* xorIn and copyOut function pointers cause input and output data
to be moved to heap. This degrades performance of calling code.
* This change removes usage of those function pointers. We will always
use unaligned implementation as it's faster (but may crash on some
systems)
* Benchmark compares generic vs unaligned xorIn and copyOut
benchmark old ns/op new ns/op delta
BenchmarkPermutationFunction-4 463 815 +76.03%
BenchmarkShake128_MTU-4 4443 8180 +84.11%
BenchmarkShake256_MTU-4 4739 9060 +91.18%
BenchmarkShake256_16x-4 71886 132629 +84.50%
BenchmarkShake256_1MiB-4 3695138 6649012 +79.94%
BenchmarkCShake128_448_16x-4 21210 24611 +16.03%
BenchmarkCShake128_1MiB-4 3009342 3396496 +12.87%
BenchmarkCShake256_448_16x-4 26034 27785 +6.73%
BenchmarkCShake256_1MiB-4 3654713 3829404 +4.78%