exp_2 doesn't work when x is 63 about abdk-libraries-solidity HOT 2 CLOSED

Update

It just dawned on me that reverting is the expected behaviour. Max 64x64 is 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF, which is 2^63 - 1 (duh, these are signed numbers).

Yet, I keep the issue open because x should not be allowed to get bigger than 0x3f0000000000000000.

from abdk-libraries-solidity.

It is possible to figure out the exact upper limit for x beyond which the exp_2 function will throw and use it in the require statement, however this limit will make the code harder to read and the limit could become incorrect after further optimizations. Setting such precise limit would reduce gas cost only for x values in the narrow range between the true limit and 0x400000000000000000. Doesn't seem worth doing.

from abdk-libraries-solidity.