In a 4-bit carry-lookahead adder, the overflow critical path typically involves the generation of carry lookahead signals and the calculation of the overflow flag. The specific number of logic gates in this path can vary depending on the design and implementation of the carry-lookahead adder. However, I can provide a general overview.
For each bit in the adder, you have logic gates to generate the carry lookahead signals (G and P), and these signals are used to calculate the carry-out (Cout) for that bit. This typically involves some combinational logic. Additionally, to calculate the overflow flag for the entire 4-bit adder, you would need to perform some additional logic operations.
The exact number of logic gates in the overflow critical path will depend on the specific design and optimizations used in the adder. It can vary among different implementations. For a detailed analysis of a particular design, you would need to examine the logic circuit and the specific logic gates used.