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Diffstat (limited to 'include/qemu/xxhash.h')
| -rw-r--r-- | include/qemu/xxhash.h | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/include/qemu/xxhash.h b/include/qemu/xxhash.h new file mode 100644 index 0000000000..fe35dde328 --- /dev/null +++ b/include/qemu/xxhash.h @@ -0,0 +1,122 @@ +/* + * xxHash - Fast Hash algorithm + * Copyright (C) 2012-2016, Yann Collet + * + * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * + Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * You can contact the author at : + * - xxHash source repository : https://github.com/Cyan4973/xxHash + */ + +#ifndef QEMU_XXHASH_H +#define QEMU_XXHASH_H + +#include "qemu/bitops.h" + +#define PRIME32_1 2654435761U +#define PRIME32_2 2246822519U +#define PRIME32_3 3266489917U +#define PRIME32_4 668265263U +#define PRIME32_5 374761393U + +#define QEMU_XXHASH_SEED 1 + +/* + * xxhash32, customized for input variables that are not guaranteed to be + * contiguous in memory. + */ +static inline uint32_t +qemu_xxhash7(uint64_t ab, uint64_t cd, uint32_t e, uint32_t f, uint32_t g) +{ + uint32_t v1 = QEMU_XXHASH_SEED + PRIME32_1 + PRIME32_2; + uint32_t v2 = QEMU_XXHASH_SEED + PRIME32_2; + uint32_t v3 = QEMU_XXHASH_SEED + 0; + uint32_t v4 = QEMU_XXHASH_SEED - PRIME32_1; + uint32_t a = ab >> 32; + uint32_t b = ab; + uint32_t c = cd >> 32; + uint32_t d = cd; + uint32_t h32; + + v1 += a * PRIME32_2; + v1 = rol32(v1, 13); + v1 *= PRIME32_1; + + v2 += b * PRIME32_2; + v2 = rol32(v2, 13); + v2 *= PRIME32_1; + + v3 += c * PRIME32_2; + v3 = rol32(v3, 13); + v3 *= PRIME32_1; + + v4 += d * PRIME32_2; + v4 = rol32(v4, 13); + v4 *= PRIME32_1; + + h32 = rol32(v1, 1) + rol32(v2, 7) + rol32(v3, 12) + rol32(v4, 18); + h32 += 28; + + h32 += e * PRIME32_3; + h32 = rol32(h32, 17) * PRIME32_4; + + h32 += f * PRIME32_3; + h32 = rol32(h32, 17) * PRIME32_4; + + h32 += g * PRIME32_3; + h32 = rol32(h32, 17) * PRIME32_4; + + h32 ^= h32 >> 15; + h32 *= PRIME32_2; + h32 ^= h32 >> 13; + h32 *= PRIME32_3; + h32 ^= h32 >> 16; + + return h32; +} + +static inline uint32_t qemu_xxhash2(uint64_t ab) +{ + return qemu_xxhash7(ab, 0, 0, 0, 0); +} + +static inline uint32_t qemu_xxhash4(uint64_t ab, uint64_t cd) +{ + return qemu_xxhash7(ab, cd, 0, 0, 0); +} + +static inline uint32_t qemu_xxhash5(uint64_t ab, uint64_t cd, uint32_t e) +{ + return qemu_xxhash7(ab, cd, e, 0, 0); +} + +static inline uint32_t qemu_xxhash6(uint64_t ab, uint64_t cd, uint32_t e, + uint32_t f) +{ + return qemu_xxhash7(ab, cd, e, f, 0); +} + +#endif /* QEMU_XXHASH_H */ |