1. A non-transitory 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 including an antecedent cell group and a subsequent cell group, and representing an input constraint for the circuit by copying the combinational circuit in plural and coupling the plural copied combinational circuits and a selector so that the selector is between an antecedent combinational circuit and a subsequent combinational circuit among the plural copied combinational circuits and the plural copied combinational circuits and the selector are coupled 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, wherein the selector enables switching of an input to the subsequent combinational circuit to any one of an initial value input of a sequential circuit in the circuit and an output from the antecedent combinational circuit.