Information processing apparatus and information processing method

An information processing method for reading and executing a program stored in memory means, the method comprising the steps of

• outputting an address for reading the program to the memory means;
• decoding instructions read from the memory means in response to a control signal indicating a period in which the types of codes used in at least a field among fields constituting an instruction in the program are limited to a predetermined number or less;
• and
• performing processing corresponding to decoded results obtained by decoding the instructions,
• wherein in the step of decoding, the circuit configuration of a reconfigurable circuit is changed in response to the control signal so that the decoding is performed based on the relationship between codes in a field in which the types of codes used are limited and decoded results, the relationship being set so that the number of times of change of bit values in the field is reduced.

An information processing method for coding a program to enable an information processing device to execute the program, the information processing device being provided with an instruction decoder having a reconfigurable circuit, the method comprising the steps of:

• simulating execution of the program to obtain a history of instructions executed;
• extracting a routine in which the types of codes used in at least a field among fields constituting an instruction are limited to a predetermined number or less from the program based on the history;
• inserting an instruction for changing the circuit configuration of the reconfigurable circuit at the start and end of the routine;
• allocating codes so that the number of times of change of bit values in a field in which the types of codes used are limited is reduced for the routine;
• and
• converting a program obtained in the step of inserting an instruction to codes according to the allocation for the routine.