Strength Reduction
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 SideEffects.
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)