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hash: slice CRC data into 8-byte pieces

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Calculating hash for data of variable length is more efficient
when that data is sliced into 8-byte pieces. The rest part of data
is hashed using CRC32 functions with either 8 and 4 byte operands.

Signed-off-by: Yerden Zhumabekov <e_zhumabekov@sts.kz>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
This commit is contained in:
Yerden Zhumabekov 2015-01-29 14:50:26 +06:00 committed by Thomas Monjalon
parent 8bae1da2af
commit 614289298d
1 changed files with 24 additions and 9 deletions
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33
lib/librte_hash/rte_hash_crc.h
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@ -486,7 +486,7 @@ rte_hash_crc_8byte(uint64_t data, uint32_t init_val)
}
/**
* Use crc32 instruction to perform a hash.
* Calculate CRC32 hash on user-supplied byte array.
*
* @param data
* Data to perform hash on.
@ -501,23 +501,38 @@ 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;
uint64_t temp = 0;
const uint64_t *p64 = (const uint64_t *)data;
for (i = 0; i < data_len / 4; i++) {
init_val = rte_hash_crc_4byte(*p32++, init_val);
for (i = 0; i < data_len / 8; i++) {
init_val = rte_hash_crc_8byte(*p64++, init_val);
}
switch (3 - (data_len & 0x03)) {
switch (7 - (data_len & 0x07)) {
case 0:
temp |= *((const uint8_t *)p32 + 2) << 16;
temp |= (uint64_t) *((const uint8_t *)p64 + 6) << 48;
/* Fallthrough */
case 1:
temp |= *((const uint8_t *)p32 + 1) << 8;
temp |= (uint64_t) *((const uint8_t *)p64 + 5) << 40;
/* Fallthrough */
case 2:
temp |= *((const uint8_t *)p32);
temp |= (uint64_t) *((const uint8_t *)p64 + 4) << 32;
temp |= *((const uint32_t *)p64);
init_val = rte_hash_crc_8byte(temp, init_val);
break;
case 3:
init_val = rte_hash_crc_4byte(*(const uint32_t *)p64, init_val);
break;
case 4:
temp |= *((const uint8_t *)p64 + 2) << 16;
/* Fallthrough */
case 5:
temp |= *((const uint8_t *)p64 + 1) << 8;
/* Fallthrough */
case 6:
temp |= *((const uint8_t *)p64);
init_val = rte_hash_crc_4byte(temp, init_val);
/* Fallthrough */
default:
break;
}