Patent ID: 7213243

Claim:
A computer-readable medium storing a program used to direct a computer to perform optimization process of the program, the process comprising: extracting data items from the program; laying out the data items in memory provided in the computer; extracting defined but unused data items from the extracted data items; determining whether or not a plurality of data items forming at least a part of a data item having a hierarchical structure in the unused data items can be merged into a new data item based on the layout result; and outputting a program in which the plurality of data items are merged into the new data item based on the determination result, wherein the number of unused data items is reduced by merging a plurality of unused data items forming a data item having a hierarchical structure into one data item based on the hierarchical level in the hierarchical structure and the arrangement of the data items in the memory; the program is optimized such that the necessary memory requirement during compilation or generation of a data item dictionary is reduced.