We theoretically analyze the performance of all-optical multifunctional AND, NOT-OR (NOR), and exclusive-NOR (XNOR) logic gates at 80 Gb s−1 using return-to-zero data format in a compact scheme based on semiconductor optical amplifiers (SOAs). The AND logic gate is formed by incorporating two SOAs in a Mach–Zehnder interferometer and the NOR logic gate is formed using a single SOA followed by a series delayed interferometer. Then an additional logic gate, XNOR, is realized by by the combination of the AND and NOR output logic channels. Therefore, three logic operations are performed using a compact scheme within few resources. The quality factor (QF) of the considered Boolean functions against the key operational parameters of the input data and SOA is examined, considering the effects of the amplified spontaneous emission, operating temperature, and phase noise for more realistic results. The results of Wolfram Mathematica show that three logic functions, AND, NOR, and XNOR, can simultaneously be realized at 80 Gb s−1 using the employed compact scheme with high QF.