numam-dpdk/lib/librte_fib/trie_avx512.c
Vladimir Medvedkin 1e5630e40d fib6: add AVX512 lookup
Add new lookup implementation for FIB6 trie algorithm using
AVX512 instruction set

Signed-off-by: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
2020-10-28 21:29:13 +01:00

270 lines
8.1 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2020 Intel Corporation
*/
#include <rte_vect.h>
#include <rte_fib6.h>
#include "trie.h"
#include "trie_avx512.h"
static __rte_always_inline void
transpose_x16(uint8_t ips[16][RTE_FIB6_IPV6_ADDR_SIZE],
__m512i *first, __m512i *second, __m512i *third, __m512i *fourth)
{
__m512i tmp1, tmp2, tmp3, tmp4;
__m512i tmp5, tmp6, tmp7, tmp8;
const __rte_x86_zmm_t perm_idxes = {
.u32 = { 0, 4, 8, 12, 2, 6, 10, 14,
1, 5, 9, 13, 3, 7, 11, 15
},
};
/* load all ip addresses */
tmp1 = _mm512_loadu_si512(&ips[0][0]);
tmp2 = _mm512_loadu_si512(&ips[4][0]);
tmp3 = _mm512_loadu_si512(&ips[8][0]);
tmp4 = _mm512_loadu_si512(&ips[12][0]);
/* transpose 4 byte chunks of 16 ips */
tmp5 = _mm512_unpacklo_epi32(tmp1, tmp2);
tmp7 = _mm512_unpackhi_epi32(tmp1, tmp2);
tmp6 = _mm512_unpacklo_epi32(tmp3, tmp4);
tmp8 = _mm512_unpackhi_epi32(tmp3, tmp4);
tmp1 = _mm512_unpacklo_epi32(tmp5, tmp6);
tmp3 = _mm512_unpackhi_epi32(tmp5, tmp6);
tmp2 = _mm512_unpacklo_epi32(tmp7, tmp8);
tmp4 = _mm512_unpackhi_epi32(tmp7, tmp8);
/* first 4-byte chunks of ips[] */
*first = _mm512_permutexvar_epi32(perm_idxes.z, tmp1);
/* second 4-byte chunks of ips[] */
*second = _mm512_permutexvar_epi32(perm_idxes.z, tmp3);
/* third 4-byte chunks of ips[] */
*third = _mm512_permutexvar_epi32(perm_idxes.z, tmp2);
/* fourth 4-byte chunks of ips[] */
*fourth = _mm512_permutexvar_epi32(perm_idxes.z, tmp4);
}
static __rte_always_inline void
transpose_x8(uint8_t ips[8][RTE_FIB6_IPV6_ADDR_SIZE],
__m512i *first, __m512i *second)
{
__m512i tmp1, tmp2, tmp3, tmp4;
const __rte_x86_zmm_t perm_idxes = {
.u64 = { 0, 2, 4, 6, 1, 3, 5, 7
},
};
tmp1 = _mm512_loadu_si512(&ips[0][0]);
tmp2 = _mm512_loadu_si512(&ips[4][0]);
tmp3 = _mm512_unpacklo_epi64(tmp1, tmp2);
*first = _mm512_permutexvar_epi64(perm_idxes.z, tmp3);
tmp4 = _mm512_unpackhi_epi64(tmp1, tmp2);
*second = _mm512_permutexvar_epi64(perm_idxes.z, tmp4);
}
static __rte_always_inline void
trie_vec_lookup_x16(void *p, uint8_t ips[16][RTE_FIB6_IPV6_ADDR_SIZE],
uint64_t *next_hops, int size)
{
struct rte_trie_tbl *dp = (struct rte_trie_tbl *)p;
const __m512i zero = _mm512_set1_epi32(0);
const __m512i lsb = _mm512_set1_epi32(1);
const __m512i two_lsb = _mm512_set1_epi32(3);
__m512i first, second, third, fourth; /*< IPv6 four byte chunks */
__m512i idxes, res, shuf_idxes;
__m512i tmp, tmp2, bytes, byte_chunk, base_idxes;
/* used to mask gather values if size is 2 (16 bit next hops) */
const __m512i res_msk = _mm512_set1_epi32(UINT16_MAX);
const __rte_x86_zmm_t bswap = {
.u8 = { 2, 1, 0, 255, 6, 5, 4, 255,
10, 9, 8, 255, 14, 13, 12, 255,
2, 1, 0, 255, 6, 5, 4, 255,
10, 9, 8, 255, 14, 13, 12, 255,
2, 1, 0, 255, 6, 5, 4, 255,
10, 9, 8, 255, 14, 13, 12, 255,
2, 1, 0, 255, 6, 5, 4, 255,
10, 9, 8, 255, 14, 13, 12, 255
},
};
const __mmask64 k = 0x1111111111111111;
int i = 3;
__mmask16 msk_ext, new_msk;
__mmask16 exp_msk = 0x5555;
transpose_x16(ips, &first, &second, &third, &fourth);
/* get_tbl24_idx() for every 4 byte chunk */
idxes = _mm512_shuffle_epi8(first, bswap.z);
/**
* lookup in tbl24
* Put it inside branch to make compiller happy with -O0
*/
if (size == sizeof(uint16_t)) {
res = _mm512_i32gather_epi32(idxes, (const int *)dp->tbl24, 2);
res = _mm512_and_epi32(res, res_msk);
} else
res = _mm512_i32gather_epi32(idxes, (const int *)dp->tbl24, 4);
/* get extended entries indexes */
msk_ext = _mm512_test_epi32_mask(res, lsb);
tmp = _mm512_srli_epi32(res, 1);
/* idxes to retrieve bytes */
shuf_idxes = _mm512_setr_epi32(3, 7, 11, 15,
19, 23, 27, 31,
35, 39, 43, 47,
51, 55, 59, 63);
base_idxes = _mm512_setr_epi32(0, 4, 8, 12,
16, 20, 24, 28,
32, 36, 40, 44,
48, 52, 56, 60);
/* traverse down the trie */
while (msk_ext) {
idxes = _mm512_maskz_slli_epi32(msk_ext, tmp, 8);
byte_chunk = (i < 8) ?
((i >= 4) ? second : first) :
((i >= 12) ? fourth : third);
bytes = _mm512_maskz_shuffle_epi8(k, byte_chunk, shuf_idxes);
idxes = _mm512_maskz_add_epi32(msk_ext, idxes, bytes);
if (size == sizeof(uint16_t)) {
tmp = _mm512_mask_i32gather_epi32(zero, msk_ext,
idxes, (const int *)dp->tbl8, 2);
tmp = _mm512_and_epi32(tmp, res_msk);
} else
tmp = _mm512_mask_i32gather_epi32(zero, msk_ext,
idxes, (const int *)dp->tbl8, 4);
new_msk = _mm512_test_epi32_mask(tmp, lsb);
res = _mm512_mask_blend_epi32(msk_ext ^ new_msk, res, tmp);
tmp = _mm512_srli_epi32(tmp, 1);
msk_ext = new_msk;
shuf_idxes = _mm512_maskz_add_epi8(k, shuf_idxes, lsb);
shuf_idxes = _mm512_and_epi32(shuf_idxes, two_lsb);
shuf_idxes = _mm512_maskz_add_epi8(k, shuf_idxes, base_idxes);
i++;
}
res = _mm512_srli_epi32(res, 1);
tmp = _mm512_maskz_expand_epi32(exp_msk, res);
__m256i tmp256;
tmp256 = _mm512_extracti32x8_epi32(res, 1);
tmp2 = _mm512_maskz_expand_epi32(exp_msk,
_mm512_castsi256_si512(tmp256));
_mm512_storeu_si512(next_hops, tmp);
_mm512_storeu_si512(next_hops + 8, tmp2);
}
static void
trie_vec_lookup_x8_8b(void *p, uint8_t ips[8][RTE_FIB6_IPV6_ADDR_SIZE],
uint64_t *next_hops)
{
struct rte_trie_tbl *dp = (struct rte_trie_tbl *)p;
const __m512i zero = _mm512_set1_epi32(0);
const __m512i lsb = _mm512_set1_epi32(1);
const __m512i three_lsb = _mm512_set1_epi32(7);
__m512i first, second; /*< IPv6 eight byte chunks */
__m512i idxes, res, shuf_idxes;
__m512i tmp, bytes, byte_chunk, base_idxes;
const __rte_x86_zmm_t bswap = {
.u8 = { 2, 1, 0, 255, 255, 255, 255, 255,
10, 9, 8, 255, 255, 255, 255, 255,
2, 1, 0, 255, 255, 255, 255, 255,
10, 9, 8, 255, 255, 255, 255, 255,
2, 1, 0, 255, 255, 255, 255, 255,
10, 9, 8, 255, 255, 255, 255, 255,
2, 1, 0, 255, 255, 255, 255, 255,
10, 9, 8, 255, 255, 255, 255, 255
},
};
const __mmask64 k = 0x101010101010101;
int i = 3;
__mmask8 msk_ext, new_msk;
transpose_x8(ips, &first, &second);
/* get_tbl24_idx() for every 4 byte chunk */
idxes = _mm512_shuffle_epi8(first, bswap.z);
/* lookup in tbl24 */
res = _mm512_i64gather_epi64(idxes, (const void *)dp->tbl24, 8);
/* get extended entries indexes */
msk_ext = _mm512_test_epi64_mask(res, lsb);
tmp = _mm512_srli_epi64(res, 1);
/* idxes to retrieve bytes */
shuf_idxes = _mm512_setr_epi64(3, 11, 19, 27, 35, 43, 51, 59);
base_idxes = _mm512_setr_epi64(0, 8, 16, 24, 32, 40, 48, 56);
/* traverse down the trie */
while (msk_ext) {
idxes = _mm512_maskz_slli_epi64(msk_ext, tmp, 8);
byte_chunk = (i < 8) ? first : second;
bytes = _mm512_maskz_shuffle_epi8(k, byte_chunk, shuf_idxes);
idxes = _mm512_maskz_add_epi64(msk_ext, idxes, bytes);
tmp = _mm512_mask_i64gather_epi64(zero, msk_ext,
idxes, (const void *)dp->tbl8, 8);
new_msk = _mm512_test_epi64_mask(tmp, lsb);
res = _mm512_mask_blend_epi64(msk_ext ^ new_msk, res, tmp);
tmp = _mm512_srli_epi64(tmp, 1);
msk_ext = new_msk;
shuf_idxes = _mm512_maskz_add_epi8(k, shuf_idxes, lsb);
shuf_idxes = _mm512_and_epi64(shuf_idxes, three_lsb);
shuf_idxes = _mm512_maskz_add_epi8(k, shuf_idxes, base_idxes);
i++;
}
res = _mm512_srli_epi64(res, 1);
_mm512_storeu_si512(next_hops, res);
}
void
rte_trie_vec_lookup_bulk_2b(void *p, uint8_t ips[][RTE_FIB6_IPV6_ADDR_SIZE],
uint64_t *next_hops, const unsigned int n)
{
uint32_t i;
for (i = 0; i < (n / 16); i++) {
trie_vec_lookup_x16(p, (uint8_t (*)[16])&ips[i * 16][0],
next_hops + i * 16, sizeof(uint16_t));
}
rte_trie_lookup_bulk_2b(p, (uint8_t (*)[16])&ips[i * 16][0],
next_hops + i * 16, n - i * 16);
}
void
rte_trie_vec_lookup_bulk_4b(void *p, uint8_t ips[][RTE_FIB6_IPV6_ADDR_SIZE],
uint64_t *next_hops, const unsigned int n)
{
uint32_t i;
for (i = 0; i < (n / 16); i++) {
trie_vec_lookup_x16(p, (uint8_t (*)[16])&ips[i * 16][0],
next_hops + i * 16, sizeof(uint32_t));
}
rte_trie_lookup_bulk_4b(p, (uint8_t (*)[16])&ips[i * 16][0],
next_hops + i * 16, n - i * 16);
}
void
rte_trie_vec_lookup_bulk_8b(void *p, uint8_t ips[][RTE_FIB6_IPV6_ADDR_SIZE],
uint64_t *next_hops, const unsigned int n)
{
uint32_t i;
for (i = 0; i < (n / 8); i++) {
trie_vec_lookup_x8_8b(p, (uint8_t (*)[16])&ips[i * 8][0],
next_hops + i * 8);
}
rte_trie_lookup_bulk_8b(p, (uint8_t (*)[16])&ips[i * 8][0],
next_hops + i * 8, n - i * 8);
}