CommonSubexpressionPromoter

```
public class CommonSubexpressionPromoter
extends java.lang.Object
```
This class is responsible for identifying and extracting common subexpressions within an expression. For example the expression (x/y/z = 3 or x/y/z = 4) is turned into (let $zz = x/y/z return ($zz = 3 or $zz = 4). For simplicity, in this initial version: (a) we extract at most one subexpression: the one that has the highest value of instances*cost. (b) we restrict the scope of the search for duplicates to that part of the expression tree that shares the same dynamic context (local variables, focus, etc).

Constructors
Constructor and Description
`CommonSubexpressionPromoter(OptimizerEE opt)`

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`Expression`	`promoteCommonSubexpressions(Expression in)` Search for duplicate subexpressions within an expression tree, and if one is found, generate a local variable bound to the common subexpression, replacing the original subexpression with a reference to the new local variable

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Class CommonSubexpressionPromoter