1. A processor comprising: a plurality of cores; a level 1 instruction cache to cache instructions; a level 1 data cache; a bus interface unit; a plurality of 128-bit registers; a decode unit to decode the instructions from the level 1 instruction cache including four Advanced Encryption Standard (AES) instructions of an instruction set of the processor, wherein each of the four AES instructions has a unique opcode, the four AES instructions including: a first AES encryption instruction that is to use a 128-bit source/destination register of the plurality of 128-bit registers and a 128-bit source register of the plurality of 128-bit registers, and a second AES encryption instruction that is to use a 128-bit source register of the plurality of 128-bit registers and a 128-bit destination register of the plurality of 128-bit registers; and an execution unit coupled to the decode unit, wherein: the first AES encryption instruction is to cause the execution unit to receive data from the 128-bit source/destination register and the 128-bit source register that is to be used by the first AES encryption instruction, perform operations for an AES single encryption round including a byte substitution, a shift rows, and an exclusive OR, but omitting a mix columns, and store a first result in the 128-bit source/destination register; and the second AES encryption instruction is to cause the execution unit to receive data from the 128-bit source register that is to be used by the second AES encryption instruction, perform operations including a mix columns, and store a second result in the 128-bit destination register that is to be used by the second AES encryption instruction.