Example #1
0
bool Scalarizer::visitGetElementPtrInst(GetElementPtrInst &GEPI) {
  VectorType *VT = dyn_cast<VectorType>(GEPI.getType());
  if (!VT)
    return false;

  IRBuilder<> Builder(&GEPI);
  unsigned NumElems = VT->getNumElements();
  unsigned NumIndices = GEPI.getNumIndices();

  Scatterer Base = scatter(&GEPI, GEPI.getOperand(0));

  SmallVector<Scatterer, 8> Ops;
  Ops.resize(NumIndices);
  for (unsigned I = 0; I < NumIndices; ++I)
    Ops[I] = scatter(&GEPI, GEPI.getOperand(I + 1));

  ValueVector Res;
  Res.resize(NumElems);
  for (unsigned I = 0; I < NumElems; ++I) {
    SmallVector<Value *, 8> Indices;
    Indices.resize(NumIndices);
    for (unsigned J = 0; J < NumIndices; ++J)
      Indices[J] = Ops[J][I];
    Res[I] = Builder.CreateGEP(GEPI.getSourceElementType(), Base[I], Indices,
                               GEPI.getName() + ".i" + Twine(I));
    if (GEPI.isInBounds())
      if (GetElementPtrInst *NewGEPI = dyn_cast<GetElementPtrInst>(Res[I]))
        NewGEPI->setIsInBounds();
  }
  gather(&GEPI, Res);
  return true;
}
// -- handle GetElementPtr instruction -- 
void UnsafeTypeCastingCheck::handleGetElementPtrInstruction (Instruction *inst) {
  GetElementPtrInst * ginst = dyn_cast<GetElementPtrInst>(inst); 
  if (ginst == NULL) 
    utccAbort("handleGetElementPtrInstruction cannot process with a non-getelementptr instruction");       
  Value *pt = ginst->getPointerOperand(); 

  UTCC_TYPE pt_ut_self = UH_UT; 
  UTCC_TYPE pt_ut_base = UH_UT; 
  UTCC_TYPE pt_ut_element = llvmT2utccT(ginst->getType()->getPointerElementType(), ginst); 

  if (isVisitedPointer(ginst)) pt_ut_self = queryPointedType(ginst); 
  if (isVisitedPointer(pt)) pt_ut_base = queryPointedType(pt); 

  setPointedType(ginst, utSaturate(pt_ut_element, 
				   utSaturate(pt_ut_self, pt_ut_base))); 
  setExprType(ginst, llvmT2utccT(ginst->getType(), ginst)); 
}
void GCInvariantVerifier::visitGetElementPtrInst(GetElementPtrInst &GEP) {
    Type *Ty = GEP.getType();
    if (!Ty->isPointerTy())
        return;
    unsigned AS = cast<PointerType>(Ty)->getAddressSpace();
    if (!isSpecialAS(AS))
        return;
    /* We're actually ok with GEPs here, as long as they don't feed into any
       uses. Upstream is currently still debating whether CAST(GEP) == GEP(CAST).
       In the frontend, we always perform CAST(GEP), so while we can enforce
       this invariant when we run directly after the frontend (Strong == 1),
       the optimizer will introduce the other form. Thus, we need to allow it
       while upstream hasn't decided whether the optimizer is allowed to
       introduce these.
       */
    if (Strong) {
        Check(AS != AddressSpace::Tracked,
             "GC tracked values may not appear in GEP expressions."
             " You may have to decay the value first", &GEP);
    }
}
Example #4
0
//
// Method: runOnModule()
//
// Description:
//  Entry point for this LLVM pass.
//  Find all GEPs, and simplify them.
//
// Inputs:
//  M - A reference to the LLVM module to transform
//
// Outputs:
//  M - The transformed LLVM module.
//
// Return value:
//  true  - The module was modified.
//  false - The module was not modified.
//
bool SimplifyGEP::runOnModule(Module& M) {
  TD = &getAnalysis<TargetData>();
  preprocess(M);
  for (Module::iterator F = M.begin(); F != M.end(); ++F){
    for (Function::iterator B = F->begin(), FE = F->end(); B != FE; ++B) {      
      for (BasicBlock::iterator I = B->begin(), BE = B->end(); I != BE; I++) {
        if(!(isa<GetElementPtrInst>(I)))
          continue;
        GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
        Value *PtrOp = GEP->getOperand(0);
        Value *StrippedPtr = PtrOp->stripPointerCasts();
        // Check if the GEP base pointer is enclosed in a cast
        if (StrippedPtr != PtrOp) {
          const PointerType *StrippedPtrTy =cast<PointerType>(StrippedPtr->getType());
          bool HasZeroPointerIndex = false;
          if (ConstantInt *C = dyn_cast<ConstantInt>(GEP->getOperand(1)))
            HasZeroPointerIndex = C->isZero();
          // Transform: GEP (bitcast [10 x i8]* X to [0 x i8]*), i32 0, ...
          // into     : GEP [10 x i8]* X, i32 0, ...
          //
          // Likewise, transform: GEP (bitcast i8* X to [0 x i8]*), i32 0, ...
          //           into     : GEP i8* X, ...
          // 
          // This occurs when the program declares an array extern like "int X[];"
          if (HasZeroPointerIndex) {
            const PointerType *CPTy = cast<PointerType>(PtrOp->getType());
            if (const ArrayType *CATy =
                dyn_cast<ArrayType>(CPTy->getElementType())) {
              // GEP (bitcast i8* X to [0 x i8]*), i32 0, ... ?
              if (CATy->getElementType() == StrippedPtrTy->getElementType()) {
                // -> GEP i8* X, ...
                SmallVector<Value*, 8> Idx(GEP->idx_begin()+1, GEP->idx_end());
                GetElementPtrInst *Res =
                  GetElementPtrInst::Create(StrippedPtr, Idx, GEP->getName(), GEP);
                Res->setIsInBounds(GEP->isInBounds());
                GEP->replaceAllUsesWith(Res);
                continue;
              }

              if (const ArrayType *XATy =
                  dyn_cast<ArrayType>(StrippedPtrTy->getElementType())){
                // GEP (bitcast [10 x i8]* X to [0 x i8]*), i32 0, ... ?
                if (CATy->getElementType() == XATy->getElementType()) {
                  // -> GEP [10 x i8]* X, i32 0, ...
                  // At this point, we know that the cast source type is a pointer
                  // to an array of the same type as the destination pointer
                  // array.  Because the array type is never stepped over (there
                  // is a leading zero) we can fold the cast into this GEP.
                  GEP->setOperand(0, StrippedPtr);
                  continue;
                }
              }
            }   
          } else if (GEP->getNumOperands() == 2) {
            // Transform things like:
            // %t = getelementptr i32* bitcast ([2 x i32]* %str to i32*), i32 %V
            // into:  %t1 = getelementptr [2 x i32]* %str, i32 0, i32 %V; bitcast
            Type *SrcElTy = StrippedPtrTy->getElementType();
            Type *ResElTy=cast<PointerType>(PtrOp->getType())->getElementType();
            if (TD && SrcElTy->isArrayTy() &&
                TD->getTypeAllocSize(cast<ArrayType>(SrcElTy)->getElementType()) ==
                TD->getTypeAllocSize(ResElTy)) {
              Value *Idx[2];
              Idx[0] = Constant::getNullValue(Type::getInt32Ty(GEP->getContext()));
              Idx[1] = GEP->getOperand(1);
              Value *NewGEP = GetElementPtrInst::Create(StrippedPtr, Idx,
                                                        GEP->getName(), GEP);
              // V and GEP are both pointer types --> BitCast
              GEP->replaceAllUsesWith(new BitCastInst(NewGEP, GEP->getType(), GEP->getName(), GEP));
              continue;
            }

            // Transform things like:
            // getelementptr i8* bitcast ([100 x double]* X to i8*), i32 %tmp
            //   (where tmp = 8*tmp2) into:
            // getelementptr [100 x double]* %arr, i32 0, i32 %tmp2; bitcast

            if (TD && SrcElTy->isArrayTy() && ResElTy->isIntegerTy(8)) {
              uint64_t ArrayEltSize =
                TD->getTypeAllocSize(cast<ArrayType>(SrcElTy)->getElementType());

              // Check to see if "tmp" is a scale by a multiple of ArrayEltSize.  We
              // allow either a mul, shift, or constant here.
              Value *NewIdx = 0;
              ConstantInt *Scale = 0;
              if (ArrayEltSize == 1) {
                NewIdx = GEP->getOperand(1);
                Scale = ConstantInt::get(cast<IntegerType>(NewIdx->getType()), 1);
              } else if (ConstantInt *CI = dyn_cast<ConstantInt>(GEP->getOperand(1))) {
                NewIdx = ConstantInt::get(CI->getType(), 1);
                Scale = CI;
              } else if (Instruction *Inst =dyn_cast<Instruction>(GEP->getOperand(1))){
                if (Inst->getOpcode() == Instruction::Shl &&
                    isa<ConstantInt>(Inst->getOperand(1))) {
                  ConstantInt *ShAmt = cast<ConstantInt>(Inst->getOperand(1));
                  uint32_t ShAmtVal = ShAmt->getLimitedValue(64);
                  Scale = ConstantInt::get(cast<IntegerType>(Inst->getType()),
                                           1ULL << ShAmtVal);
                  NewIdx = Inst->getOperand(0);
                } else if (Inst->getOpcode() == Instruction::Mul &&
                           isa<ConstantInt>(Inst->getOperand(1))) {
                  Scale = cast<ConstantInt>(Inst->getOperand(1));
                  NewIdx = Inst->getOperand(0);
                }
              }

              // If the index will be to exactly the right offset with the scale taken
              // out, perform the transformation. Note, we don't know whether Scale is
              // signed or not. We'll use unsigned version of division/modulo
              // operation after making sure Scale doesn't have the sign bit set.
              if (ArrayEltSize && Scale && Scale->getSExtValue() >= 0LL &&
                  Scale->getZExtValue() % ArrayEltSize == 0) {
                Scale = ConstantInt::get(Scale->getType(),
                                         Scale->getZExtValue() / ArrayEltSize);
                if (Scale->getZExtValue() != 1) {
                  Constant *C = ConstantExpr::getIntegerCast(Scale, NewIdx->getType(),
                                                             false /*ZExt*/);
                  NewIdx = BinaryOperator::Create(BinaryOperator::Mul, NewIdx, C, "idxscale");
                }

                // Insert the new GEP instruction.
                Value *Idx[2];
                Idx[0] = Constant::getNullValue(Type::getInt32Ty(GEP->getContext()));
                Idx[1] = NewIdx;
                Value *NewGEP = GetElementPtrInst::Create(StrippedPtr, Idx,
                                                          GEP->getName(), GEP);
                GEP->replaceAllUsesWith(new BitCastInst(NewGEP, GEP->getType(), GEP->getName(), GEP));
                continue;
              }
            }
          }
        }
      }
    }
  }

  return true;
}
bool PPCLoopPreIncPrep::runOnLoop(Loop *L) {
  bool MadeChange = false;

  // Only prep. the inner-most loop
  if (!L->empty())
    return MadeChange;

  DEBUG(dbgs() << "PIP: Examining: " << *L << "\n");

  BasicBlock *Header = L->getHeader();

  const PPCSubtarget *ST =
    TM ? TM->getSubtargetImpl(*Header->getParent()) : nullptr;

  unsigned HeaderLoopPredCount =
    std::distance(pred_begin(Header), pred_end(Header));

  // Collect buckets of comparable addresses used by loads and stores.
  SmallVector<Bucket, 16> Buckets;
  for (Loop::block_iterator I = L->block_begin(), IE = L->block_end();
       I != IE; ++I) {
    for (BasicBlock::iterator J = (*I)->begin(), JE = (*I)->end();
        J != JE; ++J) {
      Value *PtrValue;
      Instruction *MemI;

      if (LoadInst *LMemI = dyn_cast<LoadInst>(J)) {
        MemI = LMemI;
        PtrValue = LMemI->getPointerOperand();
      } else if (StoreInst *SMemI = dyn_cast<StoreInst>(J)) {
        MemI = SMemI;
        PtrValue = SMemI->getPointerOperand();
      } else if (IntrinsicInst *IMemI = dyn_cast<IntrinsicInst>(J)) {
        if (IMemI->getIntrinsicID() == Intrinsic::prefetch) {
          MemI = IMemI;
          PtrValue = IMemI->getArgOperand(0);
        } else continue;
      } else continue;

      unsigned PtrAddrSpace = PtrValue->getType()->getPointerAddressSpace();
      if (PtrAddrSpace)
        continue;

      // There are no update forms for Altivec vector load/stores.
      if (ST && ST->hasAltivec() &&
          PtrValue->getType()->getPointerElementType()->isVectorTy())
        continue;

      if (L->isLoopInvariant(PtrValue))
        continue;

      const SCEV *LSCEV = SE->getSCEVAtScope(PtrValue, L);
      if (const SCEVAddRecExpr *LARSCEV = dyn_cast<SCEVAddRecExpr>(LSCEV)) {
        if (LARSCEV->getLoop() != L)
          continue;
      } else {
        continue;
      }

      bool FoundBucket = false;
      for (auto &B : Buckets) {
        const SCEV *Diff = SE->getMinusSCEV(LSCEV, B.BaseSCEV);
        if (const auto *CDiff = dyn_cast<SCEVConstant>(Diff)) {
          B.Elements.push_back(BucketElement(CDiff, MemI));
          FoundBucket = true;
          break;
        }
      }

      if (!FoundBucket) {
        if (Buckets.size() == MaxVars)
          return MadeChange;
        Buckets.push_back(Bucket(LSCEV, MemI));
      }
    }
  }

  if (Buckets.empty())
    return MadeChange;

  BasicBlock *LoopPredecessor = L->getLoopPredecessor();
  // If there is no loop predecessor, or the loop predecessor's terminator
  // returns a value (which might contribute to determining the loop's
  // iteration space), insert a new preheader for the loop.
  if (!LoopPredecessor ||
      !LoopPredecessor->getTerminator()->getType()->isVoidTy()) {
    LoopPredecessor = InsertPreheaderForLoop(L, DT, LI, PreserveLCSSA);
    if (LoopPredecessor)
      MadeChange = true;
  }
  if (!LoopPredecessor)
    return MadeChange;

  DEBUG(dbgs() << "PIP: Found " << Buckets.size() << " buckets\n");

  SmallSet<BasicBlock *, 16> BBChanged;
  for (unsigned i = 0, e = Buckets.size(); i != e; ++i) {
    // The base address of each bucket is transformed into a phi and the others
    // are rewritten as offsets of that variable.

    // We have a choice now of which instruction's memory operand we use as the
    // base for the generated PHI. Always picking the first instruction in each
    // bucket does not work well, specifically because that instruction might
    // be a prefetch (and there are no pre-increment dcbt variants). Otherwise,
    // the choice is somewhat arbitrary, because the backend will happily
    // generate direct offsets from both the pre-incremented and
    // post-incremented pointer values. Thus, we'll pick the first non-prefetch
    // instruction in each bucket, and adjust the recurrence and other offsets
    // accordingly. 
    for (int j = 0, je = Buckets[i].Elements.size(); j != je; ++j) {
      if (auto *II = dyn_cast<IntrinsicInst>(Buckets[i].Elements[j].Instr))
        if (II->getIntrinsicID() == Intrinsic::prefetch)
          continue;

      // If we'd otherwise pick the first element anyway, there's nothing to do.
      if (j == 0)
        break;

      // If our chosen element has no offset from the base pointer, there's
      // nothing to do.
      if (!Buckets[i].Elements[j].Offset ||
          Buckets[i].Elements[j].Offset->isZero())
        break;

      const SCEV *Offset = Buckets[i].Elements[j].Offset;
      Buckets[i].BaseSCEV = SE->getAddExpr(Buckets[i].BaseSCEV, Offset);
      for (auto &E : Buckets[i].Elements) {
        if (E.Offset)
          E.Offset = cast<SCEVConstant>(SE->getMinusSCEV(E.Offset, Offset));
        else
          E.Offset = cast<SCEVConstant>(SE->getNegativeSCEV(Offset));
      }

      std::swap(Buckets[i].Elements[j], Buckets[i].Elements[0]);
      break;
    }

    const SCEVAddRecExpr *BasePtrSCEV =
      cast<SCEVAddRecExpr>(Buckets[i].BaseSCEV);
    if (!BasePtrSCEV->isAffine())
      continue;

    DEBUG(dbgs() << "PIP: Transforming: " << *BasePtrSCEV << "\n");
    assert(BasePtrSCEV->getLoop() == L &&
           "AddRec for the wrong loop?");

    // The instruction corresponding to the Bucket's BaseSCEV must be the first
    // in the vector of elements.
    Instruction *MemI = Buckets[i].Elements.begin()->Instr;
    Value *BasePtr = GetPointerOperand(MemI);
    assert(BasePtr && "No pointer operand");

    Type *I8Ty = Type::getInt8Ty(MemI->getParent()->getContext());
    Type *I8PtrTy = Type::getInt8PtrTy(MemI->getParent()->getContext(),
      BasePtr->getType()->getPointerAddressSpace());

    const SCEV *BasePtrStartSCEV = BasePtrSCEV->getStart();
    if (!SE->isLoopInvariant(BasePtrStartSCEV, L))
      continue;

    const SCEVConstant *BasePtrIncSCEV =
      dyn_cast<SCEVConstant>(BasePtrSCEV->getStepRecurrence(*SE));
    if (!BasePtrIncSCEV)
      continue;
    BasePtrStartSCEV = SE->getMinusSCEV(BasePtrStartSCEV, BasePtrIncSCEV);
    if (!isSafeToExpand(BasePtrStartSCEV, *SE))
      continue;

    DEBUG(dbgs() << "PIP: New start is: " << *BasePtrStartSCEV << "\n");

    PHINode *NewPHI = PHINode::Create(I8PtrTy, HeaderLoopPredCount,
      MemI->hasName() ? MemI->getName() + ".phi" : "",
      Header->getFirstNonPHI());

    SCEVExpander SCEVE(*SE, Header->getModule()->getDataLayout(), "pistart");
    Value *BasePtrStart = SCEVE.expandCodeFor(BasePtrStartSCEV, I8PtrTy,
      LoopPredecessor->getTerminator());

    // Note that LoopPredecessor might occur in the predecessor list multiple
    // times, and we need to add it the right number of times.
    for (pred_iterator PI = pred_begin(Header), PE = pred_end(Header);
         PI != PE; ++PI) {
      if (*PI != LoopPredecessor)
        continue;

      NewPHI->addIncoming(BasePtrStart, LoopPredecessor);
    }

    Instruction *InsPoint = &*Header->getFirstInsertionPt();
    GetElementPtrInst *PtrInc = GetElementPtrInst::Create(
        I8Ty, NewPHI, BasePtrIncSCEV->getValue(),
        MemI->hasName() ? MemI->getName() + ".inc" : "", InsPoint);
    PtrInc->setIsInBounds(IsPtrInBounds(BasePtr));
    for (pred_iterator PI = pred_begin(Header), PE = pred_end(Header);
         PI != PE; ++PI) {
      if (*PI == LoopPredecessor)
        continue;

      NewPHI->addIncoming(PtrInc, *PI);
    }

    Instruction *NewBasePtr;
    if (PtrInc->getType() != BasePtr->getType())
      NewBasePtr = new BitCastInst(PtrInc, BasePtr->getType(),
        PtrInc->hasName() ? PtrInc->getName() + ".cast" : "", InsPoint);
    else
      NewBasePtr = PtrInc;

    if (Instruction *IDel = dyn_cast<Instruction>(BasePtr))
      BBChanged.insert(IDel->getParent());
    BasePtr->replaceAllUsesWith(NewBasePtr);
    RecursivelyDeleteTriviallyDeadInstructions(BasePtr);

    // Keep track of the replacement pointer values we've inserted so that we
    // don't generate more pointer values than necessary.
    SmallPtrSet<Value *, 16> NewPtrs;
    NewPtrs.insert( NewBasePtr);

    for (auto I = std::next(Buckets[i].Elements.begin()),
         IE = Buckets[i].Elements.end(); I != IE; ++I) {
      Value *Ptr = GetPointerOperand(I->Instr);
      assert(Ptr && "No pointer operand");
      if (NewPtrs.count(Ptr))
        continue;

      Instruction *RealNewPtr;
      if (!I->Offset || I->Offset->getValue()->isZero()) {
        RealNewPtr = NewBasePtr;
      } else {
        Instruction *PtrIP = dyn_cast<Instruction>(Ptr);
        if (PtrIP && isa<Instruction>(NewBasePtr) &&
            cast<Instruction>(NewBasePtr)->getParent() == PtrIP->getParent())
          PtrIP = nullptr;
        else if (isa<PHINode>(PtrIP))
          PtrIP = &*PtrIP->getParent()->getFirstInsertionPt();
        else if (!PtrIP)
          PtrIP = I->Instr;

        GetElementPtrInst *NewPtr = GetElementPtrInst::Create(
            I8Ty, PtrInc, I->Offset->getValue(),
            I->Instr->hasName() ? I->Instr->getName() + ".off" : "", PtrIP);
        if (!PtrIP)
          NewPtr->insertAfter(cast<Instruction>(PtrInc));
        NewPtr->setIsInBounds(IsPtrInBounds(Ptr));
        RealNewPtr = NewPtr;
      }

      if (Instruction *IDel = dyn_cast<Instruction>(Ptr))
        BBChanged.insert(IDel->getParent());

      Instruction *ReplNewPtr;
      if (Ptr->getType() != RealNewPtr->getType()) {
        ReplNewPtr = new BitCastInst(RealNewPtr, Ptr->getType(),
          Ptr->hasName() ? Ptr->getName() + ".cast" : "");
        ReplNewPtr->insertAfter(RealNewPtr);
      } else
        ReplNewPtr = RealNewPtr;

      Ptr->replaceAllUsesWith(ReplNewPtr);
      RecursivelyDeleteTriviallyDeadInstructions(Ptr);

      NewPtrs.insert(RealNewPtr);
    }

    MadeChange = true;
  }

  for (Loop::block_iterator I = L->block_begin(), IE = L->block_end();
       I != IE; ++I) {
    if (BBChanged.count(*I))
      DeleteDeadPHIs(*I);
  }

  return MadeChange;
}
Example #6
0
bool PPCLoopPreIncPrep::runOnLoop(Loop *L) {
  bool MadeChange = false;

  if (!DL)
    return MadeChange;

  // Only prep. the inner-most loop
  if (!L->empty())
    return MadeChange;

  BasicBlock *Header = L->getHeader();

  const PPCSubtarget *ST =
    TM ? TM->getSubtargetImpl(*Header->getParent()) : nullptr;

  unsigned HeaderLoopPredCount = 0;
  for (pred_iterator PI = pred_begin(Header), PE = pred_end(Header);
       PI != PE; ++PI) {
    ++HeaderLoopPredCount;
  }

  // Collect buckets of comparable addresses used by loads and stores.
  typedef std::multimap<const SCEV *, Instruction *, SCEVLess> Bucket;
  SmallVector<Bucket, 16> Buckets;
  for (Loop::block_iterator I = L->block_begin(), IE = L->block_end();
       I != IE; ++I) {
    for (BasicBlock::iterator J = (*I)->begin(), JE = (*I)->end();
        J != JE; ++J) {
      Value *PtrValue;
      Instruction *MemI;

      if (LoadInst *LMemI = dyn_cast<LoadInst>(J)) {
        MemI = LMemI;
        PtrValue = LMemI->getPointerOperand();
      } else if (StoreInst *SMemI = dyn_cast<StoreInst>(J)) {
        MemI = SMemI;
        PtrValue = SMemI->getPointerOperand();
      } else if (IntrinsicInst *IMemI = dyn_cast<IntrinsicInst>(J)) {
        if (IMemI->getIntrinsicID() == Intrinsic::prefetch) {
          MemI = IMemI;
          PtrValue = IMemI->getArgOperand(0);
        } else continue;
      } else continue;

      unsigned PtrAddrSpace = PtrValue->getType()->getPointerAddressSpace();
      if (PtrAddrSpace)
        continue;

      // There are no update forms for Altivec vector load/stores.
      if (ST && ST->hasAltivec() &&
          PtrValue->getType()->getPointerElementType()->isVectorTy())
        continue;

      if (L->isLoopInvariant(PtrValue))
        continue;

      const SCEV *LSCEV = SE->getSCEV(PtrValue);
      if (!isa<SCEVAddRecExpr>(LSCEV))
        continue;

      bool FoundBucket = false;
      for (unsigned i = 0, e = Buckets.size(); i != e; ++i)
        for (Bucket::iterator K = Buckets[i].begin(), KE = Buckets[i].end();
             K != KE; ++K) {
          const SCEV *Diff = SE->getMinusSCEV(K->first, LSCEV);
          if (isa<SCEVConstant>(Diff)) {
            Buckets[i].insert(std::make_pair(LSCEV, MemI));
            FoundBucket = true;
            break;
          }
        }

      if (!FoundBucket) {
        Buckets.push_back(Bucket(SCEVLess(SE)));
        Buckets[Buckets.size()-1].insert(std::make_pair(LSCEV, MemI));
      }
    }
  }

  if (Buckets.empty() || Buckets.size() > MaxVars)
    return MadeChange;

  BasicBlock *LoopPredecessor = L->getLoopPredecessor();
  // If there is no loop predecessor, or the loop predecessor's terminator
  // returns a value (which might contribute to determining the loop's
  // iteration space), insert a new preheader for the loop.
  if (!LoopPredecessor ||
      !LoopPredecessor->getTerminator()->getType()->isVoidTy())
    LoopPredecessor = InsertPreheaderForLoop(L, this);
  if (!LoopPredecessor)
    return MadeChange;

  SmallSet<BasicBlock *, 16> BBChanged;
  for (unsigned i = 0, e = Buckets.size(); i != e; ++i) {
    // The base address of each bucket is transformed into a phi and the others
    // are rewritten as offsets of that variable.

    const SCEVAddRecExpr *BasePtrSCEV =
      cast<SCEVAddRecExpr>(Buckets[i].begin()->first);
    if (!BasePtrSCEV->isAffine())
      continue;

    Instruction *MemI = Buckets[i].begin()->second;
    Value *BasePtr = GetPointerOperand(MemI);
    assert(BasePtr && "No pointer operand");

    Type *I8PtrTy = Type::getInt8PtrTy(MemI->getParent()->getContext(),
      BasePtr->getType()->getPointerAddressSpace());

    const SCEV *BasePtrStartSCEV = BasePtrSCEV->getStart();
    if (!SE->isLoopInvariant(BasePtrStartSCEV, L))
      continue;

    const SCEVConstant *BasePtrIncSCEV =
      dyn_cast<SCEVConstant>(BasePtrSCEV->getStepRecurrence(*SE));
    if (!BasePtrIncSCEV)
      continue;
    BasePtrStartSCEV = SE->getMinusSCEV(BasePtrStartSCEV, BasePtrIncSCEV);
    if (!isSafeToExpand(BasePtrStartSCEV, *SE))
      continue;

    PHINode *NewPHI = PHINode::Create(I8PtrTy, HeaderLoopPredCount,
      MemI->hasName() ? MemI->getName() + ".phi" : "",
      Header->getFirstNonPHI());

    SCEVExpander SCEVE(*SE, "pistart");
    Value *BasePtrStart = SCEVE.expandCodeFor(BasePtrStartSCEV, I8PtrTy,
      LoopPredecessor->getTerminator());

    // Note that LoopPredecessor might occur in the predecessor list multiple
    // times, and we need to add it the right number of times.
    for (pred_iterator PI = pred_begin(Header), PE = pred_end(Header);
         PI != PE; ++PI) {
      if (*PI != LoopPredecessor)
        continue;

      NewPHI->addIncoming(BasePtrStart, LoopPredecessor);
    }

    Instruction *InsPoint = Header->getFirstInsertionPt();
    GetElementPtrInst *PtrInc =
      GetElementPtrInst::Create(NewPHI, BasePtrIncSCEV->getValue(),
        MemI->hasName() ? MemI->getName() + ".inc" : "", InsPoint);
    PtrInc->setIsInBounds(IsPtrInBounds(BasePtr));
    for (pred_iterator PI = pred_begin(Header), PE = pred_end(Header);
         PI != PE; ++PI) {
      if (*PI == LoopPredecessor)
        continue;

      NewPHI->addIncoming(PtrInc, *PI);
    }

    Instruction *NewBasePtr;
    if (PtrInc->getType() != BasePtr->getType())
      NewBasePtr = new BitCastInst(PtrInc, BasePtr->getType(),
        PtrInc->hasName() ? PtrInc->getName() + ".cast" : "", InsPoint);
    else
      NewBasePtr = PtrInc;

    if (Instruction *IDel = dyn_cast<Instruction>(BasePtr))
      BBChanged.insert(IDel->getParent());
    BasePtr->replaceAllUsesWith(NewBasePtr);
    RecursivelyDeleteTriviallyDeadInstructions(BasePtr);

    Value *LastNewPtr = NewBasePtr;
    for (Bucket::iterator I = std::next(Buckets[i].begin()),
         IE = Buckets[i].end(); I != IE; ++I) {
      Value *Ptr = GetPointerOperand(I->second);
      assert(Ptr && "No pointer operand");
      if (Ptr == LastNewPtr)
        continue;

      Instruction *RealNewPtr;
      const SCEVConstant *Diff =
        cast<SCEVConstant>(SE->getMinusSCEV(I->first, BasePtrSCEV));
      if (Diff->isZero()) {
        RealNewPtr = NewBasePtr;
      } else {
        Instruction *PtrIP = dyn_cast<Instruction>(Ptr);
        if (PtrIP && isa<Instruction>(NewBasePtr) &&
            cast<Instruction>(NewBasePtr)->getParent() == PtrIP->getParent())
          PtrIP = 0;
        else if (isa<PHINode>(PtrIP))
          PtrIP = PtrIP->getParent()->getFirstInsertionPt();
        else if (!PtrIP)
          PtrIP = I->second;
  
        GetElementPtrInst *NewPtr =
          GetElementPtrInst::Create(PtrInc, Diff->getValue(),
            I->second->hasName() ? I->second->getName() + ".off" : "", PtrIP);
        if (!PtrIP)
          NewPtr->insertAfter(cast<Instruction>(PtrInc));
        NewPtr->setIsInBounds(IsPtrInBounds(Ptr));
        RealNewPtr = NewPtr;
      }

      if (Instruction *IDel = dyn_cast<Instruction>(Ptr))
        BBChanged.insert(IDel->getParent());

      Instruction *ReplNewPtr;
      if (Ptr->getType() != RealNewPtr->getType()) {
        ReplNewPtr = new BitCastInst(RealNewPtr, Ptr->getType(),
          Ptr->hasName() ? Ptr->getName() + ".cast" : "");
        ReplNewPtr->insertAfter(RealNewPtr);
      } else
        ReplNewPtr = RealNewPtr;

      Ptr->replaceAllUsesWith(ReplNewPtr);
      RecursivelyDeleteTriviallyDeadInstructions(Ptr);

      LastNewPtr = RealNewPtr;
    }

    MadeChange = true;
  }

  for (Loop::block_iterator I = L->block_begin(), IE = L->block_end();
       I != IE; ++I) {
    if (BBChanged.count(*I))
      DeleteDeadPHIs(*I);
  }

  return MadeChange;
}
Value *PropagateJuliaAddrspaces::LiftPointer(Value *V, Type *LocTy, Instruction *InsertPt) {
    SmallVector<Value *, 4> Stack;
    Value *CurrentV = V;
    // Follow pointer casts back, see if we're based on a pointer in
    // an untracked address space, in which case we're allowed to drop
    // intermediate addrspace casts.
    while (true) {
        Stack.push_back(CurrentV);
        if (isa<BitCastInst>(CurrentV))
            CurrentV = cast<BitCastInst>(CurrentV)->getOperand(0);
        else if (isa<AddrSpaceCastInst>(CurrentV)) {
            CurrentV = cast<AddrSpaceCastInst>(CurrentV)->getOperand(0);
            if (!isSpecialAS(getValueAddrSpace(CurrentV)))
                break;
        }
        else if (isa<GetElementPtrInst>(CurrentV)) {
            if (LiftingMap.count(CurrentV)) {
                CurrentV = LiftingMap[CurrentV];
                break;
            } else if (Visited.count(CurrentV)) {
                return nullptr;
            }
            Visited.insert(CurrentV);
            CurrentV = cast<GetElementPtrInst>(CurrentV)->getOperand(0);
        } else
            break;
    }
    if (!CurrentV->getType()->isPointerTy())
        return nullptr;
    if (isSpecialAS(getValueAddrSpace(CurrentV)))
        return nullptr;
    // Ok, we're allowed to change the address space of this load, go back and
    // reconstitute any GEPs in the new address space.
    for (Value *V : llvm::reverse(Stack)) {
        GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V);
        if (!GEP)
            continue;
        if (LiftingMap.count(GEP)) {
            CurrentV = LiftingMap[GEP];
            continue;
        }
        GetElementPtrInst *NewGEP = cast<GetElementPtrInst>(GEP->clone());
        ToInsert.push_back(std::make_pair(NewGEP, GEP));
        Type *GEPTy = GEP->getSourceElementType();
        Type *NewRetTy = cast<PointerType>(GEP->getType())->getElementType()->getPointerTo(getValueAddrSpace(CurrentV));
        NewGEP->mutateType(NewRetTy);
        if (cast<PointerType>(CurrentV->getType())->getElementType() != GEPTy) {
            auto *BCI = new BitCastInst(CurrentV, GEPTy->getPointerTo());
            ToInsert.push_back(std::make_pair(BCI, NewGEP));
            CurrentV = BCI;
        }
        NewGEP->setOperand(GetElementPtrInst::getPointerOperandIndex(), CurrentV);
        LiftingMap[GEP] = NewGEP;
        CurrentV = NewGEP;
    }
    if (LocTy && cast<PointerType>(CurrentV->getType())->getElementType() != LocTy) {
        auto *BCI = new BitCastInst(CurrentV, LocTy->getPointerTo());
        ToInsert.push_back(std::make_pair(BCI, InsertPt));
        CurrentV = BCI;
    }
    return CurrentV;
}
Value *llvm::ConvertExpressionToType(Value *V, const Type *Ty, 
                                     ValueMapCache &VMC, const TargetData &TD) {
  if (V->getType() == Ty) return V;  // Already where we need to be?

  ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(V);
  if (VMCI != VMC.ExprMap.end()) {
    const Value *GV = VMCI->second;
    const Type *GTy = VMCI->second->getType();
    assert(VMCI->second->getType() == Ty);

    if (Instruction *I = dyn_cast<Instruction>(V))
      ValueHandle IHandle(VMC, I);  // Remove I if it is unused now!

    return VMCI->second;
  }

  DEBUG(std::cerr << "CETT: " << (void*)V << " " << *V);

  Instruction *I = dyn_cast<Instruction>(V);
  if (I == 0) {
    Constant *CPV = cast<Constant>(V);
    // Constants are converted by constant folding the cast that is required.
    // We assume here that all casts are implemented for constant prop.
    Value *Result = ConstantExpr::getCast(CPV, Ty);
    // Add the instruction to the expression map
    //VMC.ExprMap[V] = Result;
    return Result;
  }


  BasicBlock *BB = I->getParent();
  std::string Name = I->getName();  if (!Name.empty()) I->setName("");
  Instruction *Res;     // Result of conversion

  ValueHandle IHandle(VMC, I);  // Prevent I from being removed!
  
  Constant *Dummy = Constant::getNullValue(Ty);

  switch (I->getOpcode()) {
  case Instruction::Cast:
    assert(VMC.NewCasts.count(ValueHandle(VMC, I)) == 0);
    Res = new CastInst(I->getOperand(0), Ty, Name);
    VMC.NewCasts.insert(ValueHandle(VMC, Res));
    break;
    
  case Instruction::Add:
  case Instruction::Sub:
    Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
                                 Dummy, Dummy, Name);
    VMC.ExprMap[I] = Res;   // Add node to expression eagerly

    Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC, TD));
    Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), Ty, VMC, TD));
    break;

  case Instruction::Shl:
  case Instruction::Shr:
    Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), Dummy,
                        I->getOperand(1), Name);
    VMC.ExprMap[I] = Res;
    Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC, TD));
    break;

  case Instruction::Load: {
    LoadInst *LI = cast<LoadInst>(I);

    Res = new LoadInst(Constant::getNullValue(PointerType::get(Ty)), Name);
    VMC.ExprMap[I] = Res;
    Res->setOperand(0, ConvertExpressionToType(LI->getPointerOperand(),
                                               PointerType::get(Ty), VMC, TD));
    assert(Res->getOperand(0)->getType() == PointerType::get(Ty));
    assert(Ty == Res->getType());
    assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
    break;
  }

  case Instruction::PHI: {
    PHINode *OldPN = cast<PHINode>(I);
    PHINode *NewPN = new PHINode(Ty, Name);

    VMC.ExprMap[I] = NewPN;   // Add node to expression eagerly
    while (OldPN->getNumOperands()) {
      BasicBlock *BB = OldPN->getIncomingBlock(0);
      Value *OldVal = OldPN->getIncomingValue(0);
      ValueHandle OldValHandle(VMC, OldVal);
      OldPN->removeIncomingValue(BB, false);
      Value *V = ConvertExpressionToType(OldVal, Ty, VMC, TD);
      NewPN->addIncoming(V, BB);
    }
    Res = NewPN;
    break;
  }

  case Instruction::Malloc: {
    Res = ConvertMallocToType(cast<MallocInst>(I), Ty, Name, VMC, TD);
    break;
  }

  case Instruction::GetElementPtr: {
    // GetElementPtr's are directly convertible to a pointer type if they have
    // a number of zeros at the end.  Because removing these values does not
    // change the logical offset of the GEP, it is okay and fair to remove them.
    // This can change this:
    //   %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0  ; <%List **>
    //   %t2 = cast %List * * %t1 to %List *
    // into
    //   %t2 = getelementptr %Hosp * %hosp, ubyte 4           ; <%List *>
    // 
    GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);

    // Check to see if there are zero elements that we can remove from the
    // index array.  If there are, check to see if removing them causes us to
    // get to the right type...
    //
    std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
    const Type *BaseType = GEP->getPointerOperand()->getType();
    const Type *PVTy = cast<PointerType>(Ty)->getElementType();
    Res = 0;
    while (!Indices.empty() &&
           Indices.back() == Constant::getNullValue(Indices.back()->getType())){
      Indices.pop_back();
      if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
        if (Indices.size() == 0)
          Res = new CastInst(GEP->getPointerOperand(), BaseType); // NOOP CAST
        else
          Res = new GetElementPtrInst(GEP->getPointerOperand(), Indices, Name);
        break;
      }
    }

    if (Res == 0 && GEP->getNumOperands() == 2 &&
        GEP->getType() == PointerType::get(Type::SByteTy)) {
      
      // Otherwise, we can convert a GEP from one form to the other iff the
      // current gep is of the form 'getelementptr sbyte*, unsigned N
      // and we could convert this to an appropriate GEP for the new type.
      //
      const PointerType *NewSrcTy = PointerType::get(PVTy);
      BasicBlock::iterator It = I;

      // Check to see if 'N' is an expression that can be converted to
      // the appropriate size... if so, allow it.
      //
      std::vector<Value*> Indices;
      const Type *ElTy = ConvertibleToGEP(NewSrcTy, I->getOperand(1),
                                          Indices, TD, &It);
      if (ElTy) {        
        assert(ElTy == PVTy && "Internal error, setup wrong!");
        Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
                                    Indices, Name);
        VMC.ExprMap[I] = Res;
        Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
                                                   NewSrcTy, VMC, TD));
      }
    }

    // Otherwise, it could be that we have something like this:
    //     getelementptr [[sbyte] *] * %reg115, uint %reg138    ; [sbyte]**
    // and want to convert it into something like this:
    //     getelemenptr [[int] *] * %reg115, uint %reg138      ; [int]**
    //
    if (Res == 0) {
      const PointerType *NewSrcTy = PointerType::get(PVTy);
      std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
      Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
                                  Indices, Name);
      VMC.ExprMap[I] = Res;
      Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
                                                 NewSrcTy, VMC, TD));
    }


    assert(Res && "Didn't find match!");
    break;
  }

  case Instruction::Call: {
    assert(!isa<Function>(I->getOperand(0)));

    // If this is a function pointer, we can convert the return type if we can
    // convert the source function pointer.
    //
    const PointerType *PT = cast<PointerType>(I->getOperand(0)->getType());
    const FunctionType *FT = cast<FunctionType>(PT->getElementType());
    std::vector<const Type *> ArgTys(FT->param_begin(), FT->param_end());
    const FunctionType *NewTy =
      FunctionType::get(Ty, ArgTys, FT->isVarArg());
    const PointerType *NewPTy = PointerType::get(NewTy);
    if (Ty == Type::VoidTy)
      Name = "";  // Make sure not to name calls that now return void!

    Res = new CallInst(Constant::getNullValue(NewPTy),
                       std::vector<Value*>(I->op_begin()+1, I->op_end()),
                       Name);
    VMC.ExprMap[I] = Res;
    Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),NewPTy,VMC,TD));
    break;
  }
  default:
    assert(0 && "Expression convertible, but don't know how to convert?");
    return 0;
  }

  assert(Res->getType() == Ty && "Didn't convert expr to correct type!");

  BB->getInstList().insert(I, Res);

  // Add the instruction to the expression map
  VMC.ExprMap[I] = Res;


  unsigned NumUses = I->use_size();
  for (unsigned It = 0; It < NumUses; ) {
    unsigned OldSize = NumUses;
    Value::use_iterator UI = I->use_begin();
    std::advance(UI, It);
    ConvertOperandToType(*UI, I, Res, VMC, TD);
    NumUses = I->use_size();
    if (NumUses == OldSize) ++It;
  }

  DEBUG(std::cerr << "ExpIn: " << (void*)I << " " << *I
                  << "ExpOut: " << (void*)Res << " " << *Res);

  return Res;
}
// ExpressionConvertibleToType - Return true if it is possible
bool llvm::ExpressionConvertibleToType(Value *V, const Type *Ty,
                                 ValueTypeCache &CTMap, const TargetData &TD) {
  // Expression type must be holdable in a register.
  if (!Ty->isFirstClassType())
    return false;
  
  ValueTypeCache::iterator CTMI = CTMap.find(V);
  if (CTMI != CTMap.end()) return CTMI->second == Ty;

  // If it's a constant... all constants can be converted to a different
  // type.
  //
  if (isa<Constant>(V) && !isa<GlobalValue>(V))
    return true;
  
  CTMap[V] = Ty;
  if (V->getType() == Ty) return true;  // Expression already correct type!

  Instruction *I = dyn_cast<Instruction>(V);
  if (I == 0) return false;              // Otherwise, we can't convert!

  switch (I->getOpcode()) {
  case Instruction::Cast:
    // We can convert the expr if the cast destination type is losslessly
    // convertible to the requested type.
    if (!Ty->isLosslesslyConvertibleTo(I->getType())) return false;

    // We also do not allow conversion of a cast that casts from a ptr to array
    // of X to a *X.  For example: cast [4 x %List *] * %val to %List * *
    //
    if (const PointerType *SPT = 
        dyn_cast<PointerType>(I->getOperand(0)->getType()))
      if (const PointerType *DPT = dyn_cast<PointerType>(I->getType()))
        if (const ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
          if (AT->getElementType() == DPT->getElementType())
            return false;
    break;

  case Instruction::Add:
  case Instruction::Sub:
    if (!Ty->isInteger() && !Ty->isFloatingPoint()) return false;
    if (!ExpressionConvertibleToType(I->getOperand(0), Ty, CTMap, TD) ||
        !ExpressionConvertibleToType(I->getOperand(1), Ty, CTMap, TD))
      return false;
    break;
  case Instruction::Shr:
    if (!Ty->isInteger()) return false;
    if (Ty->isSigned() != V->getType()->isSigned()) return false;
    // FALL THROUGH
  case Instruction::Shl:
    if (!Ty->isInteger()) return false;
    if (!ExpressionConvertibleToType(I->getOperand(0), Ty, CTMap, TD))
      return false;
    break;

  case Instruction::Load: {
    LoadInst *LI = cast<LoadInst>(I);
    if (!ExpressionConvertibleToType(LI->getPointerOperand(),
                                     PointerType::get(Ty), CTMap, TD))
      return false;
    break;                                     
  }
  case Instruction::PHI: {
    PHINode *PN = cast<PHINode>(I);
    // Be conservative if we find a giant PHI node.
    if (PN->getNumIncomingValues() > 32) return false;

    for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
      if (!ExpressionConvertibleToType(PN->getIncomingValue(i), Ty, CTMap, TD))
        return false;
    break;
  }

  case Instruction::Malloc:
    if (!MallocConvertibleToType(cast<MallocInst>(I), Ty, CTMap, TD))
      return false;
    break;

  case Instruction::GetElementPtr: {
    // GetElementPtr's are directly convertible to a pointer type if they have
    // a number of zeros at the end.  Because removing these values does not
    // change the logical offset of the GEP, it is okay and fair to remove them.
    // This can change this:
    //   %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0  ; <%List **>
    //   %t2 = cast %List * * %t1 to %List *
    // into
    //   %t2 = getelementptr %Hosp * %hosp, ubyte 4           ; <%List *>
    // 
    GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
    const PointerType *PTy = dyn_cast<PointerType>(Ty);
    if (!PTy) return false;  // GEP must always return a pointer...
    const Type *PVTy = PTy->getElementType();

    // Check to see if there are zero elements that we can remove from the
    // index array.  If there are, check to see if removing them causes us to
    // get to the right type...
    //
    std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
    const Type *BaseType = GEP->getPointerOperand()->getType();
    const Type *ElTy = 0;

    while (!Indices.empty() &&
           Indices.back() == Constant::getNullValue(Indices.back()->getType())){
      Indices.pop_back();
      ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices, true);
      if (ElTy == PVTy)
        break;  // Found a match!!
      ElTy = 0;
    }

    if (ElTy) break;   // Found a number of zeros we can strip off!

    // Otherwise, we can convert a GEP from one form to the other iff the
    // current gep is of the form 'getelementptr sbyte*, long N
    // and we could convert this to an appropriate GEP for the new type.
    //
    if (GEP->getNumOperands() == 2 &&
        GEP->getType() == PointerType::get(Type::SByteTy)) {

      // Do not Check to see if our incoming pointer can be converted
      // to be a ptr to an array of the right type... because in more cases than
      // not, it is simply not analyzable because of pointer/array
      // discrepancies.  To fix this, we will insert a cast before the GEP.
      //

      // Check to see if 'N' is an expression that can be converted to
      // the appropriate size... if so, allow it.
      //
      std::vector<Value*> Indices;
      const Type *ElTy = ConvertibleToGEP(PTy, I->getOperand(1), Indices, TD);
      if (ElTy == PVTy) {
        if (!ExpressionConvertibleToType(I->getOperand(0),
                                         PointerType::get(ElTy), CTMap, TD))
          return false;  // Can't continue, ExConToTy might have polluted set!
        break;
      }
    }

    // Otherwise, it could be that we have something like this:
    //     getelementptr [[sbyte] *] * %reg115, long %reg138    ; [sbyte]**
    // and want to convert it into something like this:
    //     getelemenptr [[int] *] * %reg115, long %reg138      ; [int]**
    //
    if (GEP->getNumOperands() == 2 && 
        PTy->getElementType()->isSized() &&
        TD.getTypeSize(PTy->getElementType()) == 
        TD.getTypeSize(GEP->getType()->getElementType())) {
      const PointerType *NewSrcTy = PointerType::get(PVTy);
      if (!ExpressionConvertibleToType(I->getOperand(0), NewSrcTy, CTMap, TD))
        return false;
      break;
    }

    return false;   // No match, maybe next time.
  }

  case Instruction::Call: {
    if (isa<Function>(I->getOperand(0)))
      return false;  // Don't even try to change direct calls.

    // If this is a function pointer, we can convert the return type if we can
    // convert the source function pointer.
    //
    const PointerType *PT = cast<PointerType>(I->getOperand(0)->getType());
    const FunctionType *FT = cast<FunctionType>(PT->getElementType());
    std::vector<const Type *> ArgTys(FT->param_begin(), FT->param_end());
    const FunctionType *NewTy =
      FunctionType::get(Ty, ArgTys, FT->isVarArg());
    if (!ExpressionConvertibleToType(I->getOperand(0),
                                     PointerType::get(NewTy), CTMap, TD))
      return false;
    break;
  }
  default:
    return false;
  }

  // Expressions are only convertible if all of the users of the expression can
  // have this value converted.  This makes use of the map to avoid infinite
  // recursion.
  //
  for (Value::use_iterator It = I->use_begin(), E = I->use_end(); It != E; ++It)
    if (!OperandConvertibleToType(*It, I, Ty, CTMap, TD))
      return false;

  return true;
}
Example #10
0
bool Aa::LowerGepPass::runOnFunction(Function &F)
{
  const llvm::Type *ptr_int_type = TD->getIntPtrType(F.getContext());

  for (Function::iterator bi = F.begin(), be = F.end(); bi != be; ++bi) {
    BasicBlock *bb = bi;

    BasicBlock::iterator ii = bb->begin();
    while (ii != bb->end()) {
      GetElementPtrInst *gep = dyn_cast<GetElementPtrInst>(ii);
      BasicBlock::iterator gi = ii++;
      if (!gep) {
	continue;
      }

      for (llvm::Value::use_iterator ui = gep->use_begin(), ue = gep->use_end();
           ui != ue; ++ui) {
        Use &u = ui.getUse();

        IOCode ioc = get_io_code(u);

        if (ioc == NOT_IO)
          continue;

        u.set(CastInst::CreatePointerCast(gep->getPointerOperand()
                                          , gep->getType()
                                          , "", gep));
      }

      assert(gep->hasIndices() && "GEP without indices??");
      llvm::Value *ptr = gep->getPointerOperand();
      const Type *ctype = ptr->getType();

      // deal with the base pointer first
      llvm::Value *base = gep->getPointerOperand();
      std::string base_name = gep->getNameStr() + ".base";
      llvm::Value *address = new PtrToIntInst(base, ptr_int_type, base_name + ".cast", gi);
      
      unsigned i = 0;
      for (User::op_iterator oi = gep->idx_begin(), oe = gep->idx_end();
	   oi != oe; ++oi, ++i) {
	llvm::Value *index = *oi;
	llvm::Value *offset = NULL;

	std::stringstream index_name;
	index_name << gep->getNameStr() << ".idx." << i;
	
	if (const SequentialType *qtype = dyn_cast<SequentialType>(ctype)) {
	  // multiply index by size of element

	  unsigned element_size = getTypePaddedSize(TD, qtype->getElementType());
	  const llvm::IntegerType *index_type = cast<IntegerType>(index->getType());
	  ConstantInt *cint = ConstantInt::get(index_type, element_size);
	  assert(cint && "uh oh!");
	  offset = BinaryOperator::Create(Instruction::Mul
					  , cint
					  , index
					  , index_name.str()
					  , gi);
	  ctype = qtype->getElementType();
	} else if (const StructType *stype = dyn_cast<StructType>(ctype)) {
	  // calculate offset into the struct

	  const StructLayout *layout = TD->getStructLayout(stype);
	  unsigned idx = cast<ConstantInt>(index)->getValue().getZExtValue();
	  unsigned struct_offset = layout->getElementOffset(idx);
	  offset = ConstantInt::get(ptr_int_type, struct_offset);
	  ctype = stype->getElementType(idx);
	} else
	  assert(false && "unhandled offset into composite type");
	
	// add offset to the address

	assert(address && "uh oh!");
	std::stringstream add_name;
	add_name << gep->getNameStr() << ".lvl." << i;
	
	if (offset->getType() != address->getType()) {
	  offset = CastInst::CreateIntegerCast(offset, address->getType()
					       , false, offset->getName() + ".resized"
					       , gi);
	}
	
	address = BinaryOperator::Create(Instruction::Add
					 , address, offset
					 , add_name.str(), gi);
      }

      if (address->getType() != ptr_int_type)
	address = CastInst::CreateIntegerCast(address, ptr_int_type
					      , false, address->getName() + ".final", gi);
      Instruction *new_ptr = new IntToPtrInst(address, gep->getType()
					  , gep->getName() + ".cast");
      ReplaceInstWithInst(bb->getInstList(), gi, new_ptr);
    }
  }

  return true;
}