Why Precompiles?
Learn about why you should utilize Precompiles in your smart contracts.
Adding precompiles to the EVM offers several significant advantages, which we will outline in this chapter.
Performance Optimization
Precompiles primarily optimize the performance of specific computations. Introducing a new precompile can greatly reduce the computational resources required for certain tasks, thereby enhancing the performance of smart contracts and decentralized applications (DApps) that rely on these tasks.
For instance, the SHA256 hash function (0x02) and the RIPEMD160 hash function (0x03) serve as examples of precompiles that significantly boost performance. Implementing these functions within a smart contract would be computationally expensive and slow, whereas as precompiles, they execute quickly and efficiently.
Security
Incorporating a function as a precompile allows developers to leverage libraries that have been thoroughly reviewed and audited, thus reducing the risk of bugs and vulnerabilities, which enhances overall security.
For example, the ModExp (0x05) precompile safely performs modular exponentiation, a complex mathematical operation utilized in various cryptographic functions.
Access to Go Libraries
Precompiles are implemented in Go, allowing access to the rich ecosystem of existing Go libraries. This access eliminates the need for reimplementation, which can be labor-intensive and carries the risk of introducing bugs during the translation from Go to Solidity.
Consider the implementation of the SHA256 hash algorithm to understand the complexity involved in reimplementing it in Solidity.
Gas Efficiency
Introducing a new precompile to the EVM can enhance gas efficiency for specific computations, thereby lowering execution costs. This makes it feasible to incorporate more complex operations into smart contracts, expanding their functionality without significantly increasing transaction costs.
The identity precompile (0x04), which copies and returns input data, exemplifies this. Though simple, it provides gas efficiency by being faster and cheaper than implementing the same functionality in a standard contract.
Advanced Features and Functionality
By adding new precompiles to the EVM, developers can introduce advanced features and functionalities, such as complex mathematical calculations, advanced cryptographic operations, and new data structures. This can unlock new possibilities for DApps and smart contracts, enabling them to execute tasks that would otherwise be too computationally demanding or technically challenging.
Precompiles for elliptic curve operations, such as ecadd (0x06), ecmul (0x07), and ecpairing (0x08), enable advanced cryptographic functionality within EVM smart contracts. These precompiles are crucial for implementing zk-SNARKs, a form of zero-knowledge proof, in Ethereum.
Interoperability
Certain precompiles can enhance the interoperability of the EVM with other blockchains or systems. For instance, precompiles can be utilized to verify proofs from other chains or perform operations compatible with different cryptographic standards.
The BLS12-381 elliptic curve operations precompiles (0x0a through 0x13, added in the Istanbul upgrade) improve EVM interoperability by allowing operations that are compatible with the BLS signature scheme, potentially facilitating inter-blockchain communication.
