Current hitmask includes padding due to Intel's SIMD
implementation detail. This patch allows non Intel SIMD
implementations to benefit from a dense hitmask.
In addition, the new dense hitmask interweave the primary
and secondary matches which allow a better cache usage and
enable future improvements for the SIMD implementations
The default non SIMD path now use this dense mask.
Signed-off-by: Yoan Picchi <yoan.pic...@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com>
Reviewed-by: Nathan Brown <nathan.br...@arm.com>
---
.mailmap | 2 +
lib/hash/arch/arm/compare_signatures.h | 61 +++++++
lib/hash/arch/common/compare_signatures.h | 37 +++++
lib/hash/arch/x86/compare_signatures.h | 53 ++++++
lib/hash/rte_cuckoo_hash.c | 192 ++++++++++++----------
5 files changed, 254 insertions(+), 91 deletions(-)
create mode 100644 lib/hash/arch/arm/compare_signatures.h
create mode 100644 lib/hash/arch/common/compare_signatures.h
create mode 100644 lib/hash/arch/x86/compare_signatures.h
diff --git a/.mailmap b/.mailmap
index 66ebc20666..00b50414d3 100644
--- a/.mailmap
+++ b/.mailmap
@@ -494,6 +494,7 @@ Hari Kumar Vemula <hari.kumarx.vem...@intel.com>
Harini Ramakrishnan <harini.ramakrish...@microsoft.com>
Hariprasad Govindharajan <hariprasad.govindhara...@intel.com>
Harish Patil <harish.pa...@cavium.com> <harish.pa...@qlogic.com>
+Harjot Singh <harjot.si...@arm.com>
Harman Kalra <hka...@marvell.com>
Harneet Singh <harneet.si...@intel.com>
Harold Huang <baymaxhu...@gmail.com>
@@ -1633,6 +1634,7 @@ Yixue Wang <yixue.w...@intel.com>
Yi Yang <yangy...@inspur.com> <yi.y.y...@intel.com>
Yi Zhang <zhang.y...@zte.com.cn>
Yoann Desmouceaux <ydesm...@cisco.com>
+Yoan Picchi <yoan.pic...@arm.com>
Yogesh Jangra <yogesh.jan...@intel.com>
Yogev Chaimovich <yo...@cgstowernetworks.com>
Yongjie Gu <yongjiex...@intel.com>
diff --git a/lib/hash/arch/arm/compare_signatures.h
b/lib/hash/arch/arm/compare_signatures.h
new file mode 100644
index 0000000000..46d15da89f
--- /dev/null
+++ b/lib/hash/arch/arm/compare_signatures.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2016 Intel Corporation
+ * Copyright(c) 2018-2024 Arm Limited
+ */
+
+/*
+ * Arm's version uses a densely packed hitmask buffer:
+ * Every bit is in use.
+ */
+
+#include <inttypes.h>
+#include <rte_common.h>
+#include <rte_vect.h>
+#include "rte_cuckoo_hash.h"
+
+#define DENSE_HASH_BULK_LOOKUP 1
+
+static inline void
+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)
+{
+
+ static_assert(sizeof(*hitmask_buffer) >= 2 * (RTE_HASH_BUCKET_ENTRIES /
8),
+ "hitmask_buffer must be wide enough to fit a
dense hitmask");
+
+ /* For match mask every bits indicates the match */
+ switch (sig_cmp_fn) {
+#if RTE_HASH_BUCKET_ENTRIES <= 8
+ case RTE_HASH_COMPARE_NEON: {
+ uint16x8_t vmat, vsig, x;
+ int16x8_t shift = {0, 1, 2, 3, 4, 5, 6, 7};
+ uint16_t low, high;
+
+ 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_bucket_sigs));
+ x = vshlq_u16(vandq_u16(vmat, vdupq_n_u16(0x0001)), shift);
+ low = (uint16_t)(vaddvq_u16(x));
+ /* Compare all signatures in the secondary bucket */
+ vmat = vceqq_u16(vsig,
+ vld1q_u16((uint16_t const *)sec_bucket_sigs));
+ x = vshlq_u16(vandq_u16(vmat, vdupq_n_u16(0x0001)), shift);
+ high = (uint16_t)(vaddvq_u16(x));
+ *hitmask_buffer = low | high << RTE_HASH_BUCKET_ENTRIES;
+
+ }
+ break;
+#endif
+ default:
+ for (unsigned int i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) {
+ *hitmask_buffer |=
+ (sig == prim_bucket_sigs[i]) << i;
+ *hitmask_buffer |=
+ ((sig == sec_bucket_sigs[i]) << i) <<
RTE_HASH_BUCKET_ENTRIES;
+ }
+ }
+}
diff --git a/lib/hash/arch/common/compare_signatures.h
b/lib/hash/arch/common/compare_signatures.h
new file mode 100644
index 0000000000..f43b367005
--- /dev/null
+++ b/lib/hash/arch/common/compare_signatures.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2016 Intel Corporation
+ * Copyright(c) 2018-2024 Arm Limited
+ */
+
+/*
+ * The generic version could use either a dense or sparsely packed hitmask
buffer,
+ * but the dense one is slightly faster.
+ */
+
+#include <inttypes.h>
+#include <rte_common.h>
+#include <rte_vect.h>
+#include "rte_cuckoo_hash.h"
+
+#define DENSE_HASH_BULK_LOOKUP 1
+
+static inline void
+compare_signatures_dense(uint16_t *hitmask_buffer,
+ const uint16_t *prim_bucket_sigs,
+ const uint16_t *sec_bucket_sigs,
+ uint16_t sig,
+ __rte_unused enum rte_hash_sig_compare_function
sig_cmp_fn)
+{
+
+ static_assert(sizeof(*hitmask_buffer) >= 2 * (RTE_HASH_BUCKET_ENTRIES /
8),
+ "hitmask_buffer must be wide enough to fit a
dense hitmask");
+
+ /* For match mask every bits indicates the match */
+ for (unsigned int i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) {
+ *hitmask_buffer |=
+ (sig == prim_bucket_sigs[i]) << i;
+ *hitmask_buffer |=
+ ((sig == sec_bucket_sigs[i]) << i) <<
RTE_HASH_BUCKET_ENTRIES;
+ }
+
+}
diff --git a/lib/hash/arch/x86/compare_signatures.h
b/lib/hash/arch/x86/compare_signatures.h
new file mode 100644
index 0000000000..db342804e1
--- /dev/null
+++ b/lib/hash/arch/x86/compare_signatures.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2016 Intel Corporation
+ * Copyright(c) 2018-2024 Arm Limited
+ */
+
+/*
+ * x86's version uses a sparsely packed hitmask buffer:
+ * Every other bit is padding.
+ */
+
+#include <inttypes.h>
+#include <rte_common.h>
+#include <rte_vect.h>
+#include "rte_cuckoo_hash.h"
+
+#define DENSE_HASH_BULK_LOOKUP 0
+
+static inline void
+compare_signatures_sparse(uint32_t *prim_hash_matches, uint32_t
*sec_hash_matches,
+ const struct rte_hash_bucket *prim_bkt,
+ const struct rte_hash_bucket *sec_bkt,
+ uint16_t sig,
+ enum rte_hash_sig_compare_function sig_cmp_fn)
+{
+ /* For match mask the first bit of every two bits indicates the match */
+ switch (sig_cmp_fn) {
+#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(
+ _mm_load_si128(
+ (__m128i const *)prim_bkt->sig_current),
+ _mm_set1_epi16(sig)));
+ /* Extract the even-index bits only */
+ *prim_hash_matches &= 0x5555;
+ /* Compare all signatures in the bucket */
+ *sec_hash_matches = _mm_movemask_epi8(_mm_cmpeq_epi16(
+ _mm_load_si128(
+ (__m128i const *)sec_bkt->sig_current),
+ _mm_set1_epi16(sig)));
+ /* Extract the even-index bits only */
+ *sec_hash_matches &= 0x5555;
+ break;
+#endif /* defined(__SSE2__) */
+ default:
+ for (unsigned int i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) {
+ *prim_hash_matches |=
+ (sig == prim_bkt->sig_current[i]) << (i << 1);
+ *sec_hash_matches |=
+ (sig == sec_bkt->sig_current[i]) << (i << 1);
+ }
+ }
+}
diff --git a/lib/hash/rte_cuckoo_hash.c b/lib/hash/rte_cuckoo_hash.c
index 9cf94645f6..0697743cdf 100644
--- a/lib/hash/rte_cuckoo_hash.c
+++ b/lib/hash/rte_cuckoo_hash.c
@@ -33,6 +33,14 @@ RTE_LOG_REGISTER_DEFAULT(hash_logtype, INFO);
#include "rte_cuckoo_hash.h"
+#if defined(__ARM_NEON)
+#include "arch/arm/compare_signatures.h"
+#elif defined(__SSE2__)
+#include "arch/x86/compare_signatures.h"
+#else
+#include "arch/common/compare_signatures.h"
+#endif
+
/* Mask of all flags supported by this version */
#define RTE_HASH_EXTRA_FLAGS_MASK (RTE_HASH_EXTRA_FLAGS_TRANS_MEM_SUPPORT | \
RTE_HASH_EXTRA_FLAGS_MULTI_WRITER_ADD | \
@@ -1857,63 +1865,6 @@ rte_hash_free_key_with_position(const struct rte_hash *h,
}
-static inline void
-compare_signatures(uint32_t *prim_hash_matches, uint32_t *sec_hash_matches,
- const struct rte_hash_bucket *prim_bkt,
- const struct rte_hash_bucket *sec_bkt,
- uint16_t sig,
- enum rte_hash_sig_compare_function sig_cmp_fn)
-{
- unsigned int i;
-
- /* For match mask the first bit of every two bits indicates the match */
- switch (sig_cmp_fn) {
-#if defined(__SSE2__)
- case RTE_HASH_COMPARE_SSE:
- /* Compare all signatures in the bucket */
- *prim_hash_matches = _mm_movemask_epi8(_mm_cmpeq_epi16(
- _mm_load_si128(
- (__m128i const *)prim_bkt->sig_current),
- _mm_set1_epi16(sig)));
- /* Extract the even-index bits only */
- *prim_hash_matches &= 0x5555;
- /* Compare all signatures in the bucket */
- *sec_hash_matches = _mm_movemask_epi8(_mm_cmpeq_epi16(
- _mm_load_si128(
- (__m128i const *)sec_bkt->sig_current),
- _mm_set1_epi16(sig)));
- /* Extract the even-index bits only */
- *sec_hash_matches &= 0x5555;
- break;
-#elif defined(__ARM_NEON)
- case RTE_HASH_COMPARE_NEON: {
- uint16x8_t vmat, vsig, x;
- int16x8_t shift = {-15, -13, -11, -9, -7, -5, -3, -1};
-
- 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 = vshlq_u16(vandq_u16(vmat, vdupq_n_u16(0x8000)), shift);
- *prim_hash_matches = (uint32_t)(vaddvq_u16(x));
- /* Compare all signatures in the secondary bucket */
- vmat = vceqq_u16(vsig,
- vld1q_u16((uint16_t const *)sec_bkt->sig_current));
- x = vshlq_u16(vandq_u16(vmat, vdupq_n_u16(0x8000)), shift);
- *sec_hash_matches = (uint32_t)(vaddvq_u16(x));
- }
- break;
-#endif
- default:
- for (i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) {
- *prim_hash_matches |=
- ((sig == prim_bkt->sig_current[i]) << (i << 1));
- *sec_hash_matches |=
- ((sig == sec_bkt->sig_current[i]) << (i << 1));
- }
- }
-}
-
static inline void
__bulk_lookup_l(const struct rte_hash *h, const void **keys,
const struct rte_hash_bucket **primary_bkt,
@@ -1924,22 +1875,44 @@ __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 DENSE_HASH_BULK_LOOKUP
+ 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);
/* Compare signatures and prefetch key slot of first hit */
for (i = 0; i < num_keys; i++) {
- compare_signatures(&prim_hitmask[i], &sec_hitmask[i],
+#if DENSE_HASH_BULK_LOOKUP
+ 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_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])
- >> 1;
+ rte_ctz32(prim_hitmask)
+ >> hitmask_padding;
uint32_t key_idx =
primary_bkt[i]->key_idx[first_hit];
const struct rte_hash_key *key_slot =
@@ -1950,10 +1923,10 @@ __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])
- >> 1;
+ rte_ctz32(sec_hitmask)
+ >> hitmask_padding;
uint32_t key_idx =
secondary_bkt[i]->key_idx[first_hit];
const struct rte_hash_key *key_slot =
@@ -1967,10 +1940,18 @@ __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 DENSE_HASH_BULK_LOOKUP
+ 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])
- >> 1;
+ rte_ctz32(prim_hitmask)
+ >> hitmask_padding;
uint32_t key_idx =
primary_bkt[i]->key_idx[hit_index];
const struct rte_hash_key *key_slot =
@@ -1992,13 +1973,13 @@ __bulk_lookup_l(const struct rte_hash *h, const void
**keys,
positions[i] = key_idx - 1;
goto next_key;
}
- prim_hitmask[i] &= ~(3ULL << (hit_index << 1));
+ prim_hitmask &= ~(1 << (hit_index << hitmask_padding));
}
- while (sec_hitmask[i]) {
+ while (sec_hitmask) {
uint32_t hit_index =
- rte_ctz32(sec_hitmask[i])
- >> 1;
+ rte_ctz32(sec_hitmask)
+ >> hitmask_padding;
uint32_t key_idx =
secondary_bkt[i]->key_idx[hit_index];
const struct rte_hash_key *key_slot =
@@ -2021,7 +2002,7 @@ __bulk_lookup_l(const struct rte_hash *h, const void
**keys,
positions[i] = key_idx - 1;
goto next_key;
}
- sec_hitmask[i] &= ~(3ULL << (hit_index << 1));
+ sec_hitmask &= ~(1 << (hit_index << hitmask_padding));
}
next_key:
continue;
@@ -2071,11 +2052,20 @@ __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 DENSE_HASH_BULK_LOOKUP
+ 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++)
positions[i] = -ENOENT;
@@ -2089,14 +2079,26 @@ __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++) {
- compare_signatures(&prim_hitmask[i], &sec_hitmask[i],
+#if DENSE_HASH_BULK_LOOKUP
+ 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_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])
- >> 1;
+ rte_ctz32(prim_hitmask)
+ >> hitmask_padding;
uint32_t key_idx =
primary_bkt[i]->key_idx[first_hit];
const struct rte_hash_key *key_slot =
@@ -2107,10 +2109,10 @@ __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])
- >> 1;
+ rte_ctz32(sec_hitmask)
+ >> hitmask_padding;
uint32_t key_idx =
secondary_bkt[i]->key_idx[first_hit];
const struct rte_hash_key *key_slot =
@@ -2123,10 +2125,18 @@ __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 DENSE_HASH_BULK_LOOKUP
+ 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])
- >> 1;
+ rte_ctz32(prim_hitmask)
+ >> hitmask_padding;
uint32_t key_idx =
rte_atomic_load_explicit(
&primary_bkt[i]->key_idx[hit_index],
@@ -2152,13 +2162,13 @@ __bulk_lookup_lf(const struct rte_hash *h, const void
**keys,
positions[i] = key_idx - 1;
goto next_key;
}
- prim_hitmask[i] &= ~(3ULL << (hit_index << 1));
+ prim_hitmask &= ~(1 << (hit_index <<
hitmask_padding));
}
- while (sec_hitmask[i]) {
+ while (sec_hitmask) {
uint32_t hit_index =
- rte_ctz32(sec_hitmask[i])
- >> 1;
+ rte_ctz32(sec_hitmask)
+ >> hitmask_padding;
uint32_t key_idx =
rte_atomic_load_explicit(
&secondary_bkt[i]->key_idx[hit_index],
@@ -2185,7 +2195,7 @@ __bulk_lookup_lf(const struct rte_hash *h, const void
**keys,
positions[i] = key_idx - 1;
goto next_key;
}
- sec_hitmask[i] &= ~(3ULL << (hit_index << 1));
+ sec_hitmask &= ~(1 << (hit_index <<
hitmask_padding));
}
next_key:
continue;
--
2.25.1
