[12]How would you use two parallel adders to avoid the final round-up
addition in floating-point multiplication?
[30/10]This problem presents a way to reduce the number of addition steps
in floating-point addition from three to two using only a single adder.
a. [30]Let A and B be integers of opposite signs, with a and b their magnitudes.
Show that the following rules for manipulating the unsigned numbers a
and b gives A+B.
1. Complement one of the operands.
2. Use end-around carry to add the complemented operand and the other
(uncomplemented) one.
3. If there was a carry-out, the sign of the result is the sign associated with the
uncomplemented operand.
4. Otherwise, if there was no carry-out, complement the result, and give it the
sign of the complemented operand.
b. [10]Use the above to showhowsteps 2 and 4 in the floating-point addition
algorithm on page J-23 can be performed using only a single addition.