diff options
Diffstat (limited to 'packages/contracts/src/2.0.0/protocol/Exchange')
-rw-r--r-- | packages/contracts/src/2.0.0/protocol/Exchange/libs/LibMath.sol | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibMath.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibMath.sol index 3e70d1b60..c4aa2abb5 100644 --- a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibMath.sol +++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibMath.sol @@ -107,6 +107,7 @@ contract LibMath is if (target == 0 || numerator == 0) { return false; } + // Otherwise, we want the relative rounding error to be strictly // less than 0.1%. // The relative error is `remainder / numerator * target`. @@ -120,4 +121,32 @@ contract LibMath is isError = safeMul(1000, remainder) >= safeMul(numerator, target); return isError; } + + /// @dev Checks if rounding error > 0.1%. + /// @param numerator Numerator. + /// @param denominator Denominator. + /// @param target Value to multiply with numerator/denominator. + /// @return Rounding error is present. + function isRoundingErrorCeil( + uint256 numerator, + uint256 denominator, + uint256 target + ) + internal + pure + returns (bool isError) + { + require(denominator > 0, "DIVISION_BY_ZERO"); + + if (target == 0 || numerator == 0) { + return false; + } + uint256 remainder = mulmod(target, numerator, denominator); + if (remainder == 0) { + return false; + } + remainder = safeSub(denominator, remainder); + isError = safeMul(1000, remainder) >= safeMul(numerator, target); + return isError; + } } |