = hash_rot(k3, 17);
        k3 *= c4;
        h3 ^= k3;

    case 8:
        k2 ^= tail[7] << 24;
    case 7:
        k2 ^= tail[6] << 16;
    case 6:
        k2 ^= tail[5] << 8;
    case 5:
        k2 ^= tail[4] << 0;
        k2 *= c2;
        k2 = hash_rot(k2, 16);
        k2 *= c3;
        h2 ^= k2;

    case 4:
        k1 ^= tail[3] << 24;
    case 3:
        k1 ^= tail[2] << 16;
    case 2:
        k1 ^= tail[1] << 8;
    case 1:
        k1 ^= tail[0] << 0;
        k1 *= c1;
        k1 = hash_rot(k1, 15);
        k1 *= c2;
        h1 ^= k1;
    };

    /* Finalization */
    h1 ^= len;
    h2 ^= len;
    h3 ^= len;
    h4 ^= len;

    h1 += h2;
    h1 += h3;
    h1 += h4;
    h2 += h1;
    h3 += h1;
    h4 += h1;

    h1 = mhash_finish(h1);
    h2 = mhash_finish(h2);
    h3 = mhash_finish(h3);
    h4 = mhash_finish(h4);

    h1 += h2;
    h1 += h3;
    h1 += h4;
    h2 += h1;
    h3 += h1;
    h4 += h1;

    out->u32[0] = h1;
    out->u32[1] = h2;
    out->u32[2] = h3;
    out->u32[3] = h4;
}

#else /* __x86_64__ */

static inline uint64_t
hash_rot64(uint64_t x, int8_t r)
{
    return (x << r) | (x >> (64 - r));
}

static inline uint64_t
fmix64(uint64_t k)
{
    k ^= k >> 33;
    k *= 0xff51afd7ed558ccdULL;
    k ^= k >> 33;
    k *= 0xc4ceb9fe1a85ec53ULL;
    k ^= k >> 33;

    return k;
}

void
hash_bytes128(const void *p_, size_t len, uint32_t basis, ovs_u128 *out)
{
    const uint64_t c1 = 0x87c37b91114253d5ULL;
    const uint64_t c2 = 0x4cf5ad432745937fULL;
    const uint8_t *tail, *data = (const uint8_t *)p_;
    const uint64_t *blocks = (const uint64_t *)p_;
    const int nblocks = len / 16;
    uint64_t h1 = basis;
    uint64_t h2 = basis;
    uint64_t k1, k2;

    /* Body */
    for (int i = 0; i < nblocks; i++) {
        k1 = get_unaligned_u64(&blocks[i * 2 + 0]);
        k2 = get_unaligned_u64(&blocks[i * 2 + 1]);

        k1 *= c1;
        k1 = hash_rot64(k1, 31);
        k1 *= c2;
        h1 ^= k1;

        h1 = hash_rot64(h1, 27);
        h1 += h2;
        h1 = h1 * 5 + 0x52dce729;

        k2 *= c2;
        k2 = hash_rot64(k2, 33);
        k2 *= c1;
        h2 ^= k2;

        h2 = hash_rot64(h2, 31);
        h2 += h1;
        h2 = h2 * 5 + 0x38495ab5;
    }

    /* Tail */
    k1 = 0;
    k2 = 0;
    tail = data + nblocks * 16;
    switch (len & 15) {
    case 15:
        k2 ^= ((uint64_t) tail[14]) << 48;
    case 14:
        k2 ^= ((uint64_t) tail[13]) << 40;
    case 13:
        k2 ^= ((uint64_t) tail[12]) << 32;
    case 12:
        k2 ^= ((uint64_t) tail[11]) << 24;
    case 11:
        k2 ^= ((uint64_t) tail[10]) << 16;
    case 10:
        k2 ^= ((uint64_t) tail[9]) << 8;
    case 9:
        k2 ^= ((uint64_t) tail[8]) << 0;
        k2 *= c2;
        k2 = hash_rot64(k2, 33);
        k2 *= c1;
        h2 ^= k2;

    case 8:
        k1 ^= ((uint64_t) tail[7]) << 56;
    case 7:
        k1 ^= ((uint64_t) tail[6]) << 48;
    case 6:
        k1 ^= ((uint64_t) tail[5]) << 40;
    case 5:
        k1 ^= ((uint64_t) tail[4]) << 32;
    case 4:
        k1 ^= ((uint64_t) tail[3]) << 24;
    case 3:
        k1 ^= ((uint64_t) tail[2]) << 16;
    case 2:
        k1 ^= ((uint64_t) tail[1]) << 8;
    case 1:
        k1 ^= ((uint64_t) tail[0]) << 0;
        k1 *= c1;
        k1 = hash_rot64(k1, 31);
        k1 *= c2;
        h1 ^= k1;
    };

    /* Finalization */
    h1 ^= len;
    h2 ^= len;
    h1 += h2;
    h2 += h1;
    h1 = fmix64(h1);
    h2 = fmix64(h2);
    h1 += h2;
    h2 += h1;

    out->u64.lo = h1;
    out->u64.hi = h2;
}
#endif /* __x86_64__ */
Commit	Line	Data
064af421	1	/*
468cdd91	2	* Copyright (c) 2008, 2009, 2010, 2012, 2013, 2014 Nicira, Inc.
064af421	3	*
a14bc59f BP	4	* Licensed under the Apache License, Version 2.0 (the "License");
	5	* you may not use this file except in compliance with the License.
	6	* You may obtain a copy of the License at:
064af421	7	*
a14bc59f BP	8	* http://www.apache.org/licenses/LICENSE-2.0
	9	*
	10	* Unless required by applicable law or agreed to in writing, software
	11	* distributed under the License is distributed on an "AS IS" BASIS,
	12	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	13	* See the License for the specific language governing permissions and
	14	* limitations under the License.
064af421 BP	15	*/
	16	#include <config.h>
	17	#include "hash.h"
	18	#include <string.h>
7376da64	19	#include "unaligned.h"
064af421	20
1f26e796	21	/* Returns the hash of 'a', 'b', and 'c'. */
cce1d8bd	22	uint32_t
1f26e796	23	hash_3words(uint32_t a, uint32_t b, uint32_t c)
cce1d8bd	24	{
33c6a1b9	25	return hash_finish(hash_add(hash_add(hash_add(a, 0), b), c), 12);
1f26e796 BP	26	}
1f26e796 BP	27
064af421 BP	28	/* Returns the hash of the 'n' bytes at 'p', starting from 'basis'. */
	29	uint32_t
	30	hash_bytes(const void *p_, size_t n, uint32_t basis)
	31	{
db5a1019	32	const uint32_t *p = p_;
c49d1dd1 BP	33	size_t orig_n = n;
c49d1dd1 BP	34	uint32_t hash;
064af421	35
c49d1dd1 BP	36	hash = basis;
c49d1dd1 BP	37	while (n >= 4) {
33c6a1b9	38	hash = hash_add(hash, get_unaligned_u32(p));
c49d1dd1	39	n -= 4;
db5a1019	40	p += 1;
064af421 BP	41	}
	42
	43	if (n) {
c49d1dd1	44	uint32_t tmp = 0;
7376da64	45
c49d1dd1	46	memcpy(&tmp, p, n);
33c6a1b9	47	hash = hash_add(hash, tmp);
064af421 BP	48	}
064af421 BP	49
33c6a1b9	50	return hash_finish(hash, orig_n);
064af421	51	}
9879b94f	52
c49d1dd1 BP	53	uint32_t
	54	hash_double(double x, uint32_t basis)
	55	{
	56	uint32_t value[2];
	57	BUILD_ASSERT_DECL(sizeof x == sizeof value);
	58
	59	memcpy(value, &x, sizeof value);
	60	return hash_3words(value[0], value[1], basis);
	61	}
ff8eeabd JR	62
	63	uint32_t
	64	hash_words__(const uint32_t p[], size_t n_words, uint32_t basis)
	65	{
	66	return hash_words_inline(p, n_words, basis);
	67	}
	68
	69	uint32_t
4ad07ad7	70	hash_words64__(const uint64_t p[], size_t n_words, uint32_t basis)
ff8eeabd JR	71	{
	72	return hash_words64_inline(p, n_words, basis);
	73	}
468cdd91 JS	74
	75	#if !(defined(__x86_64__))
	76	void
	77	hash_bytes128(const void p_, size_t len, uint32_t basis, ovs_u128 out)
	78	{
	79	const uint32_t c1 = 0x239b961b;
	80	const uint32_t c2 = 0xab0e9789;
	81	const uint32_t c3 = 0x38b34ae5;
	82	const uint32_t c4 = 0xa1e38b93;
	83	const uint8_t tail, data = (const uint8_t *)p_;
	84	const uint32_t blocks = (const uint32_t )p_;
	85	const int nblocks = len / 16;
	86	uint32_t h1 = basis;
	87	uint32_t h2 = basis;
	88	uint32_t h3 = basis;
	89	uint32_t h4 = basis;
	90	uint32_t k1, k2, k3, k4;
	91
	92	/* Body */
	93	for (int i = 0; i < nblocks; i++) {
	94	uint32_t k1 = get_unaligned_u32(&blocks[i * 4 + 0]);
	95	uint32_t k2 = get_unaligned_u32(&blocks[i * 4 + 1]);
	96	uint32_t k3 = get_unaligned_u32(&blocks[i * 4 + 2]);
	97	uint32_t k4 = get_unaligned_u32(&blocks[i * 4 + 3]);
	98
	99	k1 *= c1;
	100	k1 = hash_rot(k1, 15);
	101	k1 *= c2;
	102	h1 ^= k1;
	103
	104	h1 = hash_rot(h1, 19);
	105	h1 += h2;
	106	h1 = h1 * 5 + 0x561ccd1b;
	107
	108	k2 *= c2;
	109	k2 = hash_rot(k2, 16);
	110	k2 *= c3;
	111	h2 ^= k2;
	112
	113	h2 = hash_rot(h2, 17);
	114	h2 += h3;
	115	h2 = h2 * 5 + 0x0bcaa747;
	116
	117	k3 *= c3;
	118	k3 = hash_rot(k3, 17);
	119	k3 *= c4;
	120	h3 ^= k3;
	121
	122	h3 = hash_rot(h3, 15);
	123	h3 += h4;
	124	h3 = h3 * 5 + 0x96cd1c35;
	125
	126	k4 *= c4;
	127	k4 = hash_rot(k4, 18);
	128	k4 *= c1;
	129	h4 ^= k4;
	130
	131	h4 = hash_rot(h4, 13);
	132	h4 += h1;
	133	h4 = h4 * 5 + 0x32ac3b17;
	134	}
	135
	136	/* Tail */
	137	k1 = k2 = k3 = k4 = 0;
138	tail = data + nblocks * 16;
139	switch (len & 15) {
140	case 15:
141	k4 ^= tail[14] << 16;
142	case 14:
143	k4 ^= tail[13] << 8;
144	case 13:
145	k4 ^= tail[12] << 0;
146	k4 *= c4;
147	k4 = hash_rot(k4, 18);
148	k4 *= c1;
149	h4 ^= k4;
150
151	case 12:
152	k3 ^= tail[11] << 24;
153	case 11:
154	k3 ^= tail[10] << 16;
155	case 10:
156	k3 ^= tail[9] << 8;
157	case 9:
158	k3 ^= tail[8] << 0;
159	k3 *= c3;
160	k3 = hash_rot(k3, 17);
161	k3 *= c4;
162	h3 ^= k3;
163
164	case 8:
165	k2 ^= tail[7] << 24;
166	case 7:
167	k2 ^= tail[6] << 16;
168	case 6:
169	k2 ^= tail[5] << 8;
170	case 5:
171	k2 ^= tail[4] << 0;
172	k2 *= c2;
173	k2 = hash_rot(k2, 16);
174	k2 *= c3;
175	h2 ^= k2;
176
177	case 4:
178	k1 ^= tail[3] << 24;
179	case 3:
180	k1 ^= tail[2] << 16;
181	case 2:
182	k1 ^= tail[1] << 8;
183	case 1:
184	k1 ^= tail[0] << 0;
185	k1 *= c1;
186	k1 = hash_rot(k1, 15);
187	k1 *= c2;
188	h1 ^= k1;
189	};
190
191	/* Finalization */
192	h1 ^= len;
193	h2 ^= len;
194	h3 ^= len;
195	h4 ^= len;
196
197	h1 += h2;
198	h1 += h3;
199	h1 += h4;
200	h2 += h1;
201	h3 += h1;
202	h4 += h1;
203
204	h1 = mhash_finish(h1);
205	h2 = mhash_finish(h2);
206	h3 = mhash_finish(h3);
207	h4 = mhash_finish(h4);
208
209	h1 += h2;
210	h1 += h3;
211	h1 += h4;
212	h2 += h1;
213	h3 += h1;
214	h4 += h1;
215
216	out->u32[0] = h1;
217	out->u32[1] = h2;
218	out->u32[2] = h3;
219	out->u32[3] = h4;
220	}
221
222	#else /* __x86_64__ */
223
224	static inline uint64_t
225	hash_rot64(uint64_t x, int8_t r)
226	{
227	return (x << r) \| (x >> (64 - r));
228	}
229
230	static inline uint64_t
231	fmix64(uint64_t k)
232	{
233	k ^= k >> 33;
234	k *= 0xff51afd7ed558ccdULL;
235	k ^= k >> 33;
236	k *= 0xc4ceb9fe1a85ec53ULL;
237	k ^= k >> 33;
238
239	return k;
240	}
241
242	void
243	hash_bytes128(const void p_, size_t len, uint32_t basis, ovs_u128 out)
244	{
245	const uint64_t c1 = 0x87c37b91114253d5ULL;
246	const uint64_t c2 = 0x4cf5ad432745937fULL;
247	const uint8_t tail, data = (const uint8_t *)p_;
248	const uint64_t blocks = (const uint64_t )p_;
249	const int nblocks = len / 16;
250	uint64_t h1 = basis;
251	uint64_t h2 = basis;
252	uint64_t k1, k2;
253
254	/* Body */
255	for (int i = 0; i < nblocks; i++) {
256	k1 = get_unaligned_u64(&blocks[i * 2 + 0]);
257	k2 = get_unaligned_u64(&blocks[i * 2 + 1]);
258
259	k1 *= c1;
260	k1 = hash_rot64(k1, 31);
261	k1 *= c2;
262	h1 ^= k1;
263
264	h1 = hash_rot64(h1, 27);
265	h1 += h2;
266	h1 = h1 * 5 + 0x52dce729;
267
268	k2 *= c2;
269	k2 = hash_rot64(k2, 33);
270	k2 *= c1;
271	h2 ^= k2;
272
273	h2 = hash_rot64(h2, 31);
274	h2 += h1;
275	h2 = h2 * 5 + 0x38495ab5;
276	}
277
278	/* Tail */
279	k1 = 0;
280	k2 = 0;
281	tail = data + nblocks * 16;
282	switch (len & 15) {
283	case 15:
284	k2 ^= ((uint64_t) tail[14]) << 48;
285	case 14:
286	k2 ^= ((uint64_t) tail[13]) << 40;
287	case 13:
288	k2 ^= ((uint64_t) tail[12]) << 32;
289	case 12:
290	k2 ^= ((uint64_t) tail[11]) << 24;
291	case 11:
292	k2 ^= ((uint64_t) tail[10]) << 16;
293	case 10:
294	k2 ^= ((uint64_t) tail[9]) << 8;
295	case 9:
296	k2 ^= ((uint64_t) tail[8]) << 0;
297	k2 *= c2;
298	k2 = hash_rot64(k2, 33);
299	k2 *= c1;
300	h2 ^= k2;
301
302	case 8:
303	k1 ^= ((uint64_t) tail[7]) << 56;
304	case 7:
305	k1 ^= ((uint64_t) tail[6]) << 48;
306	case 6:
307	k1 ^= ((uint64_t) tail[5]) << 40;
308	case 5:
309	k1 ^= ((uint64_t) tail[4]) << 32;
310	case 4:
311	k1 ^= ((uint64_t) tail[3]) << 24;
312	case 3:
313	k1 ^= ((uint64_t) tail[2]) << 16;
314	case 2:
315	k1 ^= ((uint64_t) tail[1]) << 8;
316	case 1:
317	k1 ^= ((uint64_t) tail[0]) << 0;
318	k1 *= c1;
319	k1 = hash_rot64(k1, 31);
320	k1 *= c2;
321	h1 ^= k1;
322	};
323
324	/* Finalization */
325	h1 ^= len;
326	h2 ^= len;
327	h1 += h2;
328	h2 += h1;
329	h1 = fmix64(h1);
330	h2 = fmix64(h2);
331	h1 += h2;
332	h2 += h1;
333
334	out->u64.lo = h1;
335	out->u64.hi = h2;
336	}
337	#endif /* __x86_64__ */