PURPOSE: To prevent the capacity of a memory for program from being increased by facilitating the reduction of a program size and reducing man-hour for design.

CONSTITUTION: This system is provided with a register value changing instruction analysis part 12 for analyzing the instruction sentence of a source program (SP) and outputting information such as the value of a register in the case of a register position changing instruction, register information storage part 2 for storing the information from this register value changing instruction analysis part 12, register valve output position discrimination part 13 and register value output part 31 for outputting the value of correspondent register of the register information storage part 2 into a program list (PL) when the instruction sentence of the SP is a register value output instruction. Based on the outputted PL, the prescribed instruction sentence of an object program is deleted.