Simplified: Replacing '*' with repeated '+'. 

Examples:
* Moving calculation of loop-invariant expressions out of the loop.
* Replacing a multiplication with a loop index with repeated addition of the factor.

Often done automatically by a compiler (at least partly). This is often limited by SideEffect''''''s.

Articles:
* A Balanced Code Placement Framework (2000) http://portal.acm.org/citation.cfm?id=365161&coll=portal&dl=ACM&CFID=38913265&CFTOKEN=16431788 (fairly advanced)

----
CategoryOptimization CategoryCompilers