COMPILER FOR OPTIMIZING PROGRAM

摘要

PROBLEM TO BE SOLVED: To optimize a process calculating a value to be assigned to a variable. SOLUTION: A compiler apparatus for optimizing a program includes: a range analysis unit for analyzing a range of a value assignable to the variable by the instruction, as a range of the variable in the case where the instruction is executed in terms of an instruction to assign a value to a variable in the program; a determination unit for determining if the execution result of the program does not change even if the instruction assigns any value in the range of the variable on the basis of the analyzed range of the variable; and a replacement unit for replacing the instruction to assign the value to the variable with an instruction to assign a constant value in the range of the variable to the variable on condition that the determination by the determination unit is formed. COPYRIGHT: (C)2009,JPO&INPIT