1. A system comprising: a processor comprising: a decoder to decode packed data instructions including a Single Instruction Multiple Data (SIMD) instruction specifying a first 64-bit operand comprising a first eight byte elements, a second 64-bit operand comprising a second eight byte elements, and an immediate value to specify a number (n) of bytes; a plurality of registers comprising at least one register to store the first eight byte elements and the second eight byte elements; and an execution unit coupled with the decoder and the plurality of registers, the execution unit in response to the SIMD instruction to store a 64-bit result in a destination indicated by the SIMD instruction, wherein the result is to include the number (n) least significant byte elements of the second operand in the number (n) most significant bytes of the result, concatenated with eight minus the number (n) most significant byte elements of the first operand in eight minus the number (n) least significant bytes of the result; a memory coupled with the processor; a bus coupled with the processor; a Bluetooth interface coupled with the processor; and a wireless interface coupled with the processor.