Update LLVM for 3.5 rebase (r209712).

Change-Id: I149556c940fb7dc92d075273c87ff584f400941f
diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
index c2b862a..356803a 100644
--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -19,6 +19,8 @@
 using namespace llvm;
 using namespace PatternMatch;
 
+#define DEBUG_TYPE "instcombine"
+
 /// DecomposeSimpleLinearExpr - Analyze 'Val', seeing if it is a simple linear
 /// expression.  If so, decompose it, returning some value X, such that Val is
 /// X*Scale+Offset.
@@ -79,7 +81,7 @@
 Instruction *InstCombiner::PromoteCastOfAllocation(BitCastInst &CI,
                                                    AllocaInst &AI) {
   // This requires DataLayout to get the alloca alignment and size information.
-  if (!DL) return 0;
+  if (!DL) return nullptr;
 
   PointerType *PTy = cast<PointerType>(CI.getType());
 
@@ -89,26 +91,26 @@
   // Get the type really allocated and the type casted to.
   Type *AllocElTy = AI.getAllocatedType();
   Type *CastElTy = PTy->getElementType();
-  if (!AllocElTy->isSized() || !CastElTy->isSized()) return 0;
+  if (!AllocElTy->isSized() || !CastElTy->isSized()) return nullptr;
 
   unsigned AllocElTyAlign = DL->getABITypeAlignment(AllocElTy);
   unsigned CastElTyAlign = DL->getABITypeAlignment(CastElTy);
-  if (CastElTyAlign < AllocElTyAlign) return 0;
+  if (CastElTyAlign < AllocElTyAlign) return nullptr;
 
   // If the allocation has multiple uses, only promote it if we are strictly
   // increasing the alignment of the resultant allocation.  If we keep it the
   // same, we open the door to infinite loops of various kinds.
-  if (!AI.hasOneUse() && CastElTyAlign == AllocElTyAlign) return 0;
+  if (!AI.hasOneUse() && CastElTyAlign == AllocElTyAlign) return nullptr;
 
   uint64_t AllocElTySize = DL->getTypeAllocSize(AllocElTy);
   uint64_t CastElTySize = DL->getTypeAllocSize(CastElTy);
-  if (CastElTySize == 0 || AllocElTySize == 0) return 0;
+  if (CastElTySize == 0 || AllocElTySize == 0) return nullptr;
 
   // If the allocation has multiple uses, only promote it if we're not
   // shrinking the amount of memory being allocated.
   uint64_t AllocElTyStoreSize = DL->getTypeStoreSize(AllocElTy);
   uint64_t CastElTyStoreSize = DL->getTypeStoreSize(CastElTy);
-  if (!AI.hasOneUse() && CastElTyStoreSize < AllocElTyStoreSize) return 0;
+  if (!AI.hasOneUse() && CastElTyStoreSize < AllocElTyStoreSize) return nullptr;
 
   // See if we can satisfy the modulus by pulling a scale out of the array
   // size argument.
@@ -120,10 +122,10 @@
   // If we can now satisfy the modulus, by using a non-1 scale, we really can
   // do the xform.
   if ((AllocElTySize*ArraySizeScale) % CastElTySize != 0 ||
-      (AllocElTySize*ArrayOffset   ) % CastElTySize != 0) return 0;
+      (AllocElTySize*ArrayOffset   ) % CastElTySize != 0) return nullptr;
 
   unsigned Scale = (AllocElTySize*ArraySizeScale)/CastElTySize;
-  Value *Amt = 0;
+  Value *Amt = nullptr;
   if (Scale == 1) {
     Amt = NumElements;
   } else {
@@ -141,6 +143,7 @@
   AllocaInst *New = AllocaBuilder.CreateAlloca(CastElTy, Amt);
   New->setAlignment(AI.getAlignment());
   New->takeName(&AI);
+  New->setUsedWithInAlloca(AI.isUsedWithInAlloca());
 
   // If the allocation has multiple real uses, insert a cast and change all
   // things that used it to use the new cast.  This will also hack on CI, but it
@@ -169,7 +172,7 @@
 
   // Otherwise, it must be an instruction.
   Instruction *I = cast<Instruction>(V);
-  Instruction *Res = 0;
+  Instruction *Res = nullptr;
   unsigned Opc = I->getOpcode();
   switch (Opc) {
   case Instruction::Add:
@@ -245,11 +248,11 @@
   Instruction::CastOps firstOp = Instruction::CastOps(CI->getOpcode());
   Instruction::CastOps secondOp = Instruction::CastOps(opcode);
   Type *SrcIntPtrTy = DL && SrcTy->isPtrOrPtrVectorTy() ?
-    DL->getIntPtrType(SrcTy) : 0;
+    DL->getIntPtrType(SrcTy) : nullptr;
   Type *MidIntPtrTy = DL && MidTy->isPtrOrPtrVectorTy() ?
-    DL->getIntPtrType(MidTy) : 0;
+    DL->getIntPtrType(MidTy) : nullptr;
   Type *DstIntPtrTy = DL && DstTy->isPtrOrPtrVectorTy() ?
-    DL->getIntPtrType(DstTy) : 0;
+    DL->getIntPtrType(DstTy) : nullptr;
   unsigned Res = CastInst::isEliminableCastPair(firstOp, secondOp, SrcTy, MidTy,
                                                 DstTy, SrcIntPtrTy, MidIntPtrTy,
                                                 DstIntPtrTy);
@@ -318,7 +321,7 @@
         return NV;
   }
 
-  return 0;
+  return nullptr;
 }
 
 /// CanEvaluateTruncated - Return true if we can evaluate the specified
@@ -470,7 +473,7 @@
   }
 
   // Transform trunc(lshr (zext A), Cst) to eliminate one type conversion.
-  Value *A = 0; ConstantInt *Cst = 0;
+  Value *A = nullptr; ConstantInt *Cst = nullptr;
   if (Src->hasOneUse() &&
       match(Src, m_LShr(m_ZExt(m_Value(A)), m_ConstantInt(Cst)))) {
     // We have three types to worry about here, the type of A, the source of
@@ -502,7 +505,7 @@
                                      ConstantExpr::getTrunc(Cst, CI.getType()));
   }
 
-  return 0;
+  return nullptr;
 }
 
 /// transformZExtICmp - Transform (zext icmp) to bitwise / integer operations
@@ -550,7 +553,7 @@
       // If Op1C some other power of two, convert:
       uint32_t BitWidth = Op1C->getType()->getBitWidth();
       APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
-      ComputeMaskedBits(ICI->getOperand(0), KnownZero, KnownOne);
+      computeKnownBits(ICI->getOperand(0), KnownZero, KnownOne);
 
       APInt KnownZeroMask(~KnownZero);
       if (KnownZeroMask.isPowerOf2()) { // Exactly 1 possible 1?
@@ -598,8 +601,8 @@
 
       APInt KnownZeroLHS(BitWidth, 0), KnownOneLHS(BitWidth, 0);
       APInt KnownZeroRHS(BitWidth, 0), KnownOneRHS(BitWidth, 0);
-      ComputeMaskedBits(LHS, KnownZeroLHS, KnownOneLHS);
-      ComputeMaskedBits(RHS, KnownZeroRHS, KnownOneRHS);
+      computeKnownBits(LHS, KnownZeroLHS, KnownOneLHS);
+      computeKnownBits(RHS, KnownZeroRHS, KnownOneRHS);
 
       if (KnownZeroLHS == KnownZeroRHS && KnownOneLHS == KnownOneRHS) {
         APInt KnownBits = KnownZeroLHS | KnownOneLHS;
@@ -627,7 +630,7 @@
     }
   }
 
-  return 0;
+  return nullptr;
 }
 
 /// CanEvaluateZExtd - Determine if the specified value can be computed in the
@@ -758,7 +761,7 @@
   // If this zero extend is only used by a truncate, let the truncate be
   // eliminated before we try to optimize this zext.
   if (CI.hasOneUse() && isa<TruncInst>(CI.user_back()))
-    return 0;
+    return nullptr;
 
   // If one of the common conversion will work, do it.
   if (Instruction *Result = commonCastTransforms(CI))
@@ -883,7 +886,7 @@
     return BinaryOperator::CreateXor(New, ConstantInt::get(CI.getType(), 1));
   }
 
-  return 0;
+  return nullptr;
 }
 
 /// transformSExtICmp - Transform (sext icmp) to bitwise / integer operations
@@ -918,7 +921,7 @@
         ICI->isEquality() && (Op1C->isZero() || Op1C->getValue().isPowerOf2())){
       unsigned BitWidth = Op1C->getType()->getBitWidth();
       APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
-      ComputeMaskedBits(Op0, KnownZero, KnownOne);
+      computeKnownBits(Op0, KnownZero, KnownOne);
 
       APInt KnownZeroMask(~KnownZero);
       if (KnownZeroMask.isPowerOf2()) {
@@ -967,7 +970,7 @@
     }
   }
 
-  return 0;
+  return nullptr;
 }
 
 /// CanEvaluateSExtd - Return true if we can take the specified value
@@ -1039,7 +1042,7 @@
   // If this sign extend is only used by a truncate, let the truncate be
   // eliminated before we try to optimize this sext.
   if (CI.hasOneUse() && isa<TruncInst>(CI.user_back()))
-    return 0;
+    return nullptr;
 
   if (Instruction *I = commonCastTransforms(CI))
     return I;
@@ -1107,9 +1110,9 @@
   // into:
   //   %a = shl i32 %i, 30
   //   %d = ashr i32 %a, 30
-  Value *A = 0;
+  Value *A = nullptr;
   // TODO: Eventually this could be subsumed by EvaluateInDifferentType.
-  ConstantInt *BA = 0, *CA = 0;
+  ConstantInt *BA = nullptr, *CA = nullptr;
   if (match(Src, m_AShr(m_Shl(m_Trunc(m_Value(A)), m_ConstantInt(BA)),
                         m_ConstantInt(CA))) &&
       BA == CA && A->getType() == CI.getType()) {
@@ -1121,7 +1124,7 @@
     return BinaryOperator::CreateAShr(A, ShAmtV);
   }
 
-  return 0;
+  return nullptr;
 }
 
 
@@ -1133,7 +1136,7 @@
   (void)F.convert(Sem, APFloat::rmNearestTiesToEven, &losesInfo);
   if (!losesInfo)
     return ConstantFP::get(CFP->getContext(), F);
-  return 0;
+  return nullptr;
 }
 
 /// LookThroughFPExtensions - If this is an fp extension instruction, look
@@ -1345,7 +1348,7 @@
     }
   }
 
-  return 0;
+  return nullptr;
 }
 
 Instruction *InstCombiner::visitFPExt(CastInst &CI) {
@@ -1354,7 +1357,7 @@
 
 Instruction *InstCombiner::visitFPToUI(FPToUIInst &FI) {
   Instruction *OpI = dyn_cast<Instruction>(FI.getOperand(0));
-  if (OpI == 0)
+  if (!OpI)
     return commonCastTransforms(FI);
 
   // fptoui(uitofp(X)) --> X
@@ -1374,7 +1377,7 @@
 
 Instruction *InstCombiner::visitFPToSI(FPToSIInst &FI) {
   Instruction *OpI = dyn_cast<Instruction>(FI.getOperand(0));
-  if (OpI == 0)
+  if (!OpI)
     return commonCastTransforms(FI);
 
   // fptosi(sitofp(X)) --> X
@@ -1421,7 +1424,7 @@
   if (Instruction *I = commonCastTransforms(CI))
     return I;
 
-  return 0;
+  return nullptr;
 }
 
 /// @brief Implement the transforms for cast of pointer (bitcast/ptrtoint)
@@ -1520,7 +1523,7 @@
     // there yet.
     if (SrcTy->getElementType()->getPrimitiveSizeInBits() !=
         DestTy->getElementType()->getPrimitiveSizeInBits())
-      return 0;
+      return nullptr;
 
     SrcTy = VectorType::get(DestTy->getElementType(), SrcTy->getNumElements());
     InVal = IC.Builder->CreateBitCast(InVal, SrcTy);
@@ -1598,7 +1601,7 @@
       ElementIndex = Elements.size() - ElementIndex - 1;
 
     // Fail if multiple elements are inserted into this slot.
-    if (Elements[ElementIndex] != 0)
+    if (Elements[ElementIndex])
       return false;
 
     Elements[ElementIndex] = V;
@@ -1638,7 +1641,7 @@
   if (!V->hasOneUse()) return false;
 
   Instruction *I = dyn_cast<Instruction>(V);
-  if (I == 0) return false;
+  if (!I) return false;
   switch (I->getOpcode()) {
   default: return false; // Unhandled case.
   case Instruction::BitCast:
@@ -1659,7 +1662,7 @@
   case Instruction::Shl: {
     // Must be shifting by a constant that is a multiple of the element size.
     ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1));
-    if (CI == 0) return false;
+    if (!CI) return false;
     Shift += CI->getZExtValue();
     if (!isMultipleOfTypeSize(Shift, VecEltTy)) return false;
     return CollectInsertionElements(I->getOperand(0), Shift,
@@ -1687,7 +1690,7 @@
 static Value *OptimizeIntegerToVectorInsertions(BitCastInst &CI,
                                                 InstCombiner &IC) {
   // We need to know the target byte order to perform this optimization.
-  if (!IC.getDataLayout()) return 0;
+  if (!IC.getDataLayout()) return nullptr;
 
   VectorType *DestVecTy = cast<VectorType>(CI.getType());
   Value *IntInput = CI.getOperand(0);
@@ -1695,14 +1698,14 @@
   SmallVector<Value*, 8> Elements(DestVecTy->getNumElements());
   if (!CollectInsertionElements(IntInput, 0, Elements,
                                 DestVecTy->getElementType(), IC))
-    return 0;
+    return nullptr;
 
   // If we succeeded, we know that all of the element are specified by Elements
   // or are zero if Elements has a null entry.  Recast this as a set of
   // insertions.
   Value *Result = Constant::getNullValue(CI.getType());
   for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
-    if (Elements[i] == 0) continue;  // Unset element.
+    if (!Elements[i]) continue;  // Unset element.
 
     Result = IC.Builder->CreateInsertElement(Result, Elements[i],
                                              IC.Builder->getInt32(i));
@@ -1716,14 +1719,14 @@
 /// bitcast.  The various long double bitcasts can't get in here.
 static Instruction *OptimizeIntToFloatBitCast(BitCastInst &CI,InstCombiner &IC){
   // We need to know the target byte order to perform this optimization.
-  if (!IC.getDataLayout()) return 0;
+  if (!IC.getDataLayout()) return nullptr;
 
   Value *Src = CI.getOperand(0);
   Type *DestTy = CI.getType();
 
   // If this is a bitcast from int to float, check to see if the int is an
   // extraction from a vector.
-  Value *VecInput = 0;
+  Value *VecInput = nullptr;
   // bitcast(trunc(bitcast(somevector)))
   if (match(Src, m_Trunc(m_BitCast(m_Value(VecInput)))) &&
       isa<VectorType>(VecInput->getType())) {
@@ -1747,7 +1750,7 @@
   }
 
   // bitcast(trunc(lshr(bitcast(somevector), cst))
-  ConstantInt *ShAmt = 0;
+  ConstantInt *ShAmt = nullptr;
   if (match(Src, m_Trunc(m_LShr(m_BitCast(m_Value(VecInput)),
                                 m_ConstantInt(ShAmt)))) &&
       isa<VectorType>(VecInput->getType())) {
@@ -1769,7 +1772,7 @@
       return ExtractElementInst::Create(VecInput, IC.Builder->getInt32(Elt));
     }
   }
-  return 0;
+  return nullptr;
 }
 
 Instruction *InstCombiner::visitBitCast(BitCastInst &CI) {