25 lines
919 B
Solidity
25 lines
919 B
Solidity
pragma solidity 0.5.12;
|
|
|
|
library SafeMath128 {
|
|
function add(uint128 x, uint128 y) internal pure returns (uint128 z) {
|
|
require((z = x + y) >= x, "ds-math-add-overflow");
|
|
}
|
|
function sub(uint128 x, uint128 y) internal pure returns (uint128 z) {
|
|
require((z = x - y) <= x, "ds-math-sub-underflow");
|
|
}
|
|
function mul(uint128 x, uint128 y) internal pure returns (uint128 z) {
|
|
require(y == 0 || (z = x * y) / y == x, "ds-math-mul-overflow");
|
|
}
|
|
|
|
function oadd(uint128 w, uint128 x) internal pure returns (uint128 y, uint128 z) {
|
|
uint256 sum = uint256(w) + x;
|
|
z = uint128(sum / uint128(-1));
|
|
y = uint128(sum % uint128(-1));
|
|
}
|
|
function omul(uint128 w, uint128 x) internal pure returns (uint128 y, uint128 z) {
|
|
uint256 product = uint256(w) * x;
|
|
z = uint128(product / uint128(-1));
|
|
y = uint128(product % uint128(-1));
|
|
}
|
|
}
|