optimize CRC-8 checksum with lookup table #3028
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KRRT7
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It would be good to optimize this routine, but there's no need to store the LUT. It makes more sense to generate them at startup, as we do for the other CRC algorithms.
I would merge a version of this that adds CRC8BODY to crc.py with poly 0xD5. See the CRC8J1850 example in the Chrysler car port.
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can also use a @cache instead of globals to cache the generation if you go this route |
Generate CRC-8 table with polynomial 0xD5 at import time, following the existing pattern for other CRC tables.
Replace hardcoded 256-entry lookup table with import from shared crc module, following reviewer feedback.
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went with the CRC8J1850 example |
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@sshane @jyoung8607 are you guys interested in performance optimizations for opendbc? |
Yes, but they need to be visible changes that someone will notice, not micro-optimizations. Making tests faster is a good place to start, e.g. #3024. |
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sounds good, I'll see what I can come up with. |
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No car changes detected |
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Replace bit-by-bit CRC-8 calculation with precomputed lookup table for improved performance.