Class LiveAnalysis

java.lang.Object

com.ibm.wala.cast.ir.ssa.analysis.LiveAnalysis

public class LiveAnalysis
extends Object

Author:

Julian Dolby

Live-value analysis for a method's IR (or ControlFlowGraph and SymbolTable) using a IKilldallFramework based implementation.

Pre-requisites - Knowledge of SSA form: control flow graphs, basic blocks, Phi instructions - Knowledge of data flow analysis theory.

Implementation notes:

- The solver uses node transfer functions only. - Performance: inverts the CFG to traverse backwards (backward analysis).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	LiveAnalysis.Result

Constructor Summary

Constructors

Constructor	Description
LiveAnalysis()

Method Summary

Modifier and Type	Method	Description
static LiveAnalysis.Result	perform(ControlFlowGraph<SSAInstruction,ISSABasicBlock> cfg, SymbolTable symtab)
static LiveAnalysis.Result	perform(ControlFlowGraph<SSAInstruction,ISSABasicBlock> cfg, SymbolTable symtab, BitVector considerLiveAtExit)
static LiveAnalysis.Result	perform(IR ir)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

LiveAnalysis

public LiveAnalysis()

Method Details

perform

public static LiveAnalysis.Result perform(IR ir)

perform

public static LiveAnalysis.Result perform(ControlFlowGraph<SSAInstruction,ISSABasicBlock> cfg,
 SymbolTable symtab)

perform

public static LiveAnalysis.Result perform(ControlFlowGraph<SSAInstruction,ISSABasicBlock> cfg,
 SymbolTable symtab,
 BitVector considerLiveAtExit)

Parameters:

considerLiveAtExit - given set (of variables) to consider to be live after the exit.

todo: used once in SSAConversion; Explain better the purpose.