An arithmetic logic unit comprises multiple (N) adjustment circuits and a multiplier-accumulator. Each of the N adjustment circuits obtains an input floating-point number of a pre-selected input type, and converts the input number to one or more output floating-point numbers of an operation type and precision. The multiplier-accumulator is connected to the N adjustment circuits, and is configured to perform operations on input floating-point numbers of the operation type. The multiplier-accumulator receives a group of floating-point numbers of the operation type from the N adjustment circuits as inputs, performs an operation on the group of floating-point numbers, and generates an operation result floating-point number of the operation type. The multiplier-accumulator then converts the operation result floating-point number to an output floating-point number of a desired type different from the operation type.