what is the use of cn_slow_hash_prehashed here?

[calidion]

by searching cn_slow_hash_prehashed to know that it is only a definition.

eric@eric-laptop:~/Monero/monero$ grep cn_slow_hash_prehashed . -Rn
./src/crypto/hash.h:78:  inline void cn_slow_hash_prehashed(const void *data, std::size_t length, hash &hash, int variant = 0) {

[moneromooo-monero]

Is there a bug here ?

[calidion]

@moneromooo-monero

I am determining which function is compatible with the old cryptonight algorithm.
it seems cn_slow_hash doesn't compatible with the old cryptonight algorithm.

I have changed my code base from the original cryptonote to monero.
and tested cn_slow_hash with the following (variant, prehashed) pair:

0, 0,
0, 1,
1, 0,
1, 1

none of them worked for the old network.

[moneromooo-monero]

Ignore prehashed, always set it to 0. variant 0 is the original CN. 1 is what monero is using now. 2 is what monero will be using from v8.

See #4218

[calidion]

@moneromooo-monero

Thanks.

I set the last two parameter to 0, 0 for cn_slow_hash,
but it still not work with the old network.

you can checkout code from https://github.com/vigcoin/coin

where master can not update while old branch can.

the only difference is the cn_slow_hash.

[calidion]

@moneromooo-monero

by make clean and make again.
the new compiled works with the old network now.

Thank you very much.

[moneromooo-monero]

+invalid