实验性项目，通过比特切片等技术来实现sm4，验证性能。
目前性能如下：
64组：
goos: windows
goarch: amd64
pkg: github.com/emmansun/sm4bs
cpu: Intel(R) Core(TM) i5-9500 CPU @ 3.00GHz
BenchmarkXorRK64-6 38663529 29.36 ns/op 0 B/op 0 allocs/op
BenchmarkSbox64-6 67601062 17.83 ns/op 0 B/op 0 allocs/op
BenchmarkTao64-6 14010654 82.90 ns/op 0 B/op 0 allocs/op
BenchmarkL64-6 54585649 22.99 ns/op 0 B/op 0 allocs/op
BenchmarkBS64TransposeAvx-6 4376485 274.2 ns/op 0 B/op 0 allocs/op
BenchmarkBS64TransposeRevAvx-6 4492495 267.5 ns/op 0 B/op 0 allocs/op
BenchmarkEncrypt64Blocks-6 298386 4686 ns/op 218.54 MB/s 1536 B/op 2 allocs/op
128组：
goos: windows
goarch: amd64
pkg: github.com/emmansun/sm4bs
cpu: Intel(R) Core(TM) i5-9500 CPU @ 3.00GHz
BenchmarkXor32-6 84093679 13.37 ns/op
BenchmarkXorRK-6 37912296 31.48 ns/op
BenchmarkL128-6 52159624 22.68 ns/op 0 B/op 0 allocs/op
BenchmarkSbox128-6 68027982 17.27 ns/op 0 B/op 0 allocs/op
BenchmarkTao128-6 14089119 86.37 ns/op 0 B/op 0 allocs/op
BenchmarkBS128TransposeAvx-6 2279635 511.7 ns/op 0 B/op 0 allocs/op
BenchmarkBS128TransposeRevAvx-6 2365981 511.2 ns/op 0 B/op 0 allocs/op
BenchmarkEncrypt128Blocks-6 205614 5557 ns/op 368.55 MB/s 3072 B/op 2 allocs/op
256组：
goos: windows
goarch: amd64
pkg: github.com/emmansun/sm4bs
cpu: Intel(R) Core(TM) i5-9500 CPU @ 3.00GHz
BenchmarkSbox256-6 68508790 17.99 ns/op 0 B/op 0 allocs/op
BenchmarkTao256-6 13837366 88.67 ns/op 0 B/op 0 allocs/op
BenchmarkL256-6 50736309 22.45 ns/op 0 B/op 0 allocs/op
BenchmarkXorRK256-6 35646387 34.23 ns/op 0 B/op 0 allocs/op
BenchmarkXor32x256-6 54216703 21.92 ns/op 0 B/op 0 allocs/op
BenchmarkBS256TransposeAvx-6 1000000 1046 ns/op 0 B/op 0 allocs/op
BenchmarkBS256TransposeRevAvx-6 1000000 1020 ns/op 0 B/op 0 allocs/op
BenchmarkEncrypt256Blocks-6 167295 6869 ns/op 596.28 MB/s 6144 B/op 2 allocs/op
AES-NI + AVX2方案：
goos: windows
goarch: amd64
cpu: Intel(R) Core(TM) i5-9500 CPU @ 3.00GHz
BenchmarkAESNIEncrypt64Blocks-6 613549 2019 ns/op 507.24 MB/s 0 B/op 0 allocs/op
BenchmarkAESNIEncrypt64Blocks-6 293706 3952 ns/op 518.16 MB/s 0 B/op 0 allocs/op
BenchmarkAESNIEncrypt64Blocks-6 149754 7921 ns/op 517.10 MB/s 0 B/op 0 allocs/op
Detail：
- 128/256组：#1
Reference: