PHITransAddr.h

//===- PHITransAddr.h - PHI Translation for Addresses -----------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the PHITransAddr class.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_ANALYSIS_PHITRANSADDR_H
#define LLVM_ANALYSIS_PHITRANSADDR_H

#include "llvm/Instruction.h"
#include "llvm/ADT/SmallVector.h"

namespace llvm {
  class DominatorTree;
  class TargetData;
  
class PHITransAddr {
  Value *Addr;
  
  const TargetData *TD;
  
  SmallVector<Instruction*, 4> InstInputs;
public:
  PHITransAddr(Value *addr, const TargetData *td) : Addr(addr), TD(td) {
    // If the address is an instruction, the whole thing is considered an input.
    if (Instruction *I = dyn_cast<Instruction>(Addr))
      InstInputs.push_back(I);
  }
  
  Value *getAddr() const { return Addr; }
  
  bool NeedsPHITranslationFromBlock(BasicBlock *BB) const {
    // We do need translation if one of our input instructions is defined in
    // this block.
    for (unsigned i = 0, e = InstInputs.size(); i != e; ++i)
      if (InstInputs[i]->getParent() == BB)
        return true;
    return false;
  }
  
  bool IsPotentiallyPHITranslatable() const;
  
  bool PHITranslateValue(BasicBlock *CurBB, BasicBlock *PredBB,
                         const DominatorTree *DT);
  
  Value *PHITranslateWithInsertion(BasicBlock *CurBB, BasicBlock *PredBB,
                                   const DominatorTree &DT,
                                   SmallVectorImpl<Instruction*> &NewInsts);
  
  void dump() const;
  
  bool Verify() const;
private:
  Value *PHITranslateSubExpr(Value *V, BasicBlock *CurBB, BasicBlock *PredBB,
                             const DominatorTree *DT);
  
  Value *InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB,
                                    BasicBlock *PredBB, const DominatorTree &DT,
                                    SmallVectorImpl<Instruction*> &NewInsts);
  
  Value *AddAsInput(Value *V) {
    // If V is an instruction, it is now an input.
    if (Instruction *VI = dyn_cast<Instruction>(V))
      InstInputs.push_back(VI);
    return V;
  }
  
};

} // end namespace llvm

#endif

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