Arithmetic processing device and control method of arithmetic processing device

An arithmetic processing device comprising:

• a memory;
• and
• a processor coupled to the memory and the processor configured to:
• calculate a constant multiplication value by multiplying a constant value obtained by dividing a first value by a natural logarithm of 2 and a data value stored in the memory;
• separate the constant multiplication value into an integer portion and a fractional portion;
• calculate a fractional power value expressed as a power of 2 having a value of the fractional portion of the constant multiplication value as an exponent;
• calculate an integer power value expressed as a power of 2 having a value obtained by multiplying a value of the integer portion of the constant multiplication value by a second value as an exponent;
• calculate a power addition value by adding the fractional power value and the integer power value;
• calculate a power subtraction value by subtracting the integer power value from the fractional power value;
• and
• calculate a division value by dividing the power subtraction value by the power addition value as a result of an execution of an arithmetic operation of a hyperbolic tangent function with the data value.