tzhash/tz/avx2_amd64.s
Evgenii Stratonikov d4cb61e470 Replace two shifts with a single AND
We need to isolate HSB in every quad-word, this can be done with a
simple mask.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-01-17 17:18:36 +03:00

76 lines
1.8 KiB
ArmAsm

#include "textflag.h"
#define mask(bit, tmp, to) \
VPSRLW bit, Y10, tmp \
VPAND Y12, tmp, to \ // to2 = 0x000<bit>000<bit>...
VPSUBW to, Y13, to // to2 = 0xFFFF.. or 0x0000 depending on bit
#define mulBit(bit) \
VPSLLQ $1, Y0, Y1 \
VPALIGNR $8, Y1, Y0, Y2 \
VPSRLQ $63, Y2, Y2 \
VPXOR Y1, Y2, Y2 \
VPAND Y1, Y14, Y3 \
VPUNPCKHQDQ Y3, Y3, Y3 \
VPXOR Y2, Y3, Y3 \
mask(bit, Y11, Y2) \
VPXOR Y3, Y8, Y3 \
VPAND Y3, Y2, Y4 \
VPXOR Y4, Y0, Y8 \
VMOVDQU Y3, Y0
// func mulByteRightx2(c00c10, c01c11 *[4]uint64, b byte)
TEXT ·mulByteRightx2(SB),NOSPLIT,$0
MOVQ c00c10+0(FP), AX
VMOVDQU (AX), Y0
MOVQ c01c11+8(FP), BX
VMOVDQU (BX), Y8
VPXOR Y13, Y13, Y13 // Y13 = 0x0000...
VPCMPEQB Y14, Y14, Y14 // Y14 = 0xFFFF...
VPSUBQ Y14, Y13, Y10
VPSUBW Y14, Y13, Y12 // Y12 = 0x00010001... (packed words of 1)
VPSLLQ $63, Y10, Y14 // Y14 = 0x10000000... (packed quad-words with HSB set)
VPBROADCASTB b+16(FP), X10 // X10 = packed bytes of b.
VPMOVZXBW X10, Y10 // Extend with zeroes to packed words.
mulBit($7)
mulBit($6)
mulBit($5)
mulBit($4)
mulBit($3)
mulBit($2)
mulBit($1)
mulBit($0)
VMOVDQU Y8, (BX)
VMOVDQU Y0, (AX)
RET
// func mulBitRightx2(c00c10, c01c11 *[4]uint64, e *[2]uint64)
TEXT ·mulBitRightx2(SB),NOSPLIT,$0
MOVQ c00c10+0(FP), AX
VMOVDQU (AX), Y0
MOVQ c01c11+8(FP), BX
VMOVDQU (BX), Y8
VPSLLQ $1, Y0, Y1
VPALIGNR $8, Y1, Y0, Y2
VPSRLQ $63, Y2, Y2
VPXOR Y1, Y2, Y2
VPSRLQ $63, Y1, Y3
VPSLLQ $63, Y3, Y3
VPUNPCKHQDQ Y3, Y3, Y3
VPXOR Y2, Y3, Y3
MOVQ e+16(FP), CX
VBROADCASTI128 (CX), Y2
VPXOR Y3, Y8, Y3
VPAND Y3, Y2, Y4
VPXOR Y4, Y0, Y8
VMOVDQU Y8, (BX)
VMOVDQU Y3, (AX)
RET