Method and apparatus for saving checkpoint data while detecting and analyzing a loop structure

A save data discrimination method saves calculation results including an element which is periodically saved when a computer executes a program repeating the same arithmetic process. The method includes analyzing a loop structure of the program from a source code of the program to detect a main loop of the arithmetic process repeated in the program and a sub-loop included in the main loop, determining a point of entrance to the main loop as a checkpoint that is a point for saving data of the calculation results, and analyzing the contents of the arithmetic process described in the main loop to identify reference-first elements which are elements only referred to and elements defined after being referred to as data to be saved at the checkpoint determined at the point of entrance.