Why using `!=X` instead of `> X` is cheaper in solidity
Comparison operator requires the EVM to perform a subtraction between the two values
- When a comparison operator is used on uint256 values, it requires the EVM to perform a subtraction operation between the two values, which takes up more gas than a simple check for equality.
- When we use
!=X
for comparison, the EVM checks if the value is non-zero by simply checking the zero flag, which is more efficient in terms of gas cost compared to checking for a positive value using> X
. This is because checking for a positive value requires the EVM to perform a subtraction operation to determine whether the value is positive or not.
Therefore, in Solidity, it is more gas-efficient to use !=X
instead of > X
when comparing unsigned integer values.