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/*
* Copyright © 2009,2012 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* Authors:
* Eric Anholt <eric@anholt.net>
*
*/
#ifndef _FNV1A_H
#define _FNV1A_H
enum {
_mesa_fnv32_1a_offset_bias = 2166136261u,
};
/**
* Quick FNV-1a hash implementation based on:
* http://www.isthe.com/chongo/tech/comp/fnv/
*
* FNV-1a is not be the best hash out there -- Jenkins's lookup3 is supposed
* to be quite good, and it probably beats FNV. But FNV has the advantage
* that it involves almost no code. For an improvement on both, see Paul
* Hsieh's http://www.azillionmonkeys.com/qed/hash.html
*/
static inline uint32_t
_mesa_fnv32_1a_accumulate_block(uint32_t hash, const void *data, size_t size)
{
const uint8_t *bytes = (const uint8_t *)data;
while (size-- != 0) {
hash ^= *bytes;
hash = hash * 0x01000193;
bytes++;
}
return hash;
}
#define _mesa_fnv32_1a_accumulate(hash, expr) \
_mesa_fnv32_1a_accumulate_block(hash, &(expr), sizeof(expr))
#endif
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