SSAPRE

java.lang.Object
- EDU.purdue.cs.bloat.trans.SSAPRE

```
public class SSAPRE
extends java.lang.Object
```
Perform partial redundancy elimination of a CFG in SSA form using the SSA-based algorithm described in:
```
     Fred Chow, Sun Chan, Robert Kennedy, Shin-Ming Liu, Raymond Lo,
     and Peng Tu, "A New Algorithm for Partial Redundancy Elimination
     based on SSA Form", Proc. PLDI '97: 273-286, 1997.
 
```
NOTE: The type for all occurrences of an inserted variable is the same as the type of the first occurrence of the expression the variable replaces. This type is guaranteed since we only group expression with equal types.

Field Summary

Fields
Modifier and Type	Field	Description
`protected FlowGraph`	`cfg`
`protected EditorContext`	`context`
`static boolean`	`DEBUG`
`protected ResizeableArrayList[]`	`kills`
`protected boolean[]`	`killsSorted`
`protected int`	`nextValueNumber`
`static boolean`	`NO_ACCESS_PATHS`
`static boolean`	`NO_PRECISE`
`static boolean`	`NO_THREAD`
`protected java.util.HashMap`	`phiRelated`
`protected SideEffectChecker`	`sideEffects`
`protected EDU.purdue.cs.bloat.trans.SSAPRE.ExprWorklist`	`worklist`

Constructor Summary

Constructors
Constructor Description

SSAPRE(FlowGraph cfg, EditorContext context)
Constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description

void transform()
Performs SSA-based partial redundency elimination (PRE) on a control flow graph.
- Methods inherited from class java.lang.Object
  clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEBUG
```
public static boolean DEBUG
```

NO_THREAD
```
public static boolean NO_THREAD
```

NO_PRECISE
```
public static boolean NO_PRECISE
```

NO_ACCESS_PATHS
```
public static boolean NO_ACCESS_PATHS
```

cfg
```
protected FlowGraph cfg
```

nextValueNumber
```
protected int nextValueNumber
```

context
```
protected EditorContext context
```

kills
```
protected ResizeableArrayList[] kills
```

killsSorted
```
protected boolean[] killsSorted
```

sideEffects

protected SideEffectChecker sideEffects

worklist

protected EDU.purdue.cs.bloat.trans.SSAPRE.ExprWorklist worklist

phiRelated
```
protected java.util.HashMap phiRelated
```

Constructor Detail
- SSAPRE
```
public SSAPRE(FlowGraph cfg,
              EditorContext context)
```
  Constructor.
  
  Parameters:
  
  cfg - Control flow graph on which to perform SSA-based PRE.
  
  context - The EditorContext containing all the classes that BLOAT knows about.

Method Detail
- transform
```
public void transform()
```
  Performs SSA-based partial redundency elimination (PRE) on a control flow graph.