Badger Citadel contest - 0xNazgul's results

In require(), Use != 0 Instead of > 0 With Uint Values

Context: Funding.sol#L163-L191, Funding.sol#L315-L330, Funding.sol#L334-L344, Funding.sol#L414-L441, Funding.sol#L447-L468, KnightingRound.sol#L109-L149 (For L124 and L128), KnightingRound.sol#L162-L204, KnightingRound.sol#L209-L223, KnightingRound.sol#L308-L321, KnightingRound.sol#L327-L339, KnightingRound.sol#L402-L415, StakedCitadelVester.sol#L132-L152, SupplySchedule.sol#L55-L65, SupplySchedule.sol#L84-L126, SupplySchedule.sol#L178-L233

Description: In a require, when checking a uint, using != 0 instead of > 0 saves 6 gas. This will jump over or avoid an extra ISZERO opcode.

Recommendation: Use != 0 instead of > 0 with uint values but only in require() statements.

Catching The Array Length Prior To Loop

Context: GlobalAccessControlManaged.sol#L46-L57

Description: One can save gas by caching the array length (in stack) and using that set variable in the loop. Replace state variable reads and writes within loops with local variable reads and writes. This is done by assigning state variable values to new local variables, reading and/or writing the local variables in a loop, then after the loop assigning any changed local variables to their equivalent state variables.

Recommendation: Simply do something like so before the for loop: uint length = variable.length. Then add length in place of variable.length in the for loop.

Function Ordering via Method ID

Context: All Contracts

Description: Contracts most called functions could simply save gas by function ordering via Method ID. Calling a function at runtime will be cheaper if the function is positioned earlier in the order (has a relatively lower Method ID) because 22 gas are added to the cost of a function for every position that came before it. The caller can save on gas if you prioritize most called functions. One could use This tool to help find alternative function names with lower Method IDs while keeping the original name intact.

Recommendation: Find a lower method ID name for the most called functions for example mostCalled() vs. mostCalled_41q() is cheaper by 44 gas.

Use ++index instead of index++ to increment a loop counter

Context: CitadelMinter.sol#L143-L159, SupplySchedule.sol#L178-L233, GlobalAccessControlManaged.sol#L46-L57

Description: Due to reduced stack operations, using ++index saves 5 gas per iteration.

Recommendation: Use ++index to increment a loop counter.

In if(), Use > 0 Instead of !=0 With Uint Values

Context: StakedCitadel.sol#L396-L429, StakedCitadel.sol#L764-L777, StakedCitadel.sol#L808-L824, StakedCitadel.sol#L898-L933 (For L921 and L925, StakedCitadelVester.sol#L85-L97

Description: In a require, when checking a uint, using != 0 instead of > 0 saves 6 gas. This will jump over or avoid an extra ISZERO opcode. But this only works in require() and not in other situations hence it is cheaper to use > 0 instead of !=0 with uint values in an if().

Recommendation: Use != 0 instead of > 0 with uint values but only in require() statements and use > 0 instead of != 0 in other situations.