http://en.wikipedia.org/wiki/Superoptimization http://en.wikipedia.org/wiki/Superoptimization and/or the articles it cites should have been cited and consulted.

http://en.wikipedia.org/wiki/Superoptimization http://en.wikipedia.org/wiki/Superoptimization and/or the articles it cites should have been cited and consulted. Where mechanical discovery is not appropriate and you know what you want to accomplish (e.g., division by a constant integer at the cost of a multiplication or computing the number of one bits in a word) the "tricks" described in Warren's Hacker's Delight can be applied. Some, but not all optimizing compilers, look for sequences for which there is some known "trick".