Notes: The EIP-2330 specifies the cost of EXTSLOAD as G[EXTCODE] + G[SLOAD]. A core dev in Eth E&D suggested that G[EXTCODEHASH] + G[SLOAD] would be a better cost. Issues with this pricing Assumptions: EIP-2330 is implemented Someone inherits an abstract contract like this in their DeFiProtocol:

Using lossy compression on uint256 to improve gas costs, ideally by a factor upto 4x. Abstract This document specifies compression of uint256 to smaller data structures like uint64, uint96, uint128, for optimising costs due to storage for Ethereum Smart Contracts. The smaller data structures are divided into two parts, in the first one we store significant bits and in the other number of left shifts needed on the significant bits to decompress. This document also includes two specifications for decompression due to the nature of compression being lossy, i.e. it causes underflow. Motivation Storage is costly, each storage slot costs almost $0.8 to initialize and $0.2 to update (20 gwei, 2000 ETHUSD). Usually we store money amounts in uint256 which takes up one entire slot. If it's DAI value, the range we work with mostly is 0.001 DAI to 1T DAI (or 10^12^). If it's ETH value, the range we work with mostly is 0.000001 ETH to 1B ETH. Similarly any token of any scale has a resonable range of 10^15^ amounts that we care / work with.

The following strategies are reviewed: Charm Finance Visor Finance Visor Finance GitHub Org: https://github.com/VisorFinance Smart Contracts Repo: private

This is a report for Solidity code review of following projects: Ampleforth Basis Cash Empty Set Dollars Ampleforth Smart contracts GitHub repo: ampleforth/uFragments. TechStack: Truffle V4, OpenZeppelin V2.