You could probably use the A+D pre-adder to do one addition, and the final adder to do the second. You would have to set the B input to 1 to generate (A+D)*1 + C. All these inputs are bigger than 22 bits.
This can be done in one clock, but will have a maximum frequency probably around the 300MHz range. If you can pipeline it, it would be able to go faster.
That being said, you can also do this operation in the fabric, just by using A+B+C - it will not be much slower (addition using the fabric carry chain is pretty fast).