Performs a code elimination by DCE (dead code elimination) more effectively in optimizing a program by compiling. In an example embodiment, a method invocation to be a processing target is determined based on a state of a use of an object reference in a method invocation in an execution program. The method invocation, which has been determined to be a processing target, is inline-expanded. The instance variable of an object in the inline-expanded method invocation is scalarized, and dead code elimination is performed for the execution program, to which an inline-expansion and a scalarization is performed.