LiveValues.h

//===- LiveValues.h - Liveness information for LLVM IR Values. ------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the interface for the LLVM IR Value liveness
// analysis pass.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_ANALYSIS_LIVEVALUES_H
#define LLVM_ANALYSIS_LIVEVALUES_H

#include "llvm/Pass.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"

namespace llvm {

class DominatorTree;
class LoopInfo;
class Value;

class LiveValues : public FunctionPass {
  DominatorTree *DT;
  LoopInfo *LI;

  struct Memo {
    SmallPtrSet<const BasicBlock *, 4> Used;

    SmallPtrSet<const BasicBlock *, 4> LiveThrough;

    SmallPtrSet<const BasicBlock *, 4> Killed;
  };

  DenseMap<const Value *, Memo> Memos;

  Memo &getMemo(const Value *V);

  Memo &compute(const Value *V);

public:
  static char ID;
  LiveValues();

  virtual void getAnalysisUsage(AnalysisUsage &AU) const;
  virtual bool runOnFunction(Function &F);
  virtual void releaseMemory();

  bool isUsedInBlock(const Value *V, const BasicBlock *BB);

  bool isLiveThroughBlock(const Value *V, const BasicBlock *BB);

  bool isKilledInBlock(const Value *V, const BasicBlock *BB);
};

}  // end namespace llvm

#endif

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