Frank Denis 5af89b3dcc
std.crypto.chacha: support larger vectors on AVX2 and AVX512 targets (#15809)
* std.crypto.chacha: support larger vectors on AVX2 and AVX512 targets

Ryzen 7 7700, ChaCha20/8 stream, long outputs:

Generic: 3268 MiB/s
AVX2   : 6023 MiB/s
AVX512 : 8086 MiB/s

Bump the rand.chacha buffer a tiny bit to take advantage of this.
More than 8 blocks doesn't seem to make any measurable difference.

ChaChaPoly also gets a small performance boost from this, albeit
Poly1305 remains the bottleneck.

Generic:  707 MiB/s
AVX2   :  981 MiB/s
AVX512 : 1202 MiB/s

aarch64 appears to generally benefit from 4-way vectorization.

Verified on Apple Silicon, but also on a Cortex A72.
2023-05-22 20:33:35 +02:00
..
2022-05-24 22:48:51 -04:00
2022-12-18 01:46:09 -05:00
2023-04-21 16:36:10 -04:00