[Mesa-dev] [PATCH] util: import sha1 implementation from OpenBSD

[Vladislav Egorov]

14.01.2017 01:45, Timothy Arceri пишет:
> I'm asking for a chance to test before we jump in, its probably not a
> big deal and I may even still be able to reduce my use of hashing but
> it would be nice to be given a few days to test and even explore
> alternatives before jumping on this implementation.
A very quick and very dirty simple benchmark. I took shader-cache from 
github, branch shader-cache39. Then I've applied my preprocessor patch 
on top (because shader-cache still uses preprocessor even if the shader 
is cached and it was painful to see preprocessor taking more than half 
of the whole time). Then I've compiled it with openssl and with the 
Emil's patch. Full run on shader-db (300Mb+ of shaders) with 
shader-cache warmed up. It takes 78s, spends in libcrypto 0.27%. With 
OpenBSD SHA1 it runs approximately the same time, spends 0.53% in 
SHA1Transform() and other SHA1* functions. Subtest - 46Mb of shaders 
from Total War: Attila - 3.10s (for some reason, the cache works much 
faster on smaller subsets than on full shader-db). 1.08% were spent in 
libcrypto, 1.04% in sha1_block_data_order_avx2(). With OpenBSD 3.07s - 
2.27% in SHA1Transform() and other SHA1* functions.

Overall not that significant in context of shader-cache, but as 
expected, on Haswell it's twice slower than OpenSSL's AVX2 implementation.