[dpdk-dev] [PATCH 2/2] hash: rte_hash_crc uses 8- and 4-byte CRC32 intrinsics
Yerden Zhumabekov
e_zhumabekov at sts.kz
Wed Sep 3 08:05:51 CEST 2014
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 either 8 and 4-byte CRC32 intrinsics.
Signed-off-by: Yerden Zhumabekov <e_zhumabekov at sts.kz>
---
lib/librte_hash/rte_hash_crc.h | 31 +++++++++++++++++++++++--------
1 file changed, 23 insertions(+), 8 deletions(-)
diff --git a/lib/librte_hash/rte_hash_crc.h b/lib/librte_hash/rte_hash_crc.h
index 102b2a0..d023e5d 100644
--- a/lib/librte_hash/rte_hash_crc.h
+++ b/lib/librte_hash/rte_hash_crc.h
@@ -95,23 +95,38 @@ 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;
}
--
1.7.9.5
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