1. A method for generating test data used in evaluating a performance of a program, comprising: an input step of receiving, from an input device, a source program targeted for performance evaluation, sample data, and a generation parameter used for determining a size of the test data to be generated; a number-of-executions acquisition step of a processor executing the source program using the sample data and obtaining the number of executions for each of a plurality of statements in the source program; and a test data generation step of the processor generating, on the basis of the obtained number of executions, test data having a size that is a multiple of the generation parameter of a size of the sample data, the test data being such that the frequency of executions for each of the plurality of statements in the source program is the same as the frequency of executions for each of the plurality of statements when executing the source program using the sample data.