feat: FHEVM mulDiv

[matteoettam09]

Any idea on how to implement mulDiv

with this API:

mulDiv(euintXX x, uint256 y, uint256 denominator) → euintXX result

Assuming it's possible.

[arr00]

Zama doesn't support operations using uint256 (details here). What could be done is mulDiv by plaintext uint64 or even uint128 values.

[matteoettam09]

I guess 128 could still do the trick,

https://github.com/OrionFinanceAI/protocol/blob/bcdd73586bac2ab2b13ab5c1c387f83a6fdd44f6/contracts/orchestrators/InternalStatesOrchestrator.sol#L487

This one without mulDiv has led me to move from euint32 to euint128, which increased the costs just to avoid overflow here. Would be great to have a mulDiv(euin128, uint128, uint128)

[arr00]

Will consider adding it to the library. Thanks for the request.

[matteoettam09]

Hi @arr00 do you think you have bandwith to implement this?

Currently a blocker from my side:

https://github.com/OrionFinanceAI/protocol/blob/b3f488a8a3fa1bc62fa17b6a8c57e737a670c0a5/contracts/orchestrators/InternalStatesOrchestrator.sol#L490

Thank you