The unused function definitions are hidden behind a
`#ifndef ZSTD_NO_UNUSED_FUNCTIONS` check.
Initially hiding all functions which are unused and take up more than
2KB of stack space, because these will show up as warnings in the
Linux Kernel build system.
new version easier to vectorize
leads to smaller code and faster execution
notably at the last recombination stage
(basically, fixed cost per block).
Assembly inspected with godbolt
On my laptop, with `clang` and `-mavx2` :
2K block : 1280 MB/s -> 1550 MB/s
8K block : 1750 MB/s -> 1860 MB/s
* All copyright lines now have -2020 instead of -present
* All copyright lines include "Facebook, Inc"
* All licenses are now standardized
The copyright in `threading.{h,c}` is not changed because it comes from
zstdmt.
The copyright and license of `divsufsort.{h,c}` is not changed.
changed workspace parameter convention
to always provide workspaceSize,
so that size can be explicitly checked.
Also, use more enum to make the meaning of some parameters more explicit.
