On 02/24/2014 04:41 AM, Jan Beulich wrote:
So I'm guessing this hash is deliberately using the CRC32 instruction
"backwards", which would actually make sense: an actual CRC is actually
a pretty poor hash due to linearity.
OK, it really is even more confusing than that.
It does seem like the crc32 instruction really *is* commutative, which
isn't something I would personally have expected at all.
Given that fact, I suspect the ordering in the DPDK is actually a bug,
and that we should correct the ordering (which I would do at the call
sites because it seems to make the code clearer) because it reduces the
size of the loop by two instructions.
I guess I should find out how to file a bug report against DPDK too...
-hpa
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