Open code423n4 opened 2 years ago
I did some gas golfing to figure out if ++i
is really less gas consuming than i++
. We would only save 5 gas per iteration but also lose in code clarity, so this gas saving trade off isn't really worth it.
About the unchecked part, results are a bit more convincing but still negligible. We would save 77 gas per iteration but as stated in the following issue, it is not possible to write unchecked { ++i }
inline so we would have to write a helper function which would make our code less legible and harder to maintain in the future.
I've acknowledged the issue but we won't actually make the changes cause we prefer to keep a simple code base that will be easier to maintain in the future.
Handle
robee
Vulnerability details
Prefix increments are cheaper than postfix increments. Further more, using unchecked {++x} is even more gas efficient, and the gas saving accumulates every iteration and can make a real change There is no risk of overflow caused by increamenting the iteration index in for loops (the
++i
infor (uint256 i = 0; i < numIterations; ++i)
). But increments perform overflow checks that are not necessary in this case. These functions use not using prefix increments (++x
) or not using the unchecked keyword: