Hi Jerin,
> -----Original Message-----
> From: Jerin Jacob Kollanukkaran <jer...@marvell.com>
> Sent: Monday, February 11, 2019 15:49
> To: Ruifeng Wang (Arm Technology China) <ruifeng.w...@arm.com>;
> yipeng1.w...@intel.com
> Cc: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com>; nd
> <n...@arm.com>; dev@dpdk.org
> Subject: Re: [EXT] [PATCH v1] hash: optimize signature compare by using
> neon intrinsic
>
> On Mon, 2019-02-11 at 15:30 +0800, Ruifeng Wang wrote:
> >
> > -------------------------------------------------------------------
> > ---
> > Implemented signature compare function based on neon intrinsic.
> > Hash bulk lookup had 3% - 6% performance gain after optimization.
> >
> > Signed-off-by: Ruifeng Wang <ruifeng.w...@arm.com>
> > ---
> > lib/librte_hash/rte_cuckoo_hash.c | 32
> > ++++++++++++++++++++++++++++++-
> > lib/librte_hash/rte_cuckoo_hash.h | 1 +
> > 2 files changed, 32 insertions(+), 1 deletion(-)
> >
> > diff --git a/lib/librte_hash/rte_cuckoo_hash.c
> > b/lib/librte_hash/rte_cuckoo_hash.c
> > index c01489ba5..5745a254f 100644
> > --- a/lib/librte_hash/rte_cuckoo_hash.c
> > +++ b/lib/librte_hash/rte_cuckoo_hash.c
> > @@ -26,6 +26,9 @@
> > #include <rte_spinlock.h>
> > #include <rte_ring.h>
> > #include <rte_compat.h>
> > +#if defined(RTE_ARCH_ARM64)
> > +#include <arm_neon.h>
> > +#endif
>
>
> The use of rte_vector.h will remove the need for #if defined...
>
OK. Will change to rte_vect.h in next version.
>
> >
> > #include "rte_hash.h"
> > #include "rte_cuckoo_hash.h"
> > @@ -407,6 +410,10 @@ rte_hash_create(const struct
> rte_hash_parameters
> > *params)
> > if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE2))
> > h->sig_cmp_fn = RTE_HASH_COMPARE_SSE;
> > else
> > +#elif defined(RTE_ARCH_ARM64)
> > + if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_NEON))
> > + h->sig_cmp_fn = RTE_HASH_COMPARE_NEON;
> > + else
> > #endif
> > h->sig_cmp_fn = RTE_HASH_COMPARE_SCALAR;
> >
> > @@ -1578,10 +1585,15 @@ compare_signatures(uint32_t
> > *prim_hash_matches, uint32_t *sec_hash_matches,
> > enum rte_hash_sig_compare_function sig_cmp_fn)
> {
> > unsigned int i;
> > +#ifdef RTE_MACHINE_CPUFLAG_NEON
> > + uint16x8_t vmat, vsig, x;
> > + uint64x2_t x64;
> > + int16x8_t shift = {-15, -13, -11, -9, -7, -5, -3, -1}; #endif
>
> Is it possible move down the variable declaration? to avoid the need for
> #ifdef here
>
Will move down the variable declaration into 'case' block.
> >
> > /* For match mask the first bit of every two bits indicates the
> > match */
> > switch (sig_cmp_fn) {
> > -#ifdef RTE_MACHINE_CPUFLAG_SSE2
> > +#if defined(RTE_MACHINE_CPUFLAG_SSE2)
> > case RTE_HASH_COMPARE_SSE:
> > /* Compare all signatures in the bucket */
> > *prim_hash_matches =
> _mm_movemask_epi8(_mm_cmpeq_epi16(
> > @@ -1594,6 +1606,24 @@ compare_signatures(uint32_t
> *prim_hash_matches,
> > uint32_t *sec_hash_matches,
> > (__m128i const *)sec_bkt-
> > >sig_current),
> > _mm_set1_epi16(sig)));
> > break;
> > +#elif defined(RTE_MACHINE_CPUFLAG_NEON)
> > + case RTE_HASH_COMPARE_NEON:
> > + 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);
> > + x64 = vpaddlq_u32(vpaddlq_u16(x));
> > + *prim_hash_matches = (uint32_t)(vgetq_lane_u64(x64, 0)
> > +
> > + vgetq_lane_u64(x64, 1));
> > + /* 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));
> > + break;
> > #endif
> > default:
> > for (i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) { diff --git
> > a/lib/librte_hash/rte_cuckoo_hash.h
> > b/lib/librte_hash/rte_cuckoo_hash.h
> > index eacdaa8d4..0548c97f0 100644
> > --- a/lib/librte_hash/rte_cuckoo_hash.h
> > +++ b/lib/librte_hash/rte_cuckoo_hash.h
> > @@ -141,6 +141,7 @@ struct rte_hash_key { enum
> > rte_hash_sig_compare_function {
> > RTE_HASH_COMPARE_SCALAR = 0,
> > RTE_HASH_COMPARE_SSE,
> > + RTE_HASH_COMPARE_NEON,
> > RTE_HASH_COMPARE_NUM
> > };
> >
