Speculative execution

In computer science and processor design, speculative execution or speculation is a design characteristic where a processor is able to perform potentially useful work by guessing what work is needed next, compute them prematurely, and immediately applying or discarding the results when the work's necessity is eventually known. Since the 21st century, speculation is commonly seen on superscalarcentral processors (CPUs), as an optimization technique to increase its performance. It is often used in combination with branch prediction to increase the accuracy of the guessing process.