RequireVsCustomError.md

RequireVsCustomError_r.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4; // optimize 200

/**
 * @title RequireVsCustomError
 * @author IllIllI
 */
contract RequireVsCustomError {
    function test() public view {
        require(uint256(uint160(msg.sender)) > block.number, "Err");
    }
    function ignore() external pure {
        revert Err();
    }
    error Err();
}

RequireVsCustomError_c.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4; // optimize 200

/**
 * @title RequireVsCustomError
 * @author IllIllI
 */
contract RequireVsCustomError {
    function test() public view {
        if (uint256(uint160(msg.sender)) >= block.number) { revert Err(); }
    }
    function ignore() external pure {
        revert Err();
    }
    error Err();
}

Diff

diff --git a/RequireVsCustomError_r.sol b/RequireVsCustomError_c.sol
index 169d1d1..abf3a64 100644
--- a/RequireVsCustomError_r.sol
+++ b/RequireVsCustomError_c.sol
@@ -7,7 +7,7 @@ pragma solidity ^0.8.4; // optimize 200
  */
 contract RequireVsCustomError {
     function test() public view {
-        require(uint256(uint160(msg.sender)) > block.number, "Err");
+        if (uint256(uint160(msg.sender)) >= block.number) { revert Err(); }
     }
     function ignore() external pure {
         revert Err();

Compiled binary

$ solc RequireVsCustomError_r.sol --bin --optimize --optimize-runs 200 | egrep "^60[0-9]+"
608060405234801561001057600080fd5b5060ce8061001f6000396000f3fe6080604052348015600f57600080fd5b506004361060325760003560e01c8063ed6f8663146037578063f8a8fd6d14603f575b600080fd5b603d6045565b005b603d605e565b604051636327e1b960e11b815260040160405180910390fd5b43331160965760405162461bcd60e51b815260206004820152600360248201526222b93960e91b604482015260640160405180910390fd5b56fea2646970667358221220a2f3cf5bbd0c3c1806dba84640032c876a6b960c78f17f05c2197296dff4fb9a64736f6c63430008040033

$ solc RequireVsCustomError_c.sol --bin --optimize --optimize-runs 200 | egrep "^60[0-9]+"
608060405234801561001057600080fd5b5060b58061001f6000396000f3fe6080604052348015600f57600080fd5b506004361060325760003560e01c8063ed6f8663146037578063f8a8fd6d14603f575b600080fd5b603d6045565b005b603d605e565b604051636327e1b960e11b815260040160405180910390fd5b433310607d57604051636327e1b960e11b815260040160405180910390fd5b56fea26469706673582212209f434c6b7dd3b9c5a19edbc55b544e7832bdcb6f49110723cc881c0d9ca1d22b64736f6c63430008040033

Opcodes

PC.Req	Operation.Req	Gas.Req	PC.Cus	Operation.Cus	Gas.Cus
126(0x7e)	NUMBER(0x43)	2	126(0x7e)	NUMBER(0x43)	2
127(0x7f)	CALLER(0x33)	2	127(0x7f)	CALLER(0x33)	2
			128(0x80)	LT(0x10)	3
128(0x80)	GT(0x11)	3
129(0x81)	PUSH1(0x60) ["0x96"]	3	129(0x81)	PUSH1(0x60) ["0x7d"]	3
131(0x83)	JUMPI(0x57)	10	131(0x83)	JUMPI(0x57)	10
132(0x84)	PUSH1(0x60) ["0x40"]	3	132(0x84)	PUSH1(0x60) ["0x40"]	3
134(0x86)	MLOAD(0x51)	3	134(0x86)	MLOAD(0x51)	3
			135(0x87)	PUSH4(0x63) ["0x63","0x27",...	3
135(0x87)	PUSH3(0x62) ["0x46","0x1b",...	3
139(0x8b)	PUSH1(0x60) ["0xe5"]	3	140(0x8c)	PUSH1(0x60) ["0xe1"]	3
141(0x8d)	SHL(0x1b)	3	142(0x8e)	SHL(0x1b)	3
142(0x8e)	DUP2(0x81)	3	143(0x8f)	DUP2(0x81)	3
143(0x8f)	MSTORE(0x52)	3	144(0x90)	MSTORE(0x52)	3
144(0x90)	PUSH1(0x60) ["0x20"]	3	145(0x91)	PUSH1(0x60) ["0x04"]	3
146(0x92)	PUSH1(0x60) ["0x04"]	3
148(0x94)	DUP3(0x82)	3
149(0x95)	ADD(0x1)	3	147(0x93)	ADD(0x1)	3
150(0x96)	MSTORE(0x52)	3
151(0x97)	PUSH1(0x60) ["0x03"]	3	148(0x94)	PUSH1(0x60) ["0x40"]	3
153(0x99)	PUSH1(0x60) ["0x24"]	3
155(0x9b)	DUP3(0x82)	3
156(0x9c)	ADD(0x1)	3
157(0x9d)	MSTORE(0x52)	3
158(0x9e)	PUSH3(0x62) ["0x22","0xb9",...	3
162(0xa2)	PUSH1(0x60) ["0xe9"]	3
164(0xa4)	SHL(0x1b)	3
165(0xa5)	PUSH1(0x60) ["0x44"]	3
167(0xa7)	DUP3(0x82)	3
168(0xa8)	ADD(0x1)	3
169(0xa9)	MSTORE(0x52)	3
170(0xaa)	PUSH1(0x60) ["0x64"]	3
172(0xac)	ADD(0x1)	3
173(0xad)	PUSH1(0x60) ["0x40"]	3
175(0xaf)	MLOAD(0x51)	3	150(0x96)	MLOAD(0x51)	3
176(0xb0)	DUP1(0x80)	3	151(0x97)	DUP1(0x80)	3
177(0xb1)	SWAP2(0x91)	3	152(0x98)	SWAP2(0x91)	3
178(0xb2)	SUB(0x3)	3	153(0x99)	SUB(0x3)	3
179(0xb3)	SWAP1(0x90)	3	154(0x9a)	SWAP1(0x90)	3
180(0xb4)	REVERT(0xfd)	0	155(0x9b)	REVERT(0xfd)	0
181(0xb5)	JUMPDEST(0x5b)@0xb5	1	156(0x9c)	JUMPDEST(0x5b)@0x9c	1
182(0xb6)	JUMP(0x56)	8	157(0x9d)	JUMP(0x56)	8
	Total.Req:	125		Total.Cus:	74

The change provides a savings of 51 gas