https://www.evm.codes/?fork=cancun#07:
Note the overflow semantic when $−2^{255}$ is negated.
This is a controversial statement for this opcode.
There is no such statement in https://ethereum.github.io/yellowpaper/paper.pdf.
If needed, you may look deeper into implementation details:
The main point is that SDIV comment—
"Note the overflow semantic when $−2^{255}$ is negated."—
refers to an overflow case.
In contrast, SMOD does not overflow because its arithmetic logic disregards the sign of the second operand.
https://www.evm.codes/?fork=cancun#07:
This is a controversial statement for this opcode.
There is no such statement in https://ethereum.github.io/yellowpaper/paper.pdf.
If needed, you may look deeper into implementation details:
opSdiv: https://github.com/ethereum/go-ethereum/blob/master/core/vm/instructions.go#L53
Sdiv: https://github.com/holiman/uint256/blob/master/uint256.go#L789
opSmod: https://github.com/ethereum/go-ethereum/blob/master/core/vm/instructions.go#L65
Smod: https://github.com/holiman/uint256/blob/master/uint256.go#L662C1-L682C2
The main point is that SDIV comment—$−2^{255}$ is negated."—
"Note the overflow semantic when
refers to an overflow case.
In contrast, SMOD does not overflow because its arithmetic logic disregards the sign of the second operand.