Copy
64assembly {
65    // Load free memory pointer
66    let memPtr := mload(64)
67
68    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
69    mstore(
70        memPtr,
71        0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9
72    )
73    mstore(add(memPtr, 32), _owner)
74    mstore(add(memPtr, 64), _spender)
75    mstore(add(memPtr, 96), _amount)
76    mstore(add(memPtr, 128), nonce)
77    mstore(add(memPtr, 160), _deadline)
78
79    hashStruct := keccak256(memPtr, 192)
80}
81
82bytes32 eip712DomainHash = _domainSeparator();
83
84// Assembly for more efficient computing:
85// bytes32 hash = keccak256(
86//     abi.encodePacked(uint16(0x1901), eip712DomainHash, hashStruct)
87// );
88
89bytes32 hash;
90
91assembly {
92    // Load free memory pointer
93    let memPtr := mload(64)
94
95    mstore(
96        memPtr,
97        0x1901000000000000000000000000000000000000000000000000000000000000
98    ) // EIP191 header
99    mstore(add(memPtr, 2), eip712DomainHash) // EIP712 domain hash
100    mstore(add(memPtr, 34), hashStruct) // Hash of struct
101
102    hash := keccak256(memPtr, 66)
103}