RE: [PATCH 0/1] Add KUnit tests for lib/crc16.c
From: David Laight
Date: Thu Sep 26 2024 - 12:22:17 EST
...
> The checksums for the randomly-generated test cases were calculated
> using a reference implementation [1] and this test compares them against
> the values yielded by the kernel's implementation.
I'd just use a naïve implementation - doesn't really matter
if it is a bit slow.
Slow is relative - this code only takes 35ms to crc-64 over 5MB of data.
{
volatile const uint32_t *r = (const void *)buf;
for (crc = 0; r < (const uint32_t *)buf_end; r++) {
uint64_t val = le32toh(*r);
crc ^= bswap64(val);
for (i = 0; i < 32; i++) {
if (crc & (1ull << 63))
crc = (crc << 1) ^ 0x42f0e1eba9ea3693ull;
else
crc = crc << 1;
}
}
}
David
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