int8, int128, int256

The storage of int8, int128, int256 in memory are very simple, they are written directly at our chosen memory location and are returned the same. Yul wraps around negative int[n] values.

// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.0;

contract Yul {
    function int8InMemory(int8 value) public pure returns (bytes32) {
        assembly {
            mstore(0x80, value)
            return(0x80, 0x20)
        }
    }

    function int128InMemory(int128 value) public pure returns (bytes32) {
        assembly {
            mstore(0x80, value)
            return(0x80, 0x20)
        }
    }

    function int256InMemory(int256 value) public pure returns (bytes32) {
        assembly {
            mstore(0x80, value)
            return(0x80, 0x20)
        }
    }
}

🚨 Due to the tricky nature of the storage of int[n] types, apply more care when storing and manipulating values from storage.

🚨 Do not store negative int[n] values directly from your Yul block of code, Yul treats it as a uint[n] type overflow, meaning that -1 will be converted to (2^256) - 1. This can lead to security breaches. Yul wraps around negative int[n] values.