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/*-
* BSD LICENSE
*
* Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
* All rights reserved.
*
* 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.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 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.
*/
#ifndef _RTE_HASH_CRC_H_
#define _RTE_HASH_CRC_H_
/**
* @file
*
* RTE CRC Hash
*/
#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
#include <nmmintrin.h>
/**
* Use single crc32 instruction to perform a hash on a 4 byte value.
*
* @param data
* Data to perform hash on.
* @param init_val
* Value to initialise hash generator.
* @return
* 32bit calculated hash value.
*/
static inline uint32_t
rte_hash_crc_4byte(uint32_t data, uint32_t init_val)
{
return _mm_crc32_u32(init_val, data);
}
/**
* Use crc32 instruction to perform a hash.
*
* @param data
* Data to perform hash on.
* @param data_len
* How many bytes to use to calculate hash value.
* @param init_val
* Value to initialise hash generator.
* @return
* 32bit calculated hash value.
*/
static inline uint32_t
rte_hash_crc(const void *data, uint32_t data_len, uint32_t init_val)
{
unsigned i;
uint32_t temp = 0;
const uint32_t *p32 = (const uint32_t *)data;
for (i = 0; i < data_len / 4; i++) {
init_val = rte_hash_crc_4byte(*p32++, init_val);
}
switch (3 - (data_len & 0x03)) {
case 0:
temp |= *((const uint8_t *)p32 + 2) << 16;
/* Fallthrough */
case 1:
temp |= *((const uint8_t *)p32 + 1) << 8;
/* Fallthrough */
case 2:
temp |= *((const uint8_t *)p32);
init_val = rte_hash_crc_4byte(temp, init_val);
default:
break;
}
return init_val;
}
#ifdef __cplusplus
}
#endif
#endif /* _RTE_HASH_CRC_H_ */
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