/* SPDX-License-Identifier: GPL-2.0 */
/*
* NH - ε-almost-universal hash function, NEON accelerated version
*
* Copyright 2018 Google LLC
*
* Author: Eric Biggers <[email protected]>
*/
#include <linux/linkage.h>
.text
.fpu neon
KEY .req r0
MESSAGE .req r1
MESSAGE_LEN .req r2
HASH .req r3
PASS0_SUMS .req q0
PASS0_SUM_A .req d0
PASS0_SUM_B .req d1
PASS1_SUMS .req q1
PASS1_SUM_A .req d2
PASS1_SUM_B .req d3
PASS2_SUMS .req q2
PASS2_SUM_A .req d4
PASS2_SUM_B .req d5
PASS3_SUMS .req q3
PASS3_SUM_A .req d6
PASS3_SUM_B .req d7
K0 .req q4
K1 .req q5
K2 .req q6
K3 .req q7
T0 .req q8
T0_L .req d16
T0_H .req d17
T1 .req q9
T1_L .req d18
T1_H .req d19
T2 .req q10
T2_L .req d20
T2_H .req d21
T3 .req q11
T3_L .req d22
T3_H .req d23
.macro _nh_stride k0, k1, k2, k3
// Load next message stride
vld1.8 {T3}, [MESSAGE]!
// Load next key stride
vld1.32 {\k3}, [KEY]!
// Add message words to key words
vadd.u32 T0, T3, \k0
vadd.u32 T1, T3, \k1
vadd.u32 T2, T3, \k2
vadd.u32 T3, T3, \k3
// Multiply 32x32 => 64 and accumulate
vmlal.u32 PASS0_SUMS, T0_L, T0_H
vmlal.u32 PASS1_SUMS, T1_L, T1_H
vmlal.u32 PASS2_SUMS, T2_L, T2_H
vmlal.u32 PASS3_SUMS, T3_L, T3_H
.endm
/*
* void nh_neon(const u32 *key, const u8 *message, size_t message_len,
* __le64 hash[NH_NUM_PASSES])
*
* It's guaranteed that message_len % 16 == 0.
*/
ENTRY(nh_neon)
vld1.32 {K0,K1}, [KEY]!
vmov.u64 PASS0_SUMS, #0
vmov.u64 PASS1_SUMS, #0
vld1.32 {K2}, [KEY]!
vmov.u64 PASS2_SUMS, #0
vmov.u64 PASS3_SUMS, #0
subs MESSAGE_LEN, MESSAGE_LEN, #64
blt .Lloop4_done
.Lloop4:
_nh_stride K0, K1, K2, K3
_nh_stride K1, K2, K3, K0
_nh_stride K2, K3, K0, K1
_nh_stride K3, K0, K1, K2
subs MESSAGE_LEN, MESSAGE_LEN, #64
bge .Lloop4
.Lloop4_done:
ands MESSAGE_LEN, MESSAGE_LEN, #63
beq .Ldone
_nh_stride K0, K1, K2, K3
subs MESSAGE_LEN, MESSAGE_LEN, #16
beq .Ldone
_nh_stride K1, K2, K3, K0
subs MESSAGE_LEN, MESSAGE_LEN, #16
beq .Ldone
_nh_stride K2, K3, K0, K1
.Ldone:
// Sum the accumulators for each pass, then store the sums to 'hash'
vadd.u64 T0_L, PASS0_SUM_A, PASS0_SUM_B
vadd.u64 T0_H, PASS1_SUM_A, PASS1_SUM_B
vadd.u64 T1_L, PASS2_SUM_A, PASS2_SUM_B
vadd.u64 T1_H, PASS3_SUM_A, PASS3_SUM_B
vst1.8 {T0-T1}, [HASH]
bx lr
ENDPROC(nh_neon)
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