Using newer compiler versions and the optimizer gives gas optimizations
and additional safety checks for free!
The advantages of versions 0.8.* over <0.8.0 are:
Safemath by default from 0.8.0 (can be more gas efficient than
library based safemath.)
Low level
inliner
from 0.8.2, leads to cheaper runtime gas. Especially relevant when
the contract has small functions. For example, OpenZeppelin
libraries typically have a lot of small helper functions and if they
are not inlined, they cost an additional 20 to 40 gas because of 2
extra jump instructions and additional stack operations needed for
function calls.
Optimizer improvements in packed
structs:
Before 0.8.3, storing packed structs, in some cases used an
additional storage read operation. After
EIP-2929, if the slot was
already cold, this means unnecessary stack operations and extra
deploy time costs. However, if the slot was already warm, this means
additional cost of 100 gas alongside the same unnecessary stack
operations and extra deploy time costs.
Custom
errors from
0.8.4, leads to cheaper deploy time cost and run time cost. Note:
the run time cost is only relevant when the revert condition is met.
In short, replace revert strings by custom errors.
Handle
hrkrshnn
Vulnerability details
Upgrade to at least 0.8.4
Using newer compiler versions and the optimizer gives gas optimizations and additional safety checks for free!
The advantages of versions
0.8.*
over<0.8.0
are:0.8.0
(can be more gas efficient than library based safemath.)0.8.2
, leads to cheaper runtime gas. Especially relevant when the contract has small functions. For example, OpenZeppelin libraries typically have a lot of small helper functions and if they are not inlined, they cost an additional 20 to 40 gas because of 2 extrajump
instructions and additional stack operations needed for function calls.0.8.3
, storing packed structs, in some cases used an additional storage read operation. After EIP-2929, if the slot was already cold, this means unnecessary stack operations and extra deploy time costs. However, if the slot was already warm, this means additional cost of100
gas alongside the same unnecessary stack operations and extra deploy time costs.0.8.4
, leads to cheaper deploy time cost and run time cost. Note: the run time cost is only relevant when the revert condition is met. In short, replace revert strings by custom errors.