1. In a data processing system of the type having at least a pair of processor units, a one of processor units being operable to perform floating point computations on first and second operands, each having an exponent field and a fractional field, the other processor units being operable to perform other data processing tasks in parallel with floating point computations being performed by the one processor unit, a method of performing floating point computations, the method comprising the steps of: forming, for each different type of floating point computation to be performed by the one processor unit, floating point exception causing criteria; comparing a combination of the exponent fields of the first and the second operands to the floating point exception causing criteria for the floating point computation to be performed; generating a floating point exception prediction signal when the comparing step indicates, pursuant to the criteria used, the possibility that an exception will occur; temporarily halting operation of the other processor unit in response to existence of the floating point exception prediction signal; performing the floating computation; and resuming operation of the other processor unit if the computation does not result in an actual floating point operation.