A shift calculator including a first shifter includes a right shifter configured to perform a right shift of 0 to 3 bits and a left shifter configured to perform a left shift of 0 to 3 bits, on input data of which a data width is N bits, in accordance with left/right selection signals, based on a shift amount of 3 bits or smaller out of an input shift amount, a rotator configured to perform a right rotate shift of 0 to N−4 bits or a left rotate shift of 0 to N−4 bits, on output data from said first shifter, in accordance with said left/right selection signals, based on a shift amount of 4 bits or greater out of the input shift amount, and a mask unit configured to perform mask processing in 4-bit increments on output data from said rotator based on mask signals.