function _validateAndFulfillBasicOrder(
    ...
    assembly {
            // Determine if offered item type == additional recipient item type.
            let offerTypeIsAdditionalRecipientsType := gt(route, 3)

            // If route > 3 additionalRecipientsToken is at 0xc4 else 0x24.
            additionalRecipientsToken := calldataload(
                add(
                    BasicOrder_considerationToken_cdPtr,
                    mul(offerTypeIsAdditionalRecipientsType, FiveWords) // FiveWords is the hardcoded distance
                )
            )
   ...
}   

struct BasicOrderParameters {
    address considerationToken; 
    uint256 considerationIdentifier; 
    uint256 considerationAmount; 
    address payable offerer; 
    address zone; 
    address offerToken; 
  ...
}
uint256 constant BasicOrder_considerationToken_cdPtr = 0x24;
uint256 constant BasicOrder_offerToken_cdPtr = 0xc4;         

+uint256 constant BasicOrder_Distance_oc_cdPtr = BasicOrder_offerToken_cdPtr - BasicOrder_considerationToken_cdPtr;

- mul(offerTypeIsAdditionalRecipientsType, FiveWords)
+ mul(offerTypeIsAdditionalRecipientsType, BasicOrder_Distance_oc_cdPtr) 
