function uintDiv(uint256 u, int256 f) internal pure returns (uint256) {
  if (f < 0) revert InvalidFixedPoint(); //@audit
  // multiply `u` by FIXED_1 to cancel out the built-in FIXED_1 in f
  return uint256((u.toInt256() * FixedMath0x.FIXED_1) / f);
}
    function uintDiv(uint256 u, int256 f) internal pure returns (uint256) {
-        if (f < 0) revert InvalidFixedPoint();
+        if (f <= 0) revert InvalidFixedPoint();
        // multiply `u` by FIXED_1 to cancel out the built-in FIXED_1 in f
        return uint256((u.toInt256() * FixedMath0x.FIXED_1) / f);
    }
