AbiStringsSplitCommasVsNone.md

AbiStringsSplitCommasVsNone_c.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0; // optimize 200

/**
 * @title AbiStringsSplitCommasVsNone
 * @author IllIllI
 */
contract AbiStringsSplitCommasVsNone {
    function test() external pure returns (bytes memory) {
        return abi.encodePacked("aaa", "bbb", "ccc");
    }
}

AbiStringsSplitCommasVsNone_n.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0; // optimize 200

/**
 * @title AbiStringsSplitCommasVsNone
 * @author IllIllI
 */
contract AbiStringsSplitCommasVsNone {
    function test() external pure returns (bytes memory) {
        return abi.encodePacked("aaa" "bbb" "ccc");
    }
}

Diff

diff --git a/AbiStringsSplitCommasVsNone_c.sol b/AbiStringsSplitCommasVsNone_n.sol
index 84dd713..aad1c72 100644
--- a/AbiStringsSplitCommasVsNone_c.sol
+++ b/AbiStringsSplitCommasVsNone_n.sol
@@ -7,7 +7,7 @@ pragma solidity ^0.8.0; // optimize 200
  */
 contract AbiStringsSplitCommasVsNone {
     function test() external pure returns (bytes memory) {
-        return abi.encodePacked("aaa", "bbb", "ccc");
+        return abi.encodePacked("aaa" "bbb" "ccc");
     }
 }
 

Compiled binary

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

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

Opcodes

PC.Orig	Operation.Orig	Gas.Orig	PC.New	Operation.New	Gas.New
137(0x89)	JUMP(0x56)	8	137(0x89)	JUMP(0x56)	8
138(0x8a)	JUMPDEST(0x5b)@0x8a	1	138(0x8a)	JUMPDEST(0x5b)@0x8a	1
			139(0x8b)	PUSH9(0x68) ["0x61","0x61",...	3
139(0x8b)	PUSH3(0x62) ["0x61","0x61",...	3
143(0x8f)	PUSH1(0x60) ["0xe8"]	3	149(0x95)	PUSH1(0x60) ["0xb8"]	3
145(0x91)	SHL(0x1b)	3	151(0x97)	SHL(0x1b)	3
146(0x92)	DUP2(0x81)	3	152(0x98)	DUP2(0x81)	3
147(0x93)	MSTORE(0x52)	3	153(0x99)	MSTORE(0x52)	3
148(0x94)	PUSH3(0x62) ["0x31","0x31",...	3
152(0x98)	PUSH1(0x60) ["0xe9"]	3
154(0x9a)	SHL(0x1b)	3
155(0x9b)	PUSH1(0x60) ["0x03"]	3
157(0x9d)	DUP3(0x82)	3
158(0x9e)	ADD(0x1)	3
159(0x9f)	MSTORE(0x52)	3
160(0xa0)	PUSH3(0x62) ["0x63","0x63",...	3
164(0xa4)	PUSH1(0x60) ["0xe8"]	3
166(0xa6)	SHL(0x1b)	3
167(0xa7)	PUSH1(0x60) ["0x06"]	3
169(0xa9)	DUP3(0x82)	3
170(0xaa)	ADD(0x1)	3
171(0xab)	MSTORE(0x52)	3
172(0xac)	PUSH1(0x60) ["0x09"]	3	154(0x9a)	PUSH1(0x60) ["0x09"]	3
174(0xae)	ADD(0x1)	3	156(0x9c)	ADD(0x1)	3
175(0xaf)	SWAP1(0x90)	3	157(0x9d)	SWAP1(0x90)	3
176(0xb0)	JUMP(0x56)	8	158(0x9e)	JUMP(0x56)	8
	Total.Orig:	83		Total.New:	41

The change provides a savings of 42 gas