1. A computer-readable recording medium storing therein an LSI analysis computer program that causes a computer to execute: extracting a combinational circuit from a circuit having the combinational circuit and a cell group storing input/output values of the combinational circuit; generating an input constraint circuit representing an input constraint for the circuit by copying the combinational circuit in plural and coupling the resulting combinational circuits in series between an antecedent cell group and a subsequent cell group, each of which has the same configuration as the cell group; and an output unit that outputs the input constraint circuit.