Program rewrite device, storage medium, and program rewrite method

1. A program rewrite device, comprising:

a memory; and

a processor coupled to the memory and the processor configured to:

rewrite a program to output a first output group by performing operations for a first variable among a plurality of variables with a plurality of data types,

rewrite the program to output a second output group by performing operations for a second variable among the plurality of variables with a plurality of data types,

identify, from the first output group and the second output group, a third output group that satisfied that calculation results of the first variable obtained from the first output group and the second variable obtained from the second output group fall within a predetermined error range as a result of executing the rewritten programs,

determine a data type that corresponds to the third output group as a use data type,

output a program in which the use data type is set for each of the plurality of variables,

rewrite the program to perform condition branch determination with a plurality of data types,

rewrite the program to be able to copy an execution process to two execution processes on a true branch side and on a false branch side in a case of executing the program after the condition branch determination, and

rewrite the program to stop use of a data type in which the condition branch determination becomes false in the process on the true branch side, and to stop use of a data type in which the condition branch determination becomes true in the process on the false branch side.

2. The program rewrite device according to claim 1 , wherein the processor configured to:

change a name of a function at a call position according to the use data type at the call position of the function; and

output the program to which the function is added in accordance with the name of the function.

3. A non-transitory computer-readable storage medium storing a program that causes a computer to execute a process, the process comprising:

rewriting a program to output a first output group by performing operations for a first variable among a plurality of variables with a plurality of data types;

rewriting the program to output a second output group by performing operations for a second variable among the plurality of variables with a plurality of data types;

identifying, from the first output group and the second output group, a third output group that satisfied that calculation results of the first variable obtained from the first output group and the second variable obtained from the second output croup fall within a predetermined error range as a result of executing the rewritten programs;

determining a data type that corresponds to the third output group as a use data type;

outputting a program in which the use data type is set for each of the plurality of variables;

rewriting the program to perform condition branch determination with a plurality of data types;

rewriting the program to be able to copy an execution process to two execution processes on a true branch side and on a false branch side in a case of executing the program after the condition branch determination; and

rewriting the program to stop use of a data type in which the condition branch determination becomes false in the process on the true branch side, and to stop use of a data type in which the condition branch determination becomes true in the process on the false branch side.

4. A program rewrite method executed by a computer, the method comprising:

rewriting a program to output a first output group by performing operations for a first variable among a plurality of variables with a plurality of data types;

rewriting the program to output a second output group by performing operations for a second variable among the plurality of variables with a plurality of data types;

identifying, from the first output group and the second output group, a third output group that satisfied that calculation results of the first variable obtained from the first output group and the second variable obtained from the second output group fall within a predetermined error range as a result of executing the rewritten programs;

determining a data type that corresponds to the third output group as a use data type;

outputting a program in which the use data type is set for each of the plurality of variables;

rewriting the program to perform condition branch determination with a plurality of data types;

rewriting the program to be able to copy an execution process to two execution processes on a true branch side and on a false branch side in a case of executing the program after the condition branch determination; and

rewriting the program to stop use of a data type in which the condition branch determination becomes false in the process on the true branch side, and to stop use of a data type in which the condition branch determination becomes true in the process on the false branch side.

5. The program rewrite method according to claim 4 , wherein the method comprising:

changing a name of a function at a call position according to a situation of the use data type at the call position of the function; and

outputting the program to which the function is added in accordance with the name of the function.