Squaring integers as a special case of multiplication

Currently, the gain in computational performance is achieved to a greater extent through the use of efficient algorithms than by increasing the clock frequency and processor bus width. This article is a logical continuation of https://www.cambridge.org/engage/coe/article-details/5eb717c5d7fc6400199f2159 About improving integer multiplication in processors, it separately discusses the optimization of the operation of squaring an integer and its comparison with the product of an integer by yourself.