xorsimd

README

XOR SIMD

Introduction:

• XOR code engine in pure Go.

• High Performance: More than 270GB/s per physics core.

Performance

Performance depends mainly on:

• CPU instruction extension.

• Number of source row vectors.

Platform:

AWS c5d.xlarge (Intel(R) Xeon(R) Platinum 8124M CPU @ 3.00GHz)

All test run on a single Core.

I/O = (src_num + 1) * vector_size / cost

Src Num	Vector size	AVX512 I/O (MB/S)	AVX2 I/O (MB/S)	SSE2 I/O (MB/S)
5	4KB	270403.73	142825.25	74443.91
5	1MB	26948.34	26887.37	26950.65
5	8MB	17881.32	17212.56	16402.97
10	4KB	190445.30	102953.59	53244.04
10	1MB	26424.44	26618.65	26094.39
10	8MB	15471.31	14866.72	13565.80

Documentation

Index

• Variables
• func Encode(dst []byte, src [][]byte) (n int)
• func EncodeBytes(dst, a, b []byte) int
• func EncodeDW(dst, a, b []byte)
• func EncodeW(dst, a, b []byte)

Variables

var EnableAVX512 = true

EnableAVX512 may slow down CPU Clock (maybe not). TODO need more research: https://lemire.me/blog/2018/04/19/by-how-much-does-avx-512-slow-down-your-cpu-a-first-experiment/

Functions

func Encode

func Encode(dst []byte, src [][]byte) (n int)

Encode encodes elements from source slice into a destination slice. The source and destination may overlap. Encode returns the number of elements encoded, which will be the minimum of len(src[i]) and len(dst).

func EncodeBytes

func EncodeBytes(dst, a, b []byte) int

EncodeBytes encodes the bytes in a and b into a destination slice. The source and destination may overlap. EncodeBytes returns the number of elements encoded, which will be the minimum of len(dst), len(a), len(b).

func EncodeDW

func EncodeDW(dst, a, b []byte)

EncodeDW XORs of packed doubleword (16 Bytes). The slice arguments a, b, dst's lengths are assumed to be at least 16, if not, it will panic.

This functions could be used for AES encryption, AES block size is 16 bytes in Go.

func EncodeW

func EncodeW(dst, a, b []byte)

EncodeW XORs of word (8 Bytes). The slice arguments a, b, dst's lengths are assumed to be at least 8, if not, will panic.