A processor includes a functional unit, and a set of vector registers coupled to the functional unit. The processor executes an instruction to cause the functional unit to classify each value of multiple floating-point values stored in a first vector register of the set of vector registers, and store in a second vector register of the set of registers multiple elements that each indicate a respective classification of a respective value of the multiple floating-point values. The first and second vector registers may be source and destination vector registers, and each may be specified by the instruction. The classify and store operations may also be specified by the instruction. The instruction may be embodied on a device-readable medium.