EffiProxy

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Overview

EffiProxy is a EIP-1967 standard gas optimization implementation.

Background

In the realm of upgradable contracts, especially for contract wallets, the gas efficiency of a contract plays a pivotal role in user experience. Notable examples include Safe-global::SafeProxy.sol and SoulWallet::SoulWalletProxy.sol.

Key Features

• ✨Gas Efficiency: Compared to Yul versions, EffiProxy reduces deployment cost by over 13k gas, achieving a 15% reduction.

  Note: Writing code that is hard to read is generally not a good practice. However, for contracts like proxy, which have fixed logic and are inherently minimalistic in code, it is indeed possible to improve gas efficiency by writing low-level code without adversely affecting any other components.

  The opcode for EffiProxy is as follows: 60518060225f395f73111111111111111111111111111111111111111160165155f373ffffffffffffffffffffffffffffffffffffffff7f360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc5416365f5f375f5f365f845af43d5f5f3e604d573d5ffd5b3d5ff3

  For an explanation of the above opcode, please see EffiProxy_v2.asm.

  Note: 1111111111111111111111111111111111111111 in the code is a constructor parameter. You will need to replace it with your own specified logic contract address when using it.

  The functionality of the above opcode is equivalent to the following Solidity code:

  pragma solidity ^0.8.20;
  contract YulProxy {
      bytes32 private constant _IMPLEMENTATION_SLOT =
          0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
  
      constructor(address logic) {
          assembly ("memory-safe") {
              sstore(_IMPLEMENTATION_SLOT, logic)
          }
      }
  
      fallback() external payable {
          assembly {
              calldatacopy(0, 0, calldatasize())
              let _singleton := and(
                  sload(_IMPLEMENTATION_SLOT),
                  0xffffffffffffffffffffffffffffffffffffffff
              )
              let success := delegatecall(
                  gas(),
                  _singleton,
                  0,
                  calldatasize(),
                  0,
                  0
              )
              returndatacopy(0, 0, returndatasize())
              if iszero(success) {
                  revert(0, returndatasize())
              }
              return(0, returndatasize())
          }
      }
  }
  

GAS

• Test

forge test -vv | grep 'deploy'

• Test result:

Name	GAS
Yul version [code]	83754 gas
asm version [code]	70570 gas

We can see that the Asm version reduces gas by more than 15% at deployment time compared to the Yul version.

note: Compared to the Yul version, the Asm version also reduces gas cost during call, but the reduction is very slight (-20 gas per call), so we will not list it here.

Usage

Reference: gasHelper_asm.sol

Note

The Asm is written with the PUSH0 opcode, so it can only be deployed with EVM version >= Shanghai.