hash: implement fast crc32c #24279
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hash: implement fast crc32c #24279
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alexrp
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Jun 27, 2025
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Implements an accelerated version of CRC-32C using the Intel SSE4.2 instruction. I'm not sure if anyone actually.. uses CRC-32C with Zig, but nevertheless it's a nice improvement. I've also spent a bit of time trying to describe how the algorithm implemented here works, although the math behind how combing CRC blocks is quite complex, so it doesn't go into too much detail.
I've fuzzed the algorithm for a bit with different sized inputs as well as making sure it produces the same result as the generic implementation.
You can find the benchmark here, https://gist.github.com/Rexicon226/e91d750f5842af43d96b2f0a526ba392