The SWAP operations provide the ability to exchange stack items. There are 16 SWAP instructions available, and with each instruction, the stack items are removed and placed incrementally up to 17 items depending on the type of opcode used.
|
Mnemonic |
Value |
POP |
PUSH |
Gas |
Description |
|
SWAP1 . . . SWAP16 |
0x90 ...0x9f |
X |
Y |
3 |
Used to swap the Nth stack item, where N is the number corresponding to the SWAP instruction used. X and Y are the items removed and placed on the stack, respectively. |
