[dpdk-dev] [PATCH v1] hash: simplify signature compare neon process

[dpdk-dev] [PATCH v1] hash: simplify signature compare neon process

[Ruifeng Wang]

Replaced multiple neon instructions with single equivalent instruction.
This made simpler code and a bit higher performance.
Hash bulk lookup had 0.1% ~ 3% performance gain in tests on ARM A72
platforms.

Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
---
 lib/librte_hash/rte_cuckoo_hash.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/lib/librte_hash/rte_cuckoo_hash.c b/lib/librte_hash/rte_cuckoo_hash.c
index 261267b..f17819e 100644
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -1656,7 +1656,6 @@ compare_signatures(uint32_t *prim_hash_matches, uint32_t *sec_hash_matches,
 #elif defined(RTE_MACHINE_CPUFLAG_NEON)
 	case RTE_HASH_COMPARE_NEON: {
 		uint16x8_t vmat, vsig, x;
-		uint64x2_t x64;
 		int16x8_t shift = {-15, -13, -11, -9, -7, -5, -3, -1};
 
 		vsig = vld1q_dup_u16((uint16_t const *)&sig);
@@ -1664,16 +1663,13 @@ compare_signatures(uint32_t *prim_hash_matches, uint32_t *sec_hash_matches,
 		vmat = vceqq_u16(vsig,
 			vld1q_u16((uint16_t const *)prim_bkt->sig_current));
 		x = vshlq_u16(vandq_u16(vmat, vdupq_n_u16(0x8000)), shift);
-		x64 = vpaddlq_u32(vpaddlq_u16(x));
-		*prim_hash_matches = (uint32_t)(vgetq_lane_u64(x64, 0) +
-			vgetq_lane_u64(x64, 1));
+		*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);
-		x64 = vpaddlq_u32(vpaddlq_u16(x));
-		*sec_hash_matches = (uint32_t)(vgetq_lane_u64(x64, 0) +
-			vgetq_lane_u64(x64, 1)); }
+		*sec_hash_matches = (uint32_t)(vaddvq_u16(x));
+		}
 		break;
 #endif
 	default:
-- 
2.7.4

[dpdk-dev] [PATCH v1] hash: simplify signature compare neon process

[Ruifeng Wang]

Replaced multiple neon instructions with single equivalent instruction.
This made simpler code and a bit higher performance.
Hash bulk lookup had 0.1% ~ 3% performance gain in tests on ARM A72
platforms.

Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
---
 lib/librte_hash/rte_cuckoo_hash.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/lib/librte_hash/rte_cuckoo_hash.c b/lib/librte_hash/rte_cuckoo_hash.c
index 261267b..f17819e 100644
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -1656,7 +1656,6 @@ compare_signatures(uint32_t *prim_hash_matches, uint32_t *sec_hash_matches,
 #elif defined(RTE_MACHINE_CPUFLAG_NEON)
 	case RTE_HASH_COMPARE_NEON: {
 		uint16x8_t vmat, vsig, x;
-		uint64x2_t x64;
 		int16x8_t shift = {-15, -13, -11, -9, -7, -5, -3, -1};
 
 		vsig = vld1q_dup_u16((uint16_t const *)&sig);
@@ -1664,16 +1663,13 @@ compare_signatures(uint32_t *prim_hash_matches, uint32_t *sec_hash_matches,
 		vmat = vceqq_u16(vsig,
 			vld1q_u16((uint16_t const *)prim_bkt->sig_current));
 		x = vshlq_u16(vandq_u16(vmat, vdupq_n_u16(0x8000)), shift);
-		x64 = vpaddlq_u32(vpaddlq_u16(x));
-		*prim_hash_matches = (uint32_t)(vgetq_lane_u64(x64, 0) +
-			vgetq_lane_u64(x64, 1));
+		*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);
-		x64 = vpaddlq_u32(vpaddlq_u16(x));
-		*sec_hash_matches = (uint32_t)(vgetq_lane_u64(x64, 0) +
-			vgetq_lane_u64(x64, 1)); }
+		*sec_hash_matches = (uint32_t)(vaddvq_u16(x));
+		}
 		break;
 #endif
 	default:
-- 
2.7.4

Re: [dpdk-dev] [PATCH v1] hash: simplify signature compare neon process

[Thomas Monjalon]

29/04/2019 12:02, Ruifeng Wang:
> Replaced multiple neon instructions with single equivalent instruction.
> This made simpler code and a bit higher performance.
> Hash bulk lookup had 0.1% ~ 3% performance gain in tests on ARM A72
> platforms.

As it is an improvement (with small benefit), I don't take any risk
for -rc3 and defer it to 19.08.

Re: [dpdk-dev] [PATCH v1] hash: simplify signature compare neon process

[Thomas Monjalon]

29/04/2019 12:02, Ruifeng Wang:
> Replaced multiple neon instructions with single equivalent instruction.
> This made simpler code and a bit higher performance.
> Hash bulk lookup had 0.1% ~ 3% performance gain in tests on ARM A72
> platforms.

As it is an improvement (with small benefit), I don't take any risk
for -rc3 and defer it to 19.08.

Re: [dpdk-dev] [PATCH v1] hash: simplify signature compare neon process

[Wang, Yipeng1]

>-----Original Message-----
>From: Ruifeng Wang [mailto:ruifeng.wang@arm.com]
>Sent: Monday, April 29, 2019 3:02 AM
>To: Wang, Yipeng1 <yipeng1.wang@intel.com>; Gobriel, Sameh <sameh.gobriel@intel.com>; Richardson, Bruce
><bruce.richardson@intel.com>; De Lara Guarch, Pablo <pablo.de.lara.guarch@intel.com>
>Cc: dev@dpdk.org; jerinj@marvell.com; Honnappa.Nagarahalli@arm.com; nd@arm.com; Ruifeng Wang <ruifeng.wang@arm.com>
>Subject: [PATCH v1] hash: simplify signature compare neon process
>
>Replaced multiple neon instructions with single equivalent instruction.
>This made simpler code and a bit higher performance.
>Hash bulk lookup had 0.1% ~ 3% performance gain in tests on ARM A72
>platforms.
>
>Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
>Reviewed-by: Gavin Hu <gavin.hu@arm.com>
>---
[Wang, Yipeng] Sorry for the late review.
The logic seems fine to me based on my understanding of the instructions.
But I don't have an ARM machine to test. Please make sure
It passes the compilation and unit tests.
Or others (Jerin maybe?) could provide more feedback?

Acked-by: Yipeng Wang <yipeng1.wang@intel.com>
 

Re: [dpdk-dev] [PATCH v1] hash: simplify signature compare neon process

[Thomas Monjalon]

> >Replaced multiple neon instructions with single equivalent instruction.
> >This made simpler code and a bit higher performance.
> >Hash bulk lookup had 0.1% ~ 3% performance gain in tests on ARM A72
> >platforms.
> >
> >Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
> >Reviewed-by: Gavin Hu <gavin.hu@arm.com>
> >---
> [Wang, Yipeng] Sorry for the late review.
> The logic seems fine to me based on my understanding of the instructions.
> But I don't have an ARM machine to test. Please make sure
> It passes the compilation and unit tests.
> Or others (Jerin maybe?) could provide more feedback?
> 
> Acked-by: Yipeng Wang <yipeng1.wang@intel.com>
> Reviewed-by: Jerin Jacob <jerinj@marvell.com>

Applied, thanks

Re: [dpdk-dev] [PATCH v1] hash: simplify signature compare neon process

[Jerin Jacob Kollanukkaran]

> -----Original Message-----
> From: Ruifeng Wang <ruifeng.wang@arm.com>
> Sent: Monday, April 29, 2019 3:32 PM
> To: yipeng1.wang@intel.com; sameh.gobriel@intel.com;
> bruce.richardson@intel.com; pablo.de.lara.guarch@intel.com
> Cc: dev@dpdk.org; Jerin Jacob Kollanukkaran <jerinj@marvell.com>;
> Honnappa.Nagarahalli@arm.com; nd@arm.com; Ruifeng Wang
> <ruifeng.wang@arm.com>
> Subject: [EXT] [PATCH v1] hash: simplify signature compare neon process
> 
> Replaced multiple neon instructions with single equivalent instruction.
> This made simpler code and a bit higher performance.
> Hash bulk lookup had 0.1% ~ 3% performance gain in tests on ARM A72
> platforms.
> 
> Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
> Reviewed-by: Gavin Hu <gavin.hu@arm.com>

Reviewed-by: Jerin Jacob <jerinj@marvell.com>