>
> - Implemented SVE code for comparing signatures in bulk lookup.
> - Added Defines in code for SVE code support.
> - Optimise NEON code
> - New SVE code is ~5% slower than optimized NEON for N2 processor.
>
> Signed-off-by: Yoan Picchi <yoan.pic...@arm.com>
> Signed-off-by: Harjot Singh <harjot.si...@arm.com>
> Reviewed-by: Nathan Brown <nathan.br...@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com>
> ---
> lib/hash/rte_cuckoo_hash.c | 196 ++++++++++++++++++++++++++++---------
> lib/hash/rte_cuckoo_hash.h | 1 +
> 2 files changed, 151 insertions(+), 46 deletions(-)
>
> diff --git a/lib/hash/rte_cuckoo_hash.c b/lib/hash/rte_cuckoo_hash.c
> index a07dd3a28d..231d6d6ded 100644
> --- a/lib/hash/rte_cuckoo_hash.c
> +++ b/lib/hash/rte_cuckoo_hash.c
> @@ -442,8 +442,11 @@ rte_hash_create(const struct rte_hash_parameters *params)
> h->sig_cmp_fn = RTE_HASH_COMPARE_SSE;
> else
> #elif defined(RTE_ARCH_ARM64)
> - if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_NEON))
> + if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_NEON)) {
> h->sig_cmp_fn = RTE_HASH_COMPARE_NEON;
> + if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SVE))
> + h->sig_cmp_fn = RTE_HASH_COMPARE_SVE;
> + }
> else
> #endif
> h->sig_cmp_fn = RTE_HASH_COMPARE_SCALAR;
> @@ -1860,37 +1863,103 @@ rte_hash_free_key_with_position(const struct
> rte_hash *h,
> #if defined(__ARM_NEON)
>
> static inline void
> -compare_signatures_dense(uint32_t *prim_hash_matches, uint32_t
> *sec_hash_matches,
> - const struct rte_hash_bucket *prim_bkt,
> - const struct rte_hash_bucket *sec_bkt,
> +compare_signatures_dense(uint16_t *hitmask_buffer,
> + const uint16_t *prim_bucket_sigs,
> + const uint16_t *sec_bucket_sigs,
> uint16_t sig,
> enum rte_hash_sig_compare_function sig_cmp_fn)
> {
> unsigned int i;
>
> + static_assert(sizeof(*hitmask_buffer) >= 2*(RTE_HASH_BUCKET_ENTRIES/8),
> + "The hitmask must be exactly wide enough to accept the whole hitmask if
> it is dense");
> +
> /* For match mask every bits indicates the match */
> switch (sig_cmp_fn) {
Can I ask to move arch specific comparison code into some arch-specific headers
or so?
It is getting really hard to read and understand the generic code with all
these ifdefs and arch specific instructions...
> +#if RTE_HASH_BUCKET_ENTRIES <= 8
> case RTE_HASH_COMPARE_NEON: {
> - uint16x8_t vmat, x;
> + uint16x8_t vmat, hit1, hit2;
> const uint16x8_t mask = {0x1, 0x2, 0x4, 0x8, 0x10, 0x20, 0x40,
> 0x80};
> const uint16x8_t vsig = vld1q_dup_u16((uint16_t const *)&sig);
>
> /* Compare all signatures in the primary bucket */
> - vmat = vceqq_u16(vsig, vld1q_u16((uint16_t const
> *)prim_bkt->sig_current));
> - x = vandq_u16(vmat, mask);
> - *prim_hash_matches = (uint32_t)(vaddvq_u16(x));
> + vmat = vceqq_u16(vsig, vld1q_u16(prim_bucket_sigs));
> + hit1 = vandq_u16(vmat, mask);
> +
> /* Compare all signatures in the secondary bucket */
> - vmat = vceqq_u16(vsig, vld1q_u16((uint16_t const
> *)sec_bkt->sig_current));
> - x = vandq_u16(vmat, mask);
> - *sec_hash_matches = (uint32_t)(vaddvq_u16(x));
> + vmat = vceqq_u16(vsig, vld1q_u16(sec_bucket_sigs));
> + hit2 = vandq_u16(vmat, mask);
> +
> + hit2 = vshlq_n_u16(hit2, RTE_HASH_BUCKET_ENTRIES);
> + hit2 = vorrq_u16(hit1, hit2);
> + *hitmask_buffer = vaddvq_u16(hit2);
> + }
> + break;
> +#endif
> +#if defined(RTE_HAS_SVE_ACLE)
> + case RTE_HASH_COMPARE_SVE: {
> + svuint16_t vsign, shift, sv_matches;
> + svbool_t pred, match, bucket_wide_pred;
> + int i = 0;
> + uint64_t vl = svcnth();
> +
> + vsign = svdup_u16(sig);
> + shift = svindex_u16(0, 1);
> +
> + if (vl >= 2 * RTE_HASH_BUCKET_ENTRIES &&
> RTE_HASH_BUCKET_ENTRIES <= 8) {
> + svuint16_t primary_array_vect, secondary_array_vect;
> + bucket_wide_pred = svwhilelt_b16(0,
> RTE_HASH_BUCKET_ENTRIES);
> + primary_array_vect = svld1_u16(bucket_wide_pred,
> prim_bucket_sigs);
> + secondary_array_vect = svld1_u16(bucket_wide_pred,
> sec_bucket_sigs);
> +
> + /* We merged the two vectors so we can do both
> comparison at once */
> + primary_array_vect = svsplice_u16(bucket_wide_pred,
> + primary_array_vect,
> + secondary_array_vect);
> + pred = svwhilelt_b16(0, 2*RTE_HASH_BUCKET_ENTRIES);
> +
> + /* Compare all signatures in the buckets */
> + match = svcmpeq_u16(pred, vsign, primary_array_vect);
> + if (svptest_any(svptrue_b16(), match)) {
> + sv_matches = svdup_u16(1);
> + sv_matches = svlsl_u16_z(match, sv_matches,
> shift);
> + *hitmask_buffer = svorv_u16(svptrue_b16(),
> sv_matches);
> + }
> + } else {
> + do {
> + pred = svwhilelt_b16(i,
> RTE_HASH_BUCKET_ENTRIES);
> + uint16_t lower_half = 0;
> + uint16_t upper_half = 0;
> + /* Compare all signatures in the primary bucket
> */
> + match = svcmpeq_u16(pred, vsign, svld1_u16(pred,
> + &prim_bucket_sigs[i]));
> + if (svptest_any(svptrue_b16(), match)) {
> + sv_matches = svdup_u16(1);
> + sv_matches = svlsl_u16_z(match,
> sv_matches, shift);
> + lower_half = svorv_u16(svptrue_b16(),
> sv_matches);
> + }
> + /* Compare all signatures in the secondary
> bucket */
> + match = svcmpeq_u16(pred, vsign, svld1_u16(pred,
> + &sec_bucket_sigs[i]));
> + if (svptest_any(svptrue_b16(), match)) {
> + sv_matches = svdup_u16(1);
> + sv_matches = svlsl_u16_z(match,
> sv_matches, shift);
> + upper_half = svorv_u16(svptrue_b16(),
> sv_matches)
> + << RTE_HASH_BUCKET_ENTRIES;
> + }
> + hitmask_buffer[i/8] = upper_half | lower_half;
> + i += vl;
> + } while (i < RTE_HASH_BUCKET_ENTRIES);
> + }
> }
> break;
> +#endif
> default:
> for (i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) {
> - *prim_hash_matches |=
> - ((sig == prim_bkt->sig_current[i]) << i);
> - *sec_hash_matches |=
> - ((sig == sec_bkt->sig_current[i]) << i);
> + *hitmask_buffer |=
> + ((sig == prim_bucket_sigs[i]) << i);
> + *hitmask_buffer |=
> + ((sig == sec_bucket_sigs[i]) << i) <<
> RTE_HASH_BUCKET_ENTRIES;
> }
> }
> }
> @@ -1908,7 +1977,7 @@ compare_signatures_sparse(uint32_t *prim_hash_matches,
> uint32_t *sec_hash_matche
>
> /* For match mask the first bit of every two bits indicates the match */
> switch (sig_cmp_fn) {
> -#if defined(__SSE2__)
> +#if defined(__SSE2__) && RTE_HASH_BUCKET_ENTRIES <= 8
> case RTE_HASH_COMPARE_SSE:
> /* Compare all signatures in the bucket */
> *prim_hash_matches = _mm_movemask_epi8(_mm_cmpeq_epi16(
> @@ -1948,14 +2017,18 @@ __bulk_lookup_l(const struct rte_hash *h, const void
> **keys,
> uint64_t hits = 0;
> int32_t i;
> int32_t ret;
> - uint32_t prim_hitmask[RTE_HASH_LOOKUP_BULK_MAX] = {0};
> - uint32_t sec_hitmask[RTE_HASH_LOOKUP_BULK_MAX] = {0};
> struct rte_hash_bucket *cur_bkt, *next_bkt;
>
> #if defined(__ARM_NEON)
> const int hitmask_padding = 0;
> + uint16_t hitmask_buffer[RTE_HASH_LOOKUP_BULK_MAX] = {0};
> +
> + static_assert(sizeof(*hitmask_buffer)*8/2 == RTE_HASH_BUCKET_ENTRIES,
> + "The hitmask must be exactly wide enough to accept the whole hitmask
> when it is dense");
> #else
> const int hitmask_padding = 1;
> + uint32_t prim_hitmask_buffer[RTE_HASH_LOOKUP_BULK_MAX] = {0};
> + uint32_t sec_hitmask_buffer[RTE_HASH_LOOKUP_BULK_MAX] = {0};
> #endif
>
> __hash_rw_reader_lock(h);
> @@ -1963,18 +2036,24 @@ __bulk_lookup_l(const struct rte_hash *h, const void
> **keys,
> /* Compare signatures and prefetch key slot of first hit */
> for (i = 0; i < num_keys; i++) {
> #if defined(__ARM_NEON)
> - compare_signatures_dense(&prim_hitmask[i], &sec_hitmask[i],
> - primary_bkt[i], secondary_bkt[i],
> + uint16_t *hitmask = &hitmask_buffer[i];
> + compare_signatures_dense(hitmask,
> + primary_bkt[i]->sig_current,
> + secondary_bkt[i]->sig_current,
> sig[i], h->sig_cmp_fn);
> + const unsigned int prim_hitmask = *(uint8_t *)(hitmask);
> + const unsigned int sec_hitmask = *((uint8_t *)(hitmask)+1);
> #else
> - compare_signatures_sparse(&prim_hitmask[i], &sec_hitmask[i],
> + compare_signatures_sparse(&prim_hitmask_buffer[i],
> &sec_hitmask_buffer[i],
> primary_bkt[i], secondary_bkt[i],
> sig[i], h->sig_cmp_fn);
> + const unsigned int prim_hitmask = prim_hitmask_buffer[i];
> + const unsigned int sec_hitmask = sec_hitmask_buffer[i];
> #endif
>
> - if (prim_hitmask[i]) {
> + if (prim_hitmask) {
> uint32_t first_hit =
> - rte_ctz32(prim_hitmask[i])
> + rte_ctz32(prim_hitmask)
> >> hitmask_padding;
> uint32_t key_idx =
> primary_bkt[i]->key_idx[first_hit];
> @@ -1986,9 +2065,9 @@ __bulk_lookup_l(const struct rte_hash *h, const void
> **keys,
> continue;
> }
>
> - if (sec_hitmask[i]) {
> + if (sec_hitmask) {
> uint32_t first_hit =
> - rte_ctz32(sec_hitmask[i])
> + rte_ctz32(sec_hitmask)
> >> hitmask_padding;
> uint32_t key_idx =
> secondary_bkt[i]->key_idx[first_hit];
> @@ -2003,9 +2082,17 @@ __bulk_lookup_l(const struct rte_hash *h, const void
> **keys,
> /* Compare keys, first hits in primary first */
> for (i = 0; i < num_keys; i++) {
> positions[i] = -ENOENT;
> - while (prim_hitmask[i]) {
> +#if defined(__ARM_NEON)
> + uint16_t *hitmask = &hitmask_buffer[i];
> + unsigned int prim_hitmask = *(uint8_t *)(hitmask);
> + unsigned int sec_hitmask = *((uint8_t *)(hitmask)+1);
> +#else
> + unsigned int prim_hitmask = prim_hitmask_buffer[i];
> + unsigned int sec_hitmask = sec_hitmask_buffer[i];
> +#endif
> + while (prim_hitmask) {
> uint32_t hit_index =
> - rte_ctz32(prim_hitmask[i])
> + rte_ctz32(prim_hitmask)
> >> hitmask_padding;
> uint32_t key_idx =
> primary_bkt[i]->key_idx[hit_index];
> @@ -2028,12 +2115,12 @@ __bulk_lookup_l(const struct rte_hash *h, const void
> **keys,
> positions[i] = key_idx - 1;
> goto next_key;
> }
> - prim_hitmask[i] &= ~(1 << (hit_index <<
> hitmask_padding));
> + prim_hitmask &= ~(1 << (hit_index << hitmask_padding));
> }
>
> - while (sec_hitmask[i]) {
> + while (sec_hitmask) {
> uint32_t hit_index =
> - rte_ctz32(sec_hitmask[i])
> + rte_ctz32(sec_hitmask)
> >> hitmask_padding;
> uint32_t key_idx =
> secondary_bkt[i]->key_idx[hit_index];
> @@ -2057,7 +2144,7 @@ __bulk_lookup_l(const struct rte_hash *h, const void
> **keys,
> positions[i] = key_idx - 1;
> goto next_key;
> }
> - sec_hitmask[i] &= ~(1 << (hit_index <<
> hitmask_padding));
> + sec_hitmask &= ~(1 << (hit_index << hitmask_padding));
> }
> next_key:
> continue;
> @@ -2107,15 +2194,18 @@ __bulk_lookup_lf(const struct rte_hash *h, const void
> **keys,
> uint64_t hits = 0;
> int32_t i;
> int32_t ret;
> - uint32_t prim_hitmask[RTE_HASH_LOOKUP_BULK_MAX] = {0};
> - uint32_t sec_hitmask[RTE_HASH_LOOKUP_BULK_MAX] = {0};
> struct rte_hash_bucket *cur_bkt, *next_bkt;
> uint32_t cnt_b, cnt_a;
>
> #if defined(__ARM_NEON)
> const int hitmask_padding = 0;
> + uint16_t hitmask_buffer[RTE_HASH_LOOKUP_BULK_MAX] = {0};
> + static_assert(sizeof(*hitmask_buffer)*8/2 == RTE_HASH_BUCKET_ENTRIES,
> + "The hitmask must be exactly wide enough to accept the whole hitmask
> chen it is dense");
> #else
> const int hitmask_padding = 1;
> + uint32_t prim_hitmask_buffer[RTE_HASH_LOOKUP_BULK_MAX] = {0};
> + uint32_t sec_hitmask_buffer[RTE_HASH_LOOKUP_BULK_MAX] = {0};
> #endif
>
> for (i = 0; i < num_keys; i++)
> @@ -2132,18 +2222,24 @@ __bulk_lookup_lf(const struct rte_hash *h, const void
> **keys,
> /* Compare signatures and prefetch key slot of first hit */
> for (i = 0; i < num_keys; i++) {
> #if defined(__ARM_NEON)
> - compare_signatures_dense(&prim_hitmask[i],
> &sec_hitmask[i],
> - primary_bkt[i], secondary_bkt[i],
> + uint16_t *hitmask = &hitmask_buffer[i];
> + compare_signatures_dense(hitmask,
> + primary_bkt[i]->sig_current,
> + secondary_bkt[i]->sig_current,
> sig[i], h->sig_cmp_fn);
> + const unsigned int prim_hitmask = *(uint8_t *)(hitmask);
> + const unsigned int sec_hitmask = *((uint8_t
> *)(hitmask)+1);
> #else
> - compare_signatures_sparse(&prim_hitmask[i],
> &sec_hitmask[i],
> + compare_signatures_sparse(&prim_hitmask_buffer[i],
> &sec_hitmask_buffer[i],
> primary_bkt[i], secondary_bkt[i],
> sig[i], h->sig_cmp_fn);
> + const unsigned int prim_hitmask =
> prim_hitmask_buffer[i];
> + const unsigned int sec_hitmask = sec_hitmask_buffer[i];
> #endif
>
> - if (prim_hitmask[i]) {
> + if (prim_hitmask) {
> uint32_t first_hit =
> - rte_ctz32(prim_hitmask[i])
> + rte_ctz32(prim_hitmask)
> >> hitmask_padding;
> uint32_t key_idx =
> primary_bkt[i]->key_idx[first_hit];
> @@ -2155,9 +2251,9 @@ __bulk_lookup_lf(const struct rte_hash *h, const void
> **keys,
> continue;
> }
>
> - if (sec_hitmask[i]) {
> + if (sec_hitmask) {
> uint32_t first_hit =
> - rte_ctz32(sec_hitmask[i])
> + rte_ctz32(sec_hitmask)
> >> hitmask_padding;
> uint32_t key_idx =
> secondary_bkt[i]->key_idx[first_hit];
> @@ -2171,9 +2267,17 @@ __bulk_lookup_lf(const struct rte_hash *h, const void
> **keys,
>
> /* Compare keys, first hits in primary first */
> for (i = 0; i < num_keys; i++) {
> - while (prim_hitmask[i]) {
> +#if defined(__ARM_NEON)
> + uint16_t *hitmask = &hitmask_buffer[i];
> + unsigned int prim_hitmask = *(uint8_t *)(hitmask);
> + unsigned int sec_hitmask = *((uint8_t *)(hitmask)+1);
> +#else
> + unsigned int prim_hitmask = prim_hitmask_buffer[i];
> + unsigned int sec_hitmask = sec_hitmask_buffer[i];
> +#endif
> + while (prim_hitmask) {
> uint32_t hit_index =
> - rte_ctz32(prim_hitmask[i])
> + rte_ctz32(prim_hitmask)
> >> hitmask_padding;
> uint32_t key_idx =
> rte_atomic_load_explicit(
> @@ -2200,12 +2304,12 @@ __bulk_lookup_lf(const struct rte_hash *h, const void
> **keys,
> positions[i] = key_idx - 1;
> goto next_key;
> }
> - prim_hitmask[i] &= ~(1 << (hit_index <<
> hitmask_padding));
> + prim_hitmask &= ~(1 << (hit_index <<
> hitmask_padding));
> }
>
> - while (sec_hitmask[i]) {
> + while (sec_hitmask) {
> uint32_t hit_index =
> - rte_ctz32(sec_hitmask[i])
> + rte_ctz32(sec_hitmask)
> >> hitmask_padding;
> uint32_t key_idx =
> rte_atomic_load_explicit(
> @@ -2233,7 +2337,7 @@ __bulk_lookup_lf(const struct rte_hash *h, const void
> **keys,
> positions[i] = key_idx - 1;
> goto next_key;
> }
> - sec_hitmask[i] &= ~(1 << (hit_index <<
> hitmask_padding));
> + sec_hitmask &= ~(1 << (hit_index <<
> hitmask_padding));
> }
> next_key:
> continue;
> diff --git a/lib/hash/rte_cuckoo_hash.h b/lib/hash/rte_cuckoo_hash.h
> index 8ea793c66e..ed18e1f41e 100644
> --- a/lib/hash/rte_cuckoo_hash.h
> +++ b/lib/hash/rte_cuckoo_hash.h
> @@ -137,6 +137,7 @@ enum rte_hash_sig_compare_function {
> RTE_HASH_COMPARE_SCALAR = 0,
> RTE_HASH_COMPARE_SSE,
> RTE_HASH_COMPARE_NEON,
> + RTE_HASH_COMPARE_SVE,
> RTE_HASH_COMPARE_NUM
> };
>
> --
> 2.34.1
