Editing Program optimization (section)

==Time taken for optimization==
Sometimes, the time taken to undertake optimization therein itself may be an issue.

Optimizing existing code usually does not add new features, and worse, it might add new [[Software bug|bugs]] in previously working code (as any change might). Because manually optimized code might sometimes have less "readability" than unoptimized code, optimization might impact maintainability of it as well. Optimization comes at a price and it is important to be sure that the investment is worthwhile.

An automatic optimizer (or [[optimizing compiler]], a program that performs code optimization) may itself have to be optimized, either to further improve the efficiency of its target programs or else speed up its own operation. A compilation performed with optimization "turned on" usually takes longer, although this is usually only a problem when programs are quite large.

In particular, for [[just-in-time compiler]]s the performance of the [[Run time environment|run time]] compile component, executing together with its target code, is the key to improving overall execution speed.