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[0/3] libcpp: improve x86 vectorized helpers

Message ID df196bee-cbf8-0221-f412-235d8f79a1d5@ispras.ru
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Series libcpp: improve x86 vectorized helpers | expand

Message

Alexander Monakov Aug. 6, 2024, 4:17 p.m. UTC 
Hello!

As discussed, I'm sending patches that reimplement our SSE4.2 search_line_fast
helper with SSSE3, and then add the corresponding AVX2 helper. They are on top
of Andi's "Remove MMX code path in lexer" patch, which was approved, but not
committed yet (Andi, can you push your own patch?).

Apparently the branch where we find a possible EOL and return from the function
is poorly predictable, hence a small win from AVX2 use (wider vectors => fewer
mispredicts).

I'm also attaching here a microbenchmark for testing all variants in isolation.

Alexander

Comments

Andi Kleen Aug. 6, 2024, 6:42 p.m. UTC | #1 
> Andi, can you push your own patch?).

Done.

-Andi