The optimizer dilemma: unpacks Ethereum’s optimization mechanisms
In this article, we will deepen the world of Ethereum optimizer and explore why ‘the address (this). The balance is not always optimized for ‘balance ().
Background on solidity compilers
Ethereum’s solidity compiler is a critical component that translates the high -level code written in solidity (the programming language used to build decentralized applications) into low -level bytecode. This process implies a series of optimization steps aimed at improving the performance, readability and maintenance of the code.
The optimizer: a key component
Ethereum Virtual Machine (EVM) has an optimizer that runs at the top of the solidity compiler. Its main function is to reduce the size and complexity of the bytecode produced by the compiler while mainly or even increase the precision of the optimized code. The optimizer considers several factors, including:
- Gas cost : higher gas costs can lead to optimization decisions.
- Code length : The longest bases are more likely to be optimized for performance.
- Use of the set of instructions : The frequent use of complex instructions may need optimizations.
Why ‘address (this) .balance’ is not always optimized
Consider an example:
`SOLIDITY
Pragma solidity ^0.8.0;
Mycontract contract {
Function Balance () Public View Returns (Uint256) {
RETURN ADDRESS (this) .BALANCE;
}
// We introduce a simple optimization: when called self.balance (),
// We update the balance without usingaddress (this) .balance.
UPDATEBALANCE FUNCTION () PUBL {
Uint256 Newbalance = Self.balance ();
address (this) .balance = 0; // This line can be optimized
}
}
In this case, the optimizer will probably choose to optimize theaddress (east) .balance = 0when calling self.balance (). This is because updating a local variable without using its original value can reduce the use of gas.
The self.balance () vs. Address (this) .BALANCE () DIFFERENCE
While he may like self.balance () and address (this) .balance () They are equivalent, there is an important distinction:
Self.balance ()Returns the balance of the instance of the current contract.
Address (this) .BALANCE ()Returns the balance of the current contract.
This means that by calling updatebalance (), we want to update the local variable in the current instance of the contract (self) instead of modifying the global state. By usingaddress (this) .balance (), we ensure that optimization is applied correctly, since it refers to the local value instead of the global.
Conclusion
In conclusion, although the solidity compiler and its optimizer strive to optimize the code for performance, there are scenarios in which optimizations do not always apply or can ignore intentionally. The key conclusion of this example is that the difference between self.balance ()andaddress (east) .balance () It is found in its reference semantics, which can affect optimization decisions.
As developers who work with EVM of Ethereum, understanding these subtleties will help you write a more efficient, legible and maintainable code while minimizing the use of gas.