X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FVMCore%2FConstants.cpp;h=2530b63d8a1335202c1197365051b6a177ae58c4;hb=71a494d6974f5105f008601a3e7c7474bf508139;hp=019a590f412d9c23675aec5a092080f64b6c3118;hpb=b447387726ff94ddb2a23408f39e22714c42f79b;p=oota-llvm.git

diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index 019a590f412..2530b63d8a1 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -40,6 +40,8 @@ using namespace llvm;
 //                              Constant Class
 //===----------------------------------------------------------------------===//
 
+void Constant::anchor() { }
+
 bool Constant::isNegativeZeroValue() const {
   // Floating point values have an explicit -0.0 value.
   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
@@ -49,11 +51,49 @@ bool Constant::isNegativeZeroValue() const {
   return isNullValue();
 }
 
+bool Constant::isNullValue() const {
+  // 0 is null.
+  if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
+    return CI->isZero();
+  
+  // +0.0 is null.
+  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
+    return CFP->isZero() && !CFP->isNegative();
+
+  // constant zero is zero for aggregates and cpnull is null for pointers.
+  return isa<ConstantAggregateZero>(this) || isa<ConstantPointerNull>(this);
+}
+
+bool Constant::isAllOnesValue() const {
+  // Check for -1 integers
+  if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
+    return CI->isMinusOne();
+
+  // Check for FP which are bitcasted from -1 integers
+  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
+    return CFP->getValueAPF().bitcastToAPInt().isAllOnesValue();
+
+  // Check for constant vectors which are splats of -1 values.
+  if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
+    if (Constant *Splat = CV->getSplatValue())
+      return Splat->isAllOnesValue();
+
+  // Check for constant vectors which are splats of -1 values.
+  if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
+    if (Constant *Splat = CV->getSplatValue())
+      return Splat->isAllOnesValue();
+
+  return false;
+}
+
 // Constructor to create a '0' constant of arbitrary type...
-Constant *Constant::getNullValue(const Type *Ty) {
+Constant *Constant::getNullValue(Type *Ty) {
   switch (Ty->getTypeID()) {
   case Type::IntegerTyID:
     return ConstantInt::get(Ty, 0);
+  case Type::HalfTyID:
+    return ConstantFP::get(Ty->getContext(),
+                           APFloat::getZero(APFloat::IEEEhalf));
   case Type::FloatTyID:
     return ConstantFP::get(Ty->getContext(),
                            APFloat::getZero(APFloat::IEEEsingle));
@@ -77,30 +117,30 @@ Constant *Constant::getNullValue(const Type *Ty) {
     return ConstantAggregateZero::get(Ty);
   default:
     // Function, Label, or Opaque type?
-    assert(!"Cannot create a null constant of that type!");
+    assert(0 && "Cannot create a null constant of that type!");
     return 0;
   }
 }
 
-Constant *Constant::getIntegerValue(const Type *Ty, const APInt &V) {
-  const Type *ScalarTy = Ty->getScalarType();
+Constant *Constant::getIntegerValue(Type *Ty, const APInt &V) {
+  Type *ScalarTy = Ty->getScalarType();
 
   // Create the base integer constant.
   Constant *C = ConstantInt::get(Ty->getContext(), V);
 
   // Convert an integer to a pointer, if necessary.
-  if (const PointerType *PTy = dyn_cast<PointerType>(ScalarTy))
+  if (PointerType *PTy = dyn_cast<PointerType>(ScalarTy))
     C = ConstantExpr::getIntToPtr(C, PTy);
 
   // Broadcast a scalar to a vector, if necessary.
-  if (const VectorType *VTy = dyn_cast<VectorType>(Ty))
-    C = ConstantVector::get(std::vector<Constant *>(VTy->getNumElements(), C));
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    C = ConstantVector::getSplat(VTy->getNumElements(), C);
 
   return C;
 }
 
-Constant *Constant::getAllOnesValue(const Type *Ty) {
-  if (const IntegerType *ITy = dyn_cast<IntegerType>(Ty))
+Constant *Constant::getAllOnesValue(Type *Ty) {
+  if (IntegerType *ITy = dyn_cast<IntegerType>(Ty))
     return ConstantInt::get(Ty->getContext(),
                             APInt::getAllOnesValue(ITy->getBitWidth()));
 
@@ -110,13 +150,44 @@ Constant *Constant::getAllOnesValue(const Type *Ty) {
     return ConstantFP::get(Ty->getContext(), FL);
   }
 
-  SmallVector<Constant*, 16> Elts;
-  const VectorType *VTy = cast<VectorType>(Ty);
-  Elts.resize(VTy->getNumElements(), getAllOnesValue(VTy->getElementType()));
-  assert(Elts[0] && "Not a vector integer type!");
-  return cast<ConstantVector>(ConstantVector::get(Elts));
+  VectorType *VTy = cast<VectorType>(Ty);
+  return ConstantVector::getSplat(VTy->getNumElements(),
+                                  getAllOnesValue(VTy->getElementType()));
 }
 
+/// getAggregateElement - For aggregates (struct/array/vector) return the
+/// constant that corresponds to the specified element if possible, or null if
+/// not.  This can return null if the element index is a ConstantExpr, or if
+/// 'this' is a constant expr.
+Constant *Constant::getAggregateElement(unsigned Elt) const {
+  if (const ConstantStruct *CS = dyn_cast<ConstantStruct>(this))
+    return Elt < CS->getNumOperands() ? CS->getOperand(Elt) : 0;
+  
+  if (const ConstantArray *CA = dyn_cast<ConstantArray>(this))
+    return Elt < CA->getNumOperands() ? CA->getOperand(Elt) : 0;
+  
+  if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
+    return Elt < CV->getNumOperands() ? CV->getOperand(Elt) : 0;
+  
+  if (const ConstantAggregateZero *CAZ =dyn_cast<ConstantAggregateZero>(this))
+    return CAZ->getElementValue(Elt);
+  
+  if (const UndefValue *UV = dyn_cast<UndefValue>(this))
+    return UV->getElementValue(Elt);
+  
+  if (const ConstantDataSequential *CDS =dyn_cast<ConstantDataSequential>(this))
+    return CDS->getElementAsConstant(Elt);
+  return 0;
+}
+
+Constant *Constant::getAggregateElement(Constant *Elt) const {
+  assert(isa<IntegerType>(Elt->getType()) && "Index must be an integer");
+  if (ConstantInt *CI = dyn_cast<ConstantInt>(Elt))
+    return getAggregateElement(CI->getZExtValue());
+  return 0;
+}
+
+
 void Constant::destroyConstantImpl() {
   // When a Constant is destroyed, there may be lingering
   // references to the constant by other constants in the constant pool.  These
@@ -135,8 +206,7 @@ void Constant::destroyConstantImpl() {
     }
 #endif
     assert(isa<Constant>(V) && "References remain to Constant being destroyed");
-    Constant *CV = cast<Constant>(V);
-    CV->destroyConstant();
+    cast<Constant>(V)->destroyConstant();
 
     // The constant should remove itself from our use list...
     assert((use_empty() || use_back() != V) && "Constant not removed!");
@@ -242,36 +312,6 @@ Constant::PossibleRelocationsTy Constant::getRelocationInfo() const {
   return Result;
 }
 
-
-/// getVectorElements - This method, which is only valid on constant of vector
-/// type, returns the elements of the vector in the specified smallvector.
-/// This handles breaking down a vector undef into undef elements, etc.  For
-/// constant exprs and other cases we can't handle, we return an empty vector.
-void Constant::getVectorElements(SmallVectorImpl<Constant*> &Elts) const {
-  assert(getType()->isVectorTy() && "Not a vector constant!");
-  
-  if (const ConstantVector *CV = dyn_cast<ConstantVector>(this)) {
-    for (unsigned i = 0, e = CV->getNumOperands(); i != e; ++i)
-      Elts.push_back(CV->getOperand(i));
-    return;
-  }
-  
-  const VectorType *VT = cast<VectorType>(getType());
-  if (isa<ConstantAggregateZero>(this)) {
-    Elts.assign(VT->getNumElements(), 
-                Constant::getNullValue(VT->getElementType()));
-    return;
-  }
-  
-  if (isa<UndefValue>(this)) {
-    Elts.assign(VT->getNumElements(), UndefValue::get(VT->getElementType()));
-    return;
-  }
-  
-  // Unknown type, must be constant expr etc.
-}
-
-
 /// removeDeadUsersOfConstant - If the specified constantexpr is dead, remove
 /// it.  This involves recursively eliminating any dead users of the
 /// constantexpr.
@@ -330,7 +370,9 @@ void Constant::removeDeadConstantUsers() const {
 //                                ConstantInt
 //===----------------------------------------------------------------------===//
 
-ConstantInt::ConstantInt(const IntegerType *Ty, const APInt& V)
+void ConstantInt::anchor() { }
+
+ConstantInt::ConstantInt(IntegerType *Ty, const APInt& V)
   : Constant(Ty, ConstantIntVal, 0, 0), Val(V) {
   assert(V.getBitWidth() == Ty->getBitWidth() && "Invalid constant for type");
 }
@@ -349,30 +391,28 @@ ConstantInt *ConstantInt::getFalse(LLVMContext &Context) {
   return pImpl->TheFalseVal;
 }
 
-Constant *ConstantInt::getTrue(const Type *Ty) {
-  const VectorType *VTy = dyn_cast<VectorType>(Ty);
+Constant *ConstantInt::getTrue(Type *Ty) {
+  VectorType *VTy = dyn_cast<VectorType>(Ty);
   if (!VTy) {
     assert(Ty->isIntegerTy(1) && "True must be i1 or vector of i1.");
     return ConstantInt::getTrue(Ty->getContext());
   }
   assert(VTy->getElementType()->isIntegerTy(1) &&
          "True must be vector of i1 or i1.");
-  SmallVector<Constant*, 16> Splat(VTy->getNumElements(),
-                                   ConstantInt::getTrue(Ty->getContext()));
-  return ConstantVector::get(Splat);
+  return ConstantVector::getSplat(VTy->getNumElements(),
+                                  ConstantInt::getTrue(Ty->getContext()));
 }
 
-Constant *ConstantInt::getFalse(const Type *Ty) {
-  const VectorType *VTy = dyn_cast<VectorType>(Ty);
+Constant *ConstantInt::getFalse(Type *Ty) {
+  VectorType *VTy = dyn_cast<VectorType>(Ty);
   if (!VTy) {
     assert(Ty->isIntegerTy(1) && "False must be i1 or vector of i1.");
     return ConstantInt::getFalse(Ty->getContext());
   }
   assert(VTy->getElementType()->isIntegerTy(1) &&
          "False must be vector of i1 or i1.");
-  SmallVector<Constant*, 16> Splat(VTy->getNumElements(),
-                                   ConstantInt::getFalse(Ty->getContext()));
-  return ConstantVector::get(Splat);
+  return ConstantVector::getSplat(VTy->getNumElements(),
+                                  ConstantInt::getFalse(Ty->getContext()));
 }
 
 
@@ -383,7 +423,7 @@ Constant *ConstantInt::getFalse(const Type *Ty) {
 // invariant which generates an assertion.
 ConstantInt *ConstantInt::get(LLVMContext &Context, const APInt &V) {
   // Get the corresponding integer type for the bit width of the value.
-  const IntegerType *ITy = IntegerType::get(Context, V.getBitWidth());
+  IntegerType *ITy = IntegerType::get(Context, V.getBitWidth());
   // get an existing value or the insertion position
   DenseMapAPIntKeyInfo::KeyTy Key(V, ITy);
   ConstantInt *&Slot = Context.pImpl->IntConstants[Key]; 
@@ -391,44 +431,42 @@ ConstantInt *ConstantInt::get(LLVMContext &Context, const APInt &V) {
   return Slot;
 }
 
-Constant *ConstantInt::get(const Type *Ty, uint64_t V, bool isSigned) {
+Constant *ConstantInt::get(Type *Ty, uint64_t V, bool isSigned) {
   Constant *C = get(cast<IntegerType>(Ty->getScalarType()), V, isSigned);
 
   // For vectors, broadcast the value.
-  if (const VectorType *VTy = dyn_cast<VectorType>(Ty))
-    return ConstantVector::get(SmallVector<Constant*,
-                                           16>(VTy->getNumElements(), C));
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getNumElements(), C);
 
   return C;
 }
 
-ConstantInt* ConstantInt::get(const IntegerType* Ty, uint64_t V, 
+ConstantInt* ConstantInt::get(IntegerType* Ty, uint64_t V, 
                               bool isSigned) {
   return get(Ty->getContext(), APInt(Ty->getBitWidth(), V, isSigned));
 }
 
-ConstantInt* ConstantInt::getSigned(const IntegerType* Ty, int64_t V) {
+ConstantInt* ConstantInt::getSigned(IntegerType* Ty, int64_t V) {
   return get(Ty, V, true);
 }
 
-Constant *ConstantInt::getSigned(const Type *Ty, int64_t V) {
+Constant *ConstantInt::getSigned(Type *Ty, int64_t V) {
   return get(Ty, V, true);
 }
 
-Constant *ConstantInt::get(const Type* Ty, const APInt& V) {
+Constant *ConstantInt::get(Type* Ty, const APInt& V) {
   ConstantInt *C = get(Ty->getContext(), V);
   assert(C->getType() == Ty->getScalarType() &&
          "ConstantInt type doesn't match the type implied by its value!");
 
   // For vectors, broadcast the value.
-  if (const VectorType *VTy = dyn_cast<VectorType>(Ty))
-    return ConstantVector::get(
-      SmallVector<Constant *, 16>(VTy->getNumElements(), C));
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getNumElements(), C);
 
   return C;
 }
 
-ConstantInt* ConstantInt::get(const IntegerType* Ty, StringRef Str,
+ConstantInt* ConstantInt::get(IntegerType* Ty, StringRef Str,
                               uint8_t radix) {
   return get(Ty->getContext(), APInt(Ty->getBitWidth(), Str, radix));
 }
@@ -437,7 +475,9 @@ ConstantInt* ConstantInt::get(const IntegerType* Ty, StringRef Str,
 //                                ConstantFP
 //===----------------------------------------------------------------------===//
 
-static const fltSemantics *TypeToFloatSemantics(const Type *Ty) {
+static const fltSemantics *TypeToFloatSemantics(Type *Ty) {
+  if (Ty->isHalfTy())
+    return &APFloat::IEEEhalf;
   if (Ty->isFloatTy())
     return &APFloat::IEEEsingle;
   if (Ty->isDoubleTy())
@@ -451,10 +491,12 @@ static const fltSemantics *TypeToFloatSemantics(const Type *Ty) {
   return &APFloat::PPCDoubleDouble;
 }
 
+void ConstantFP::anchor() { }
+
 /// get() - This returns a constant fp for the specified value in the
 /// specified type.  This should only be used for simple constant values like
 /// 2.0/1.0 etc, that are known-valid both as double and as the target format.
-Constant *ConstantFP::get(const Type* Ty, double V) {
+Constant *ConstantFP::get(Type* Ty, double V) {
   LLVMContext &Context = Ty->getContext();
   
   APFloat FV(V);
@@ -464,47 +506,43 @@ Constant *ConstantFP::get(const Type* Ty, double V) {
   Constant *C = get(Context, FV);
 
   // For vectors, broadcast the value.
-  if (const VectorType *VTy = dyn_cast<VectorType>(Ty))
-    return ConstantVector::get(
-      SmallVector<Constant *, 16>(VTy->getNumElements(), C));
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getNumElements(), C);
 
   return C;
 }
 
 
-Constant *ConstantFP::get(const Type* Ty, StringRef Str) {
+Constant *ConstantFP::get(Type* Ty, StringRef Str) {
   LLVMContext &Context = Ty->getContext();
 
   APFloat FV(*TypeToFloatSemantics(Ty->getScalarType()), Str);
   Constant *C = get(Context, FV);
 
   // For vectors, broadcast the value.
-  if (const VectorType *VTy = dyn_cast<VectorType>(Ty))
-    return ConstantVector::get(
-      SmallVector<Constant *, 16>(VTy->getNumElements(), C));
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getNumElements(), C);
 
   return C; 
 }
 
 
-ConstantFP* ConstantFP::getNegativeZero(const Type* Ty) {
+ConstantFP *ConstantFP::getNegativeZero(Type *Ty) {
   LLVMContext &Context = Ty->getContext();
-  APFloat apf = cast <ConstantFP>(Constant::getNullValue(Ty))->getValueAPF();
+  APFloat apf = cast<ConstantFP>(Constant::getNullValue(Ty))->getValueAPF();
   apf.changeSign();
   return get(Context, apf);
 }
 
 
-Constant *ConstantFP::getZeroValueForNegation(const Type* Ty) {
-  if (const VectorType *PTy = dyn_cast<VectorType>(Ty))
-    if (PTy->getElementType()->isFloatingPointTy()) {
-      SmallVector<Constant*, 16> zeros(PTy->getNumElements(),
-                           getNegativeZero(PTy->getElementType()));
-      return ConstantVector::get(zeros);
-    }
-
-  if (Ty->isFloatingPointTy()) 
-    return getNegativeZero(Ty);
+Constant *ConstantFP::getZeroValueForNegation(Type *Ty) {
+  Type *ScalarTy = Ty->getScalarType();
+  if (ScalarTy->isFloatingPointTy()) {
+    Constant *C = getNegativeZero(ScalarTy);
+    if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+      return ConstantVector::getSplat(VTy->getNumElements(), C);
+    return C;
+  }
 
   return Constant::getNullValue(Ty);
 }
@@ -519,8 +557,10 @@ ConstantFP* ConstantFP::get(LLVMContext &Context, const APFloat& V) {
   ConstantFP *&Slot = pImpl->FPConstants[Key];
     
   if (!Slot) {
-    const Type *Ty;
-    if (&V.getSemantics() == &APFloat::IEEEsingle)
+    Type *Ty;
+    if (&V.getSemantics() == &APFloat::IEEEhalf)
+      Ty = Type::getHalfTy(Context);
+    else if (&V.getSemantics() == &APFloat::IEEEsingle)
       Ty = Type::getFloatTy(Context);
     else if (&V.getSemantics() == &APFloat::IEEEdouble)
       Ty = Type::getDoubleTy(Context);
@@ -539,66 +579,134 @@ ConstantFP* ConstantFP::get(LLVMContext &Context, const APFloat& V) {
   return Slot;
 }
 
-ConstantFP *ConstantFP::getInfinity(const Type *Ty, bool Negative) {
+ConstantFP *ConstantFP::getInfinity(Type *Ty, bool Negative) {
   const fltSemantics &Semantics = *TypeToFloatSemantics(Ty);
   return ConstantFP::get(Ty->getContext(),
                          APFloat::getInf(Semantics, Negative));
 }
 
-ConstantFP::ConstantFP(const Type *Ty, const APFloat& V)
+ConstantFP::ConstantFP(Type *Ty, const APFloat& V)
   : Constant(Ty, ConstantFPVal, 0, 0), Val(V) {
   assert(&V.getSemantics() == TypeToFloatSemantics(Ty) &&
          "FP type Mismatch");
 }
 
-bool ConstantFP::isNullValue() const {
-  return Val.isZero() && !Val.isNegative();
+bool ConstantFP::isExactlyValue(const APFloat &V) const {
+  return Val.bitwiseIsEqual(V);
 }
 
-bool ConstantFP::isExactlyValue(const APFloat& V) const {
-  return Val.bitwiseIsEqual(V);
+//===----------------------------------------------------------------------===//
+//                   ConstantAggregateZero Implementation
+//===----------------------------------------------------------------------===//
+
+/// getSequentialElement - If this CAZ has array or vector type, return a zero
+/// with the right element type.
+Constant *ConstantAggregateZero::getSequentialElement() const {
+  return Constant::getNullValue(getType()->getSequentialElementType());
+}
+
+/// getStructElement - If this CAZ has struct type, return a zero with the
+/// right element type for the specified element.
+Constant *ConstantAggregateZero::getStructElement(unsigned Elt) const {
+  return Constant::getNullValue(getType()->getStructElementType(Elt));
+}
+
+/// getElementValue - Return a zero of the right value for the specified GEP
+/// index if we can, otherwise return null (e.g. if C is a ConstantExpr).
+Constant *ConstantAggregateZero::getElementValue(Constant *C) const {
+  if (isa<SequentialType>(getType()))
+    return getSequentialElement();
+  return getStructElement(cast<ConstantInt>(C)->getZExtValue());
+}
+
+/// getElementValue - Return a zero of the right value for the specified GEP
+/// index.
+Constant *ConstantAggregateZero::getElementValue(unsigned Idx) const {
+  if (isa<SequentialType>(getType()))
+    return getSequentialElement();
+  return getStructElement(Idx);
+}
+
+
+//===----------------------------------------------------------------------===//
+//                         UndefValue Implementation
+//===----------------------------------------------------------------------===//
+
+/// getSequentialElement - If this undef has array or vector type, return an
+/// undef with the right element type.
+UndefValue *UndefValue::getSequentialElement() const {
+  return UndefValue::get(getType()->getSequentialElementType());
+}
+
+/// getStructElement - If this undef has struct type, return a zero with the
+/// right element type for the specified element.
+UndefValue *UndefValue::getStructElement(unsigned Elt) const {
+  return UndefValue::get(getType()->getStructElementType(Elt));
+}
+
+/// getElementValue - Return an undef of the right value for the specified GEP
+/// index if we can, otherwise return null (e.g. if C is a ConstantExpr).
+UndefValue *UndefValue::getElementValue(Constant *C) const {
+  if (isa<SequentialType>(getType()))
+    return getSequentialElement();
+  return getStructElement(cast<ConstantInt>(C)->getZExtValue());
 }
 
+/// getElementValue - Return an undef of the right value for the specified GEP
+/// index.
+UndefValue *UndefValue::getElementValue(unsigned Idx) const {
+  if (isa<SequentialType>(getType()))
+    return getSequentialElement();
+  return getStructElement(Idx);
+}
+
+
+
 //===----------------------------------------------------------------------===//
 //                            ConstantXXX Classes
 //===----------------------------------------------------------------------===//
 
 
-ConstantArray::ConstantArray(const ArrayType *T,
-                             const std::vector<Constant*> &V)
+ConstantArray::ConstantArray(ArrayType *T, ArrayRef<Constant *> V)
   : Constant(T, ConstantArrayVal,
              OperandTraits<ConstantArray>::op_end(this) - V.size(),
              V.size()) {
   assert(V.size() == T->getNumElements() &&
          "Invalid initializer vector for constant array");
-  Use *OL = OperandList;
-  for (std::vector<Constant*>::const_iterator I = V.begin(), E = V.end();
-       I != E; ++I, ++OL) {
-    Constant *C = *I;
-    assert(C->getType() == T->getElementType() &&
+  for (unsigned i = 0, e = V.size(); i != e; ++i)
+    assert(V[i]->getType() == T->getElementType() &&
            "Initializer for array element doesn't match array element type!");
-    *OL = C;
-  }
+  std::copy(V.begin(), V.end(), op_begin());
 }
 
-Constant *ConstantArray::get(const ArrayType *Ty, ArrayRef<Constant*> V) {
+Constant *ConstantArray::get(ArrayType *Ty, ArrayRef<Constant*> V) {
   for (unsigned i = 0, e = V.size(); i != e; ++i) {
     assert(V[i]->getType() == Ty->getElementType() &&
            "Wrong type in array element initializer");
   }
   LLVMContextImpl *pImpl = Ty->getContext().pImpl;
   // If this is an all-zero array, return a ConstantAggregateZero object
+  bool isAllZero = true;
+  bool isUndef = false;
   if (!V.empty()) {
     Constant *C = V[0];
-    if (!C->isNullValue())
-      return pImpl->ArrayConstants.getOrCreate(Ty, V);
-    
-    for (unsigned i = 1, e = V.size(); i != e; ++i)
-      if (V[i] != C)
-        return pImpl->ArrayConstants.getOrCreate(Ty, V);
+    isAllZero = C->isNullValue();
+    isUndef = isa<UndefValue>(C);
+
+    if (isAllZero || isUndef)
+      for (unsigned i = 1, e = V.size(); i != e; ++i)
+        if (V[i] != C) {
+          isAllZero = false;
+          isUndef = false;
+          break;
+        }
   }
-  
-  return ConstantAggregateZero::get(Ty);
+
+  if (isAllZero)
+    return ConstantAggregateZero::get(Ty);
+  if (isUndef)
+    return UndefValue::get(Ty);
+  return pImpl->ArrayConstants.getOrCreate(Ty, V);
 }
 
 /// ConstantArray::get(const string&) - Return an array that is initialized to
@@ -615,9 +723,8 @@ Constant *ConstantArray::get(LLVMContext &Context, StringRef Str,
     ElementVals.push_back(ConstantInt::get(Type::getInt8Ty(Context), Str[i]));
 
   // Add a null terminator to the string...
-  if (AddNull) {
+  if (AddNull)
     ElementVals.push_back(ConstantInt::get(Type::getInt8Ty(Context), 0));
-  }
 
   ArrayType *ATy = ArrayType::get(Type::getInt8Ty(Context), ElementVals.size());
   return get(ATy, ElementVals);
@@ -644,36 +751,48 @@ StructType *ConstantStruct::getTypeForElements(ArrayRef<Constant*> V,
 }
 
 
-ConstantStruct::ConstantStruct(const StructType *T,
-                               const std::vector<Constant*> &V)
+ConstantStruct::ConstantStruct(StructType *T, ArrayRef<Constant *> V)
   : Constant(T, ConstantStructVal,
              OperandTraits<ConstantStruct>::op_end(this) - V.size(),
              V.size()) {
-  assert((T->isOpaque() || V.size() == T->getNumElements()) &&
+  assert(V.size() == T->getNumElements() &&
          "Invalid initializer vector for constant structure");
-  Use *OL = OperandList;
-  for (std::vector<Constant*>::const_iterator I = V.begin(), E = V.end();
-       I != E; ++I, ++OL) {
-    Constant *C = *I;
-    assert((T->isOpaque() || C->getType() == T->getElementType(I-V.begin())) &&
+  for (unsigned i = 0, e = V.size(); i != e; ++i)
+    assert((T->isOpaque() || V[i]->getType() == T->getElementType(i)) &&
            "Initializer for struct element doesn't match struct element type!");
-    *OL = C;
-  }
+  std::copy(V.begin(), V.end(), op_begin());
 }
 
 // ConstantStruct accessors.
-Constant *ConstantStruct::get(const StructType *ST, ArrayRef<Constant*> V) {
-  // Create a ConstantAggregateZero value if all elements are zeros.
-  for (unsigned i = 0, e = V.size(); i != e; ++i)
-    if (!V[i]->isNullValue())
-      return ST->getContext().pImpl->StructConstants.getOrCreate(ST, V);
-
+Constant *ConstantStruct::get(StructType *ST, ArrayRef<Constant*> V) {
   assert((ST->isOpaque() || ST->getNumElements() == V.size()) &&
          "Incorrect # elements specified to ConstantStruct::get");
-  return ConstantAggregateZero::get(ST);
+
+  // Create a ConstantAggregateZero value if all elements are zeros.
+  bool isZero = true;
+  bool isUndef = false;
+  
+  if (!V.empty()) {
+    isUndef = isa<UndefValue>(V[0]);
+    isZero = V[0]->isNullValue();
+    if (isUndef || isZero) {
+      for (unsigned i = 0, e = V.size(); i != e; ++i) {
+        if (!V[i]->isNullValue())
+          isZero = false;
+        if (!isa<UndefValue>(V[i]))
+          isUndef = false;
+      }
+    }
+  }  
+  if (isZero)
+    return ConstantAggregateZero::get(ST);
+  if (isUndef)
+    return UndefValue::get(ST);
+    
+  return ST->getContext().pImpl->StructConstants.getOrCreate(ST, V);
 }
 
-Constant* ConstantStruct::get(const StructType *T, ...) {
+Constant *ConstantStruct::get(StructType *T, ...) {
   va_list ap;
   SmallVector<Constant*, 8> Values;
   va_start(ap, T);
@@ -683,25 +802,20 @@ Constant* ConstantStruct::get(const StructType *T, ...) {
   return get(T, Values);
 }
 
-ConstantVector::ConstantVector(const VectorType *T,
-                               const std::vector<Constant*> &V)
+ConstantVector::ConstantVector(VectorType *T, ArrayRef<Constant *> V)
   : Constant(T, ConstantVectorVal,
              OperandTraits<ConstantVector>::op_end(this) - V.size(),
              V.size()) {
-  Use *OL = OperandList;
-  for (std::vector<Constant*>::const_iterator I = V.begin(), E = V.end();
-       I != E; ++I, ++OL) {
-    Constant *C = *I;
-    assert(C->getType() == T->getElementType() &&
+  for (size_t i = 0, e = V.size(); i != e; i++)
+    assert(V[i]->getType() == T->getElementType() &&
            "Initializer for vector element doesn't match vector element type!");
-    *OL = C;
-  }
+  std::copy(V.begin(), V.end(), op_begin());
 }
 
 // ConstantVector accessors.
 Constant *ConstantVector::get(ArrayRef<Constant*> V) {
   assert(!V.empty() && "Vectors can't be empty");
-  const VectorType *T = VectorType::get(V.front()->getType(), V.size());
+  VectorType *T = VectorType::get(V.front()->getType(), V.size());
   LLVMContextImpl *pImpl = T->getContext().pImpl;
 
   // If this is an all-undef or all-zero vector, return a
@@ -726,6 +840,12 @@ Constant *ConstantVector::get(ArrayRef<Constant*> V) {
   return pImpl->VectorConstants.getOrCreate(T, V);
 }
 
+Constant *ConstantVector::getSplat(unsigned NumElts, Constant *V) {
+  SmallVector<Constant*, 32> Elts(NumElts, V);
+  return get(Elts);
+}
+
+
 // Utility function for determining if a ConstantExpr is a CastOp or not. This
 // can't be inline because we don't want to #include Instruction.h into
 // Constant.h
@@ -752,7 +872,7 @@ bool ConstantExpr::isGEPWithNoNotionalOverIndexing() const {
   for (; GEPI != E; ++GEPI, ++OI) {
     ConstantInt *CI = dyn_cast<ConstantInt>(*OI);
     if (!CI) return false;
-    if (const ArrayType *ATy = dyn_cast<ArrayType>(*GEPI))
+    if (ArrayType *ATy = dyn_cast<ArrayType>(*GEPI))
       if (CI->getValue().getActiveBits() > 64 ||
           CI->getZExtValue() >= ATy->getNumElements())
         return false;
@@ -776,8 +896,7 @@ ArrayRef<unsigned> ConstantExpr::getIndices() const {
 }
 
 unsigned ConstantExpr::getPredicate() const {
-  assert(getOpcode() == Instruction::FCmp || 
-         getOpcode() == Instruction::ICmp);
+  assert(isCompare());
   return ((const CompareConstantExpr*)this)->predicate;
 }
 
@@ -831,13 +950,13 @@ ConstantExpr::getWithOperandReplaced(unsigned OpNo, Constant *Op) const {
     for (unsigned i = 1, e = getNumOperands(); i != e; ++i)
       Ops[i-1] = getOperand(i);
     if (OpNo == 0)
-      return cast<GEPOperator>(this)->isInBounds() ?
-        ConstantExpr::getInBoundsGetElementPtr(Op, &Ops[0], Ops.size()) :
-        ConstantExpr::getGetElementPtr(Op, &Ops[0], Ops.size());
+      return
+        ConstantExpr::getGetElementPtr(Op, Ops,
+                                       cast<GEPOperator>(this)->isInBounds());
     Ops[OpNo-1] = Op;
-    return cast<GEPOperator>(this)->isInBounds() ?
-      ConstantExpr::getInBoundsGetElementPtr(getOperand(0), &Ops[0],Ops.size()):
-      ConstantExpr::getGetElementPtr(getOperand(0), &Ops[0], Ops.size());
+    return
+      ConstantExpr::getGetElementPtr(getOperand(0), Ops,
+                                     cast<GEPOperator>(this)->isInBounds());
   }
   default:
     assert(getNumOperands() == 2 && "Must be binary operator?");
@@ -851,7 +970,7 @@ ConstantExpr::getWithOperandReplaced(unsigned OpNo, Constant *Op) const {
 /// operands replaced with the specified values.  The specified array must
 /// have the same number of operands as our current one.
 Constant *ConstantExpr::
-getWithOperands(ArrayRef<Constant*> Ops, const Type *Ty) const {
+getWithOperands(ArrayRef<Constant*> Ops, Type *Ty) const {
   assert(Ops.size() == getNumOperands() && "Operand count mismatch!");
   bool AnyChange = Ty != getType();
   for (unsigned i = 0; i != Ops.size(); ++i)
@@ -883,9 +1002,9 @@ getWithOperands(ArrayRef<Constant*> Ops, const Type *Ty) const {
   case Instruction::ShuffleVector:
     return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]);
   case Instruction::GetElementPtr:
-    return cast<GEPOperator>(this)->isInBounds() ?
-      ConstantExpr::getInBoundsGetElementPtr(Ops[0], &Ops[1], Ops.size()-1) :
-      ConstantExpr::getGetElementPtr(Ops[0], &Ops[1], Ops.size()-1);
+    return
+      ConstantExpr::getGetElementPtr(Ops[0], Ops.slice(1),
+                                     cast<GEPOperator>(this)->isInBounds());
   case Instruction::ICmp:
   case Instruction::FCmp:
     return ConstantExpr::getCompare(getPredicate(), Ops[0], Ops[1]);
@@ -899,9 +1018,9 @@ getWithOperands(ArrayRef<Constant*> Ops, const Type *Ty) const {
 //===----------------------------------------------------------------------===//
 //                      isValueValidForType implementations
 
-bool ConstantInt::isValueValidForType(const Type *Ty, uint64_t Val) {
-  unsigned NumBits = cast<IntegerType>(Ty)->getBitWidth(); // assert okay
-  if (Ty == Type::getInt1Ty(Ty->getContext()))
+bool ConstantInt::isValueValidForType(Type *Ty, uint64_t Val) {
+  unsigned NumBits = Ty->getIntegerBitWidth(); // assert okay
+  if (Ty->isIntegerTy(1))
     return Val == 0 || Val == 1;
   if (NumBits >= 64)
     return true; // always true, has to fit in largest type
@@ -909,9 +1028,9 @@ bool ConstantInt::isValueValidForType(const Type *Ty, uint64_t Val) {
   return Val <= Max;
 }
 
-bool ConstantInt::isValueValidForType(const Type *Ty, int64_t Val) {
-  unsigned NumBits = cast<IntegerType>(Ty)->getBitWidth(); // assert okay
-  if (Ty == Type::getInt1Ty(Ty->getContext()))
+bool ConstantInt::isValueValidForType(Type *Ty, int64_t Val) {
+  unsigned NumBits = Ty->getIntegerBitWidth();
+  if (Ty->isIntegerTy(1))
     return Val == 0 || Val == 1 || Val == -1;
   if (NumBits >= 64)
     return true; // always true, has to fit in largest type
@@ -920,7 +1039,7 @@ bool ConstantInt::isValueValidForType(const Type *Ty, int64_t Val) {
   return (Val >= Min && Val <= Max);
 }
 
-bool ConstantFP::isValueValidForType(const Type *Ty, const APFloat& Val) {
+bool ConstantFP::isValueValidForType(Type *Ty, const APFloat& Val) {
   // convert modifies in place, so make a copy.
   APFloat Val2 = APFloat(Val);
   bool losesInfo;
@@ -929,6 +1048,12 @@ bool ConstantFP::isValueValidForType(const Type *Ty, const APFloat& Val) {
     return false;         // These can't be represented as floating point!
 
   // FIXME rounding mode needs to be more flexible
+  case Type::HalfTyID: {
+    if (&Val2.getSemantics() == &APFloat::IEEEhalf)
+      return true;
+    Val2.convert(APFloat::IEEEhalf, APFloat::rmNearestTiesToEven, &losesInfo);
+    return !losesInfo;
+  }
   case Type::FloatTyID: {
     if (&Val2.getSemantics() == &APFloat::IEEEsingle)
       return true;
@@ -936,42 +1061,50 @@ bool ConstantFP::isValueValidForType(const Type *Ty, const APFloat& Val) {
     return !losesInfo;
   }
   case Type::DoubleTyID: {
-    if (&Val2.getSemantics() == &APFloat::IEEEsingle ||
+    if (&Val2.getSemantics() == &APFloat::IEEEhalf ||
+        &Val2.getSemantics() == &APFloat::IEEEsingle ||
         &Val2.getSemantics() == &APFloat::IEEEdouble)
       return true;
     Val2.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &losesInfo);
     return !losesInfo;
   }
   case Type::X86_FP80TyID:
-    return &Val2.getSemantics() == &APFloat::IEEEsingle || 
+    return &Val2.getSemantics() == &APFloat::IEEEhalf ||
+           &Val2.getSemantics() == &APFloat::IEEEsingle || 
            &Val2.getSemantics() == &APFloat::IEEEdouble ||
            &Val2.getSemantics() == &APFloat::x87DoubleExtended;
   case Type::FP128TyID:
-    return &Val2.getSemantics() == &APFloat::IEEEsingle || 
+    return &Val2.getSemantics() == &APFloat::IEEEhalf ||
+           &Val2.getSemantics() == &APFloat::IEEEsingle || 
            &Val2.getSemantics() == &APFloat::IEEEdouble ||
            &Val2.getSemantics() == &APFloat::IEEEquad;
   case Type::PPC_FP128TyID:
-    return &Val2.getSemantics() == &APFloat::IEEEsingle || 
+    return &Val2.getSemantics() == &APFloat::IEEEhalf ||
+           &Val2.getSemantics() == &APFloat::IEEEsingle || 
            &Val2.getSemantics() == &APFloat::IEEEdouble ||
            &Val2.getSemantics() == &APFloat::PPCDoubleDouble;
   }
 }
 
+
 //===----------------------------------------------------------------------===//
 //                      Factory Function Implementation
 
-ConstantAggregateZero* ConstantAggregateZero::get(const Type* Ty) {
+ConstantAggregateZero *ConstantAggregateZero::get(Type *Ty) {
   assert((Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy()) &&
          "Cannot create an aggregate zero of non-aggregate type!");
   
-  LLVMContextImpl *pImpl = Ty->getContext().pImpl;
-  return pImpl->AggZeroConstants.getOrCreate(Ty, 0);
+  ConstantAggregateZero *&Entry = Ty->getContext().pImpl->CAZConstants[Ty];
+  if (Entry == 0)
+    Entry = new ConstantAggregateZero(Ty);
+  
+  return Entry;
 }
 
-/// destroyConstant - Remove the constant from the constant table...
+/// destroyConstant - Remove the constant from the constant table.
 ///
 void ConstantAggregateZero::destroyConstant() {
-  getType()->getContext().pImpl->AggZeroConstants.remove(this);
+  getContext().pImpl->CAZConstants.erase(getType());
   destroyConstantImpl();
 }
 
@@ -1019,8 +1152,7 @@ bool ConstantArray::isCString() const {
 
 
 /// convertToString - Helper function for getAsString() and getAsCString().
-static std::string convertToString(const User *U, unsigned len)
-{
+static std::string convertToString(const User *U, unsigned len) {
   std::string Result;
   Result.reserve(len);
   for (unsigned i = 0; i != len; ++i)
@@ -1050,10 +1182,6 @@ std::string ConstantArray::getAsCString() const {
 //---- ConstantStruct::get() implementation...
 //
 
-namespace llvm {
-
-}
-
 // destroyConstant - Remove the constant from the constant table...
 //
 void ConstantStruct::destroyConstant() {
@@ -1068,22 +1196,6 @@ void ConstantVector::destroyConstant() {
   destroyConstantImpl();
 }
 
-/// This function will return true iff every element in this vector constant
-/// is set to all ones.
-/// @returns true iff this constant's emements are all set to all ones.
-/// @brief Determine if the value is all ones.
-bool ConstantVector::isAllOnesValue() const {
-  // Check out first element.
-  const Constant *Elt = getOperand(0);
-  const ConstantInt *CI = dyn_cast<ConstantInt>(Elt);
-  if (!CI || !CI->isAllOnesValue()) return false;
-  // Then make sure all remaining elements point to the same value.
-  for (unsigned I = 1, E = getNumOperands(); I < E; ++I) {
-    if (getOperand(I) != Elt) return false;
-  }
-  return true;
-}
-
 /// getSplatValue - If this is a splat constant, where all of the
 /// elements have the same value, return that value. Otherwise return null.
 Constant *ConstantVector::getSplatValue() const {
@@ -1091,21 +1203,27 @@ Constant *ConstantVector::getSplatValue() const {
   Constant *Elt = getOperand(0);
   // Then make sure all remaining elements point to the same value.
   for (unsigned I = 1, E = getNumOperands(); I < E; ++I)
-    if (getOperand(I) != Elt) return 0;
+    if (getOperand(I) != Elt)
+      return 0;
   return Elt;
 }
 
 //---- ConstantPointerNull::get() implementation.
 //
 
-ConstantPointerNull *ConstantPointerNull::get(const PointerType *Ty) {
-  return Ty->getContext().pImpl->NullPtrConstants.getOrCreate(Ty, 0);
+ConstantPointerNull *ConstantPointerNull::get(PointerType *Ty) {
+  ConstantPointerNull *&Entry = Ty->getContext().pImpl->CPNConstants[Ty];
+  if (Entry == 0)
+    Entry = new ConstantPointerNull(Ty);
+  
+  return Entry;
 }
 
 // destroyConstant - Remove the constant from the constant table...
 //
 void ConstantPointerNull::destroyConstant() {
-  getType()->getContext().pImpl->NullPtrConstants.remove(this);
+  getContext().pImpl->CPNConstants.erase(getType());
+  // Free the constant and any dangling references to it.
   destroyConstantImpl();
 }
 
@@ -1113,14 +1231,19 @@ void ConstantPointerNull::destroyConstant() {
 //---- UndefValue::get() implementation.
 //
 
-UndefValue *UndefValue::get(const Type *Ty) {
-  return Ty->getContext().pImpl->UndefValueConstants.getOrCreate(Ty, 0);
+UndefValue *UndefValue::get(Type *Ty) {
+  UndefValue *&Entry = Ty->getContext().pImpl->UVConstants[Ty];
+  if (Entry == 0)
+    Entry = new UndefValue(Ty);
+  
+  return Entry;
 }
 
 // destroyConstant - Remove the constant from the constant table.
 //
 void UndefValue::destroyConstant() {
-  getType()->getContext().pImpl->UndefValueConstants.remove(this);
+  // Free the constant and any dangling references to it.
+  getContext().pImpl->UVConstants.erase(getType());
   destroyConstantImpl();
 }
 
@@ -1193,7 +1316,7 @@ void BlockAddress::replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U) {
   assert(NewBA != this && "I didn't contain From!");
   
   // Everyone using this now uses the replacement.
-  uncheckedReplaceAllUsesWith(NewBA);
+  replaceAllUsesWith(NewBA);
   
   destroyConstant();
 }
@@ -1204,7 +1327,7 @@ void BlockAddress::replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U) {
 /// This is a utility function to handle folding of casts and lookup of the
 /// cast in the ExprConstants map. It is used by the various get* methods below.
 static inline Constant *getFoldedCast(
-  Instruction::CastOps opc, Constant *C, const Type *Ty) {
+  Instruction::CastOps opc, Constant *C, Type *Ty) {
   assert(Ty->isFirstClassType() && "Cannot cast to an aggregate type!");
   // Fold a few common cases
   if (Constant *FC = ConstantFoldCastInstruction(opc, C, Ty))
@@ -1219,7 +1342,7 @@ static inline Constant *getFoldedCast(
   return pImpl->ExprConstants.getOrCreate(Ty, Key);
 }
  
-Constant *ConstantExpr::getCast(unsigned oc, Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getCast(unsigned oc, Constant *C, Type *Ty) {
   Instruction::CastOps opc = Instruction::CastOps(oc);
   assert(Instruction::isCast(opc) && "opcode out of range");
   assert(C && Ty && "Null arguments to getCast");
@@ -1228,7 +1351,6 @@ Constant *ConstantExpr::getCast(unsigned oc, Constant *C, const Type *Ty) {
   switch (opc) {
   default:
     llvm_unreachable("Invalid cast opcode");
-    break;
   case Instruction::Trunc:    return getTrunc(C, Ty);
   case Instruction::ZExt:     return getZExt(C, Ty);
   case Instruction::SExt:     return getSExt(C, Ty);
@@ -1242,28 +1364,27 @@ Constant *ConstantExpr::getCast(unsigned oc, Constant *C, const Type *Ty) {
   case Instruction::IntToPtr: return getIntToPtr(C, Ty);
   case Instruction::BitCast:  return getBitCast(C, Ty);
   }
-  return 0;
 } 
 
-Constant *ConstantExpr::getZExtOrBitCast(Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getZExtOrBitCast(Constant *C, Type *Ty) {
   if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
     return getBitCast(C, Ty);
   return getZExt(C, Ty);
 }
 
-Constant *ConstantExpr::getSExtOrBitCast(Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getSExtOrBitCast(Constant *C, Type *Ty) {
   if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
     return getBitCast(C, Ty);
   return getSExt(C, Ty);
 }
 
-Constant *ConstantExpr::getTruncOrBitCast(Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getTruncOrBitCast(Constant *C, Type *Ty) {
   if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
     return getBitCast(C, Ty);
   return getTrunc(C, Ty);
 }
 
-Constant *ConstantExpr::getPointerCast(Constant *S, const Type *Ty) {
+Constant *ConstantExpr::getPointerCast(Constant *S, Type *Ty) {
   assert(S->getType()->isPointerTy() && "Invalid cast");
   assert((Ty->isIntegerTy() || Ty->isPointerTy()) && "Invalid cast");
 
@@ -1272,7 +1393,7 @@ Constant *ConstantExpr::getPointerCast(Constant *S, const Type *Ty) {
   return getBitCast(S, Ty);
 }
 
-Constant *ConstantExpr::getIntegerCast(Constant *C, const Type *Ty, 
+Constant *ConstantExpr::getIntegerCast(Constant *C, Type *Ty, 
                                        bool isSigned) {
   assert(C->getType()->isIntOrIntVectorTy() &&
          Ty->isIntOrIntVectorTy() && "Invalid cast");
@@ -1285,7 +1406,7 @@ Constant *ConstantExpr::getIntegerCast(Constant *C, const Type *Ty,
   return getCast(opcode, C, Ty);
 }
 
-Constant *ConstantExpr::getFPCast(Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getFPCast(Constant *C, Type *Ty) {
   assert(C->getType()->isFPOrFPVectorTy() && Ty->isFPOrFPVectorTy() &&
          "Invalid cast");
   unsigned SrcBits = C->getType()->getScalarSizeInBits();
@@ -1297,7 +1418,7 @@ Constant *ConstantExpr::getFPCast(Constant *C, const Type *Ty) {
   return getCast(opcode, C, Ty);
 }
 
-Constant *ConstantExpr::getTrunc(Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getTrunc(Constant *C, Type *Ty) {
 #ifndef NDEBUG
   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
   bool toVec = Ty->getTypeID() == Type::VectorTyID;
@@ -1311,7 +1432,7 @@ Constant *ConstantExpr::getTrunc(Constant *C, const Type *Ty) {
   return getFoldedCast(Instruction::Trunc, C, Ty);
 }
 
-Constant *ConstantExpr::getSExt(Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getSExt(Constant *C, Type *Ty) {
 #ifndef NDEBUG
   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
   bool toVec = Ty->getTypeID() == Type::VectorTyID;
@@ -1325,7 +1446,7 @@ Constant *ConstantExpr::getSExt(Constant *C, const Type *Ty) {
   return getFoldedCast(Instruction::SExt, C, Ty);
 }
 
-Constant *ConstantExpr::getZExt(Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getZExt(Constant *C, Type *Ty) {
 #ifndef NDEBUG
   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
   bool toVec = Ty->getTypeID() == Type::VectorTyID;
@@ -1339,7 +1460,7 @@ Constant *ConstantExpr::getZExt(Constant *C, const Type *Ty) {
   return getFoldedCast(Instruction::ZExt, C, Ty);
 }
 
-Constant *ConstantExpr::getFPTrunc(Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getFPTrunc(Constant *C, Type *Ty) {
 #ifndef NDEBUG
   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
   bool toVec = Ty->getTypeID() == Type::VectorTyID;
@@ -1351,7 +1472,7 @@ Constant *ConstantExpr::getFPTrunc(Constant *C, const Type *Ty) {
   return getFoldedCast(Instruction::FPTrunc, C, Ty);
 }
 
-Constant *ConstantExpr::getFPExtend(Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getFPExtend(Constant *C, Type *Ty) {
 #ifndef NDEBUG
   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
   bool toVec = Ty->getTypeID() == Type::VectorTyID;
@@ -1363,7 +1484,7 @@ Constant *ConstantExpr::getFPExtend(Constant *C, const Type *Ty) {
   return getFoldedCast(Instruction::FPExt, C, Ty);
 }
 
-Constant *ConstantExpr::getUIToFP(Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getUIToFP(Constant *C, Type *Ty) {
 #ifndef NDEBUG
   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
   bool toVec = Ty->getTypeID() == Type::VectorTyID;
@@ -1374,7 +1495,7 @@ Constant *ConstantExpr::getUIToFP(Constant *C, const Type *Ty) {
   return getFoldedCast(Instruction::UIToFP, C, Ty);
 }
 
-Constant *ConstantExpr::getSIToFP(Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getSIToFP(Constant *C, Type *Ty) {
 #ifndef NDEBUG
   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
   bool toVec = Ty->getTypeID() == Type::VectorTyID;
@@ -1385,7 +1506,7 @@ Constant *ConstantExpr::getSIToFP(Constant *C, const Type *Ty) {
   return getFoldedCast(Instruction::SIToFP, C, Ty);
 }
 
-Constant *ConstantExpr::getFPToUI(Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getFPToUI(Constant *C, Type *Ty) {
 #ifndef NDEBUG
   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
   bool toVec = Ty->getTypeID() == Type::VectorTyID;
@@ -1396,7 +1517,7 @@ Constant *ConstantExpr::getFPToUI(Constant *C, const Type *Ty) {
   return getFoldedCast(Instruction::FPToUI, C, Ty);
 }
 
-Constant *ConstantExpr::getFPToSI(Constant *C, const Type *Ty) {
+Constant *ConstantExpr::getFPToSI(Constant *C, Type *Ty) {
 #ifndef NDEBUG
   bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
   bool toVec = Ty->getTypeID() == Type::VectorTyID;
@@ -1407,19 +1528,31 @@ Constant *ConstantExpr::getFPToSI(Constant *C, const Type *Ty) {
   return getFoldedCast(Instruction::FPToSI, C, Ty);
 }
 
-Constant *ConstantExpr::getPtrToInt(Constant *C, const Type *DstTy) {
-  assert(C->getType()->isPointerTy() && "PtrToInt source must be pointer");
-  assert(DstTy->isIntegerTy() && "PtrToInt destination must be integral");
+Constant *ConstantExpr::getPtrToInt(Constant *C, Type *DstTy) {
+  assert(C->getType()->getScalarType()->isPointerTy() &&
+         "PtrToInt source must be pointer or pointer vector");
+  assert(DstTy->getScalarType()->isIntegerTy() && 
+         "PtrToInt destination must be integer or integer vector");
+  assert(isa<VectorType>(C->getType()) == isa<VectorType>(DstTy));
+  if (isa<VectorType>(C->getType()))
+    assert(C->getType()->getVectorNumElements()==DstTy->getVectorNumElements()&&
+           "Invalid cast between a different number of vector elements");
   return getFoldedCast(Instruction::PtrToInt, C, DstTy);
 }
 
-Constant *ConstantExpr::getIntToPtr(Constant *C, const Type *DstTy) {
-  assert(C->getType()->isIntegerTy() && "IntToPtr source must be integral");
-  assert(DstTy->isPointerTy() && "IntToPtr destination must be a pointer");
+Constant *ConstantExpr::getIntToPtr(Constant *C, Type *DstTy) {
+  assert(C->getType()->getScalarType()->isIntegerTy() &&
+         "IntToPtr source must be integer or integer vector");
+  assert(DstTy->getScalarType()->isPointerTy() &&
+         "IntToPtr destination must be a pointer or pointer vector");
+  assert(isa<VectorType>(C->getType()) == isa<VectorType>(DstTy));
+  if (isa<VectorType>(C->getType()))
+    assert(C->getType()->getVectorNumElements()==DstTy->getVectorNumElements()&&
+           "Invalid cast between a different number of vector elements");
   return getFoldedCast(Instruction::IntToPtr, C, DstTy);
 }
 
-Constant *ConstantExpr::getBitCast(Constant *C, const Type *DstTy) {
+Constant *ConstantExpr::getBitCast(Constant *C, Type *DstTy) {
   assert(CastInst::castIsValid(Instruction::BitCast, C, DstTy) &&
          "Invalid constantexpr bitcast!");
   
@@ -1508,36 +1641,36 @@ Constant *ConstantExpr::get(unsigned Opcode, Constant *C1, Constant *C2,
   return pImpl->ExprConstants.getOrCreate(C1->getType(), Key);
 }
 
-Constant *ConstantExpr::getSizeOf(const Type* Ty) {
+Constant *ConstantExpr::getSizeOf(Type* Ty) {
   // sizeof is implemented as: (i64) gep (Ty*)null, 1
   // Note that a non-inbounds gep is used, as null isn't within any object.
   Constant *GEPIdx = ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 1);
   Constant *GEP = getGetElementPtr(
-                 Constant::getNullValue(PointerType::getUnqual(Ty)), &GEPIdx, 1);
+                 Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx);
   return getPtrToInt(GEP, 
                      Type::getInt64Ty(Ty->getContext()));
 }
 
-Constant *ConstantExpr::getAlignOf(const Type* Ty) {
+Constant *ConstantExpr::getAlignOf(Type* Ty) {
   // alignof is implemented as: (i64) gep ({i1,Ty}*)null, 0, 1
   // Note that a non-inbounds gep is used, as null isn't within any object.
-  const Type *AligningTy = 
+  Type *AligningTy = 
     StructType::get(Type::getInt1Ty(Ty->getContext()), Ty, NULL);
   Constant *NullPtr = Constant::getNullValue(AligningTy->getPointerTo());
   Constant *Zero = ConstantInt::get(Type::getInt64Ty(Ty->getContext()), 0);
   Constant *One = ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 1);
   Constant *Indices[2] = { Zero, One };
-  Constant *GEP = getGetElementPtr(NullPtr, Indices, 2);
+  Constant *GEP = getGetElementPtr(NullPtr, Indices);
   return getPtrToInt(GEP,
                      Type::getInt64Ty(Ty->getContext()));
 }
 
-Constant *ConstantExpr::getOffsetOf(const StructType* STy, unsigned FieldNo) {
+Constant *ConstantExpr::getOffsetOf(StructType* STy, unsigned FieldNo) {
   return getOffsetOf(STy, ConstantInt::get(Type::getInt32Ty(STy->getContext()),
                                            FieldNo));
 }
 
-Constant *ConstantExpr::getOffsetOf(const Type* Ty, Constant *FieldNo) {
+Constant *ConstantExpr::getOffsetOf(Type* Ty, Constant *FieldNo) {
   // offsetof is implemented as: (i64) gep (Ty*)null, 0, FieldNo
   // Note that a non-inbounds gep is used, as null isn't within any object.
   Constant *GEPIdx[] = {
@@ -1545,7 +1678,7 @@ Constant *ConstantExpr::getOffsetOf(const Type* Ty, Constant *FieldNo) {
     FieldNo
   };
   Constant *GEP = getGetElementPtr(
-                Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx, 2);
+                Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx);
   return getPtrToInt(GEP,
                      Type::getInt64Ty(Ty->getContext()));
 }
@@ -1587,25 +1720,24 @@ Constant *ConstantExpr::getSelect(Constant *C, Constant *V1, Constant *V2) {
   return pImpl->ExprConstants.getOrCreate(V1->getType(), Key);
 }
 
-Constant *ConstantExpr::getGetElementPtr(Constant *C, Value* const *Idxs,
-                                         unsigned NumIdx, bool InBounds) {
-  if (Constant *FC = ConstantFoldGetElementPtr(C, InBounds, Idxs, NumIdx))
+Constant *ConstantExpr::getGetElementPtr(Constant *C, ArrayRef<Value *> Idxs,
+                                         bool InBounds) {
+  if (Constant *FC = ConstantFoldGetElementPtr(C, InBounds, Idxs))
     return FC;          // Fold a few common cases.
 
   // Get the result type of the getelementptr!
-  const Type *Ty = 
-    GetElementPtrInst::getIndexedType(C->getType(), Idxs, Idxs+NumIdx);
+  Type *Ty = GetElementPtrInst::getIndexedType(C->getType(), Idxs);
   assert(Ty && "GEP indices invalid!");
-  unsigned AS = cast<PointerType>(C->getType())->getAddressSpace();
+  unsigned AS = C->getType()->getPointerAddressSpace();
   Type *ReqTy = Ty->getPointerTo(AS);
   
   assert(C->getType()->isPointerTy() &&
          "Non-pointer type for constant GetElementPtr expression");
   // Look up the constant in the table first to ensure uniqueness
   std::vector<Constant*> ArgVec;
-  ArgVec.reserve(NumIdx+1);
+  ArgVec.reserve(1 + Idxs.size());
   ArgVec.push_back(C);
-  for (unsigned i = 0; i != NumIdx; ++i)
+  for (unsigned i = 0, e = Idxs.size(); i != e; ++i)
     ArgVec.push_back(cast<Constant>(Idxs[i]));
   const ExprMapKeyType Key(Instruction::GetElementPtr, ArgVec, 0,
                            InBounds ? GEPOperator::IsInBounds : 0);
@@ -1630,8 +1762,8 @@ ConstantExpr::getICmp(unsigned short pred, Constant *LHS, Constant *RHS) {
   // Get the key type with both the opcode and predicate
   const ExprMapKeyType Key(Instruction::ICmp, ArgVec, pred);
 
-  const Type *ResultTy = Type::getInt1Ty(LHS->getContext());
-  if (const VectorType *VT = dyn_cast<VectorType>(LHS->getType()))
+  Type *ResultTy = Type::getInt1Ty(LHS->getContext());
+  if (VectorType *VT = dyn_cast<VectorType>(LHS->getType()))
     ResultTy = VectorType::get(ResultTy, VT->getNumElements());
 
   LLVMContextImpl *pImpl = LHS->getType()->getContext().pImpl;
@@ -1653,8 +1785,8 @@ ConstantExpr::getFCmp(unsigned short pred, Constant *LHS, Constant *RHS) {
   // Get the key type with both the opcode and predicate
   const ExprMapKeyType Key(Instruction::FCmp, ArgVec, pred);
 
-  const Type *ResultTy = Type::getInt1Ty(LHS->getContext());
-  if (const VectorType *VT = dyn_cast<VectorType>(LHS->getType()))
+  Type *ResultTy = Type::getInt1Ty(LHS->getContext());
+  if (VectorType *VT = dyn_cast<VectorType>(LHS->getType()))
     ResultTy = VectorType::get(ResultTy, VT->getNumElements());
 
   LLVMContextImpl *pImpl = LHS->getType()->getContext().pImpl;
@@ -1676,7 +1808,7 @@ Constant *ConstantExpr::getExtractElement(Constant *Val, Constant *Idx) {
   const ExprMapKeyType Key(Instruction::ExtractElement,ArgVec);
   
   LLVMContextImpl *pImpl = Val->getContext().pImpl;
-  Type *ReqTy = cast<VectorType>(Val->getType())->getElementType();
+  Type *ReqTy = Val->getType()->getVectorElementType();
   return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
 }
 
@@ -1684,8 +1816,8 @@ Constant *ConstantExpr::getInsertElement(Constant *Val, Constant *Elt,
                                          Constant *Idx) {
   assert(Val->getType()->isVectorTy() &&
          "Tried to create insertelement operation on non-vector type!");
-  assert(Elt->getType() == cast<VectorType>(Val->getType())->getElementType()
-         && "Insertelement types must match!");
+  assert(Elt->getType() == Val->getType()->getVectorElementType() &&
+         "Insertelement types must match!");
   assert(Idx->getType()->isIntegerTy(32) &&
          "Insertelement index must be i32 type!");
 
@@ -1709,9 +1841,9 @@ Constant *ConstantExpr::getShuffleVector(Constant *V1, Constant *V2,
   if (Constant *FC = ConstantFoldShuffleVectorInstruction(V1, V2, Mask))
     return FC;          // Fold a few common cases.
 
-  unsigned NElts = cast<VectorType>(Mask->getType())->getNumElements();
-  const Type *EltTy = cast<VectorType>(V1->getType())->getElementType();
-  const Type *ShufTy = VectorType::get(EltTy, NElts);
+  unsigned NElts = Mask->getType()->getVectorNumElements();
+  Type *EltTy = V1->getType()->getVectorElementType();
+  Type *ShufTy = VectorType::get(EltTy, NElts);
 
   // Look up the constant in the table first to ensure uniqueness
   std::vector<Constant*> ArgVec(1, V1);
@@ -1740,7 +1872,7 @@ Constant *ConstantExpr::getExtractValue(Constant *Agg,
   assert(Agg->getType()->isFirstClassType() &&
          "Tried to create extractelement operation on non-first-class type!");
 
-  const Type *ReqTy = ExtractValueInst::getIndexedType(Agg->getType(), Idxs);
+  Type *ReqTy = ExtractValueInst::getIndexedType(Agg->getType(), Idxs);
   (void)ReqTy;
   assert(ReqTy && "extractvalue indices invalid!");
   
@@ -1873,7 +2005,7 @@ const char *ConstantExpr::getOpcodeName() const {
 
 GetElementPtrConstantExpr::
 GetElementPtrConstantExpr(Constant *C, const std::vector<Constant*> &IdxList,
-                          const Type *DestTy)
+                          Type *DestTy)
   : ConstantExpr(DestTy, Instruction::GetElementPtr,
                  OperandTraits<GetElementPtrConstantExpr>::op_end(this)
                  - (IdxList.size()+1), IdxList.size()+1) {
@@ -1882,6 +2014,337 @@ GetElementPtrConstantExpr(Constant *C, const std::vector<Constant*> &IdxList,
     OperandList[i+1] = IdxList[i];
 }
 
+//===----------------------------------------------------------------------===//
+//                       ConstantData* implementations
+
+void ConstantDataArray::anchor() {}
+void ConstantDataVector::anchor() {}
+
+/// getElementType - Return the element type of the array/vector.
+Type *ConstantDataSequential::getElementType() const {
+  return getType()->getElementType();
+}
+
+StringRef ConstantDataSequential::getRawDataValues() const {
+  return StringRef(DataElements, getNumElements()*getElementByteSize());
+}
+
+/// isElementTypeCompatible - Return true if a ConstantDataSequential can be
+/// formed with a vector or array of the specified element type.
+/// ConstantDataArray only works with normal float and int types that are
+/// stored densely in memory, not with things like i42 or x86_f80.
+bool ConstantDataSequential::isElementTypeCompatible(const Type *Ty) {
+  if (Ty->isFloatTy() || Ty->isDoubleTy()) return true;
+  if (const IntegerType *IT = dyn_cast<IntegerType>(Ty)) {
+    switch (IT->getBitWidth()) {
+    case 8:
+    case 16:
+    case 32:
+    case 64:
+      return true;
+    default: break;
+    }
+  }
+  return false;
+}
+
+/// getNumElements - Return the number of elements in the array or vector.
+unsigned ConstantDataSequential::getNumElements() const {
+  if (ArrayType *AT = dyn_cast<ArrayType>(getType()))
+    return AT->getNumElements();
+  return getType()->getVectorNumElements();
+}
+
+
+/// getElementByteSize - Return the size in bytes of the elements in the data.
+uint64_t ConstantDataSequential::getElementByteSize() const {
+  return getElementType()->getPrimitiveSizeInBits()/8;
+}
+
+/// getElementPointer - Return the start of the specified element.
+const char *ConstantDataSequential::getElementPointer(unsigned Elt) const {
+  assert(Elt < getNumElements() && "Invalid Elt");
+  return DataElements+Elt*getElementByteSize();
+}
+
+
+/// isAllZeros - return true if the array is empty or all zeros.
+static bool isAllZeros(StringRef Arr) {
+  for (StringRef::iterator I = Arr.begin(), E = Arr.end(); I != E; ++I)
+    if (*I != 0)
+      return false;
+  return true;
+}
+
+/// getImpl - This is the underlying implementation of all of the
+/// ConstantDataSequential::get methods.  They all thunk down to here, providing
+/// the correct element type.  We take the bytes in as an StringRef because
+/// we *want* an underlying "char*" to avoid TBAA type punning violations.
+Constant *ConstantDataSequential::getImpl(StringRef Elements, Type *Ty) {
+  assert(isElementTypeCompatible(Ty->getSequentialElementType()));
+  // If the elements are all zero or there are no elements, return a CAZ, which
+  // is more dense and canonical.
+  if (isAllZeros(Elements))
+    return ConstantAggregateZero::get(Ty);
+
+  // Do a lookup to see if we have already formed one of these.
+  StringMap<ConstantDataSequential*>::MapEntryTy &Slot =
+    Ty->getContext().pImpl->CDSConstants.GetOrCreateValue(Elements);
+  
+  // The bucket can point to a linked list of different CDS's that have the same
+  // body but different types.  For example, 0,0,0,1 could be a 4 element array
+  // of i8, or a 1-element array of i32.  They'll both end up in the same
+  /// StringMap bucket, linked up by their Next pointers.  Walk the list.
+  ConstantDataSequential **Entry = &Slot.getValue();
+  for (ConstantDataSequential *Node = *Entry; Node != 0;
+       Entry = &Node->Next, Node = *Entry)
+    if (Node->getType() == Ty)
+      return Node;
+  
+  // Okay, we didn't get a hit.  Create a node of the right class, link it in,
+  // and return it.
+  if (isa<ArrayType>(Ty))
+    return *Entry = new ConstantDataArray(Ty, Slot.getKeyData());
+
+  assert(isa<VectorType>(Ty));
+  return *Entry = new ConstantDataVector(Ty, Slot.getKeyData());
+}
+
+void ConstantDataSequential::destroyConstant() {
+  // Remove the constant from the StringMap.
+  StringMap<ConstantDataSequential*> &CDSConstants = 
+    getType()->getContext().pImpl->CDSConstants;
+  
+  StringMap<ConstantDataSequential*>::iterator Slot =
+    CDSConstants.find(getRawDataValues());
+
+  assert(Slot != CDSConstants.end() && "CDS not found in uniquing table");
+
+  ConstantDataSequential **Entry = &Slot->getValue();
+
+  // Remove the entry from the hash table.
+  if ((*Entry)->Next == 0) {
+    // If there is only one value in the bucket (common case) it must be this
+    // entry, and removing the entry should remove the bucket completely.
+    assert((*Entry) == this && "Hash mismatch in ConstantDataSequential");
+    getContext().pImpl->CDSConstants.erase(Slot);
+  } else {
+    // Otherwise, there are multiple entries linked off the bucket, unlink the 
+    // node we care about but keep the bucket around.
+    for (ConstantDataSequential *Node = *Entry; ;
+         Entry = &Node->Next, Node = *Entry) {
+      assert(Node && "Didn't find entry in its uniquing hash table!");
+      // If we found our entry, unlink it from the list and we're done.
+      if (Node == this) {
+        *Entry = Node->Next;
+        break;
+      }
+    }
+  }
+  
+  // If we were part of a list, make sure that we don't delete the list that is
+  // still owned by the uniquing map.
+  Next = 0;
+  
+  // Finally, actually delete it.
+  destroyConstantImpl();
+}
+
+/// get() constructors - Return a constant with array type with an element
+/// count and element type matching the ArrayRef passed in.  Note that this
+/// can return a ConstantAggregateZero object.
+Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<uint8_t> Elts) {
+  Type *Ty = ArrayType::get(Type::getInt8Ty(Context), Elts.size());
+  return getImpl(StringRef((char*)Elts.data(), Elts.size()*1), Ty);
+}
+Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<uint16_t> Elts){
+  Type *Ty = ArrayType::get(Type::getInt16Ty(Context), Elts.size());
+  return getImpl(StringRef((char*)Elts.data(), Elts.size()*2), Ty);
+}
+Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<uint32_t> Elts){
+  Type *Ty = ArrayType::get(Type::getInt32Ty(Context), Elts.size());
+  return getImpl(StringRef((char*)Elts.data(), Elts.size()*4), Ty);
+}
+Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<uint64_t> Elts){
+  Type *Ty = ArrayType::get(Type::getInt64Ty(Context), Elts.size());
+  return getImpl(StringRef((char*)Elts.data(), Elts.size()*8), Ty);
+}
+Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<float> Elts) {
+  Type *Ty = ArrayType::get(Type::getFloatTy(Context), Elts.size());
+  return getImpl(StringRef((char*)Elts.data(), Elts.size()*4), Ty);
+}
+Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<double> Elts) {
+  Type *Ty = ArrayType::get(Type::getDoubleTy(Context), Elts.size());
+  return getImpl(StringRef((char*)Elts.data(), Elts.size()*8), Ty);
+}
+
+/// getString - This method constructs a CDS and initializes it with a text
+/// string. The default behavior (AddNull==true) causes a null terminator to
+/// be placed at the end of the array (increasing the length of the string by
+/// one more than the StringRef would normally indicate.  Pass AddNull=false
+/// to disable this behavior.
+Constant *ConstantDataArray::getString(LLVMContext &Context,
+                                       StringRef Str, bool AddNull) {
+  if (!AddNull)
+    return get(Context, ArrayRef<uint8_t>((uint8_t*)Str.data(), Str.size()));
+  
+  SmallVector<uint8_t, 64> ElementVals;
+  ElementVals.append(Str.begin(), Str.end());
+  ElementVals.push_back(0);
+  return get(Context, ElementVals);
+}
+
+/// get() constructors - Return a constant with vector type with an element
+/// count and element type matching the ArrayRef passed in.  Note that this
+/// can return a ConstantAggregateZero object.
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint8_t> Elts){
+  Type *Ty = VectorType::get(Type::getInt8Ty(Context), Elts.size());
+  return getImpl(StringRef((char*)Elts.data(), Elts.size()*1), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint16_t> Elts){
+  Type *Ty = VectorType::get(Type::getInt16Ty(Context), Elts.size());
+  return getImpl(StringRef((char*)Elts.data(), Elts.size()*2), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint32_t> Elts){
+  Type *Ty = VectorType::get(Type::getInt32Ty(Context), Elts.size());
+  return getImpl(StringRef((char*)Elts.data(), Elts.size()*4), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint64_t> Elts){
+  Type *Ty = VectorType::get(Type::getInt64Ty(Context), Elts.size());
+  return getImpl(StringRef((char*)Elts.data(), Elts.size()*8), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<float> Elts) {
+  Type *Ty = VectorType::get(Type::getFloatTy(Context), Elts.size());
+  return getImpl(StringRef((char*)Elts.data(), Elts.size()*4), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<double> Elts) {
+  Type *Ty = VectorType::get(Type::getDoubleTy(Context), Elts.size());
+  return getImpl(StringRef((char*)Elts.data(), Elts.size()*8), Ty);
+}
+
+Constant *ConstantDataVector::getSplat(unsigned NumElts, Constant *V) {
+  assert(isElementTypeCompatible(V->getType()) &&
+         "Element type not compatible with ConstantData");
+  if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+    if (CI->getType()->isIntegerTy(8)) {
+      SmallVector<uint8_t, 16> Elts(NumElts, CI->getZExtValue());
+      return get(V->getContext(), Elts);
+    }
+    if (CI->getType()->isIntegerTy(16)) {
+      SmallVector<uint16_t, 16> Elts(NumElts, CI->getZExtValue());
+      return get(V->getContext(), Elts);
+    }
+    if (CI->getType()->isIntegerTy(32)) {
+      SmallVector<uint32_t, 16> Elts(NumElts, CI->getZExtValue());
+      return get(V->getContext(), Elts);
+    }
+    assert(CI->getType()->isIntegerTy(64) && "Unsupported ConstantData type");
+    SmallVector<uint64_t, 16> Elts(NumElts, CI->getZExtValue());
+    return get(V->getContext(), Elts);
+  }
+
+  ConstantFP *CFP = cast<ConstantFP>(V);
+  if (CFP->getType()->isFloatTy()) {
+    SmallVector<float, 16> Elts(NumElts, CFP->getValueAPF().convertToFloat());
+    return get(V->getContext(), Elts);
+  }
+  assert(CFP->getType()->isDoubleTy() && "Unsupported ConstantData type");
+  SmallVector<double, 16> Elts(NumElts, CFP->getValueAPF().convertToDouble());
+  return get(V->getContext(), Elts);
+}
+
+
+/// getElementAsInteger - If this is a sequential container of integers (of
+/// any size), return the specified element in the low bits of a uint64_t.
+uint64_t ConstantDataSequential::getElementAsInteger(unsigned Elt) const {
+  assert(isa<IntegerType>(getElementType()) &&
+         "Accessor can only be used when element is an integer");
+  const char *EltPtr = getElementPointer(Elt);
+  
+  // The data is stored in host byte order, make sure to cast back to the right
+  // type to load with the right endianness.
+  switch (getElementType()->getIntegerBitWidth()) {
+  default: assert(0 && "Invalid bitwidth for CDS");
+  case 8:  return *(uint8_t*)EltPtr;
+  case 16: return *(uint16_t*)EltPtr;
+  case 32: return *(uint32_t*)EltPtr;
+  case 64: return *(uint64_t*)EltPtr;
+  }
+}
+
+/// getElementAsAPFloat - If this is a sequential container of floating point
+/// type, return the specified element as an APFloat.
+APFloat ConstantDataSequential::getElementAsAPFloat(unsigned Elt) const {
+  const char *EltPtr = getElementPointer(Elt);
+
+  switch (getElementType()->getTypeID()) {
+  default:
+    assert(0 && "Accessor can only be used when element is float/double!");
+  case Type::FloatTyID: return APFloat(*(float*)EltPtr);
+  case Type::DoubleTyID: return APFloat(*(double*)EltPtr);
+  }
+}
+
+/// getElementAsFloat - If this is an sequential container of floats, return
+/// the specified element as a float.
+float ConstantDataSequential::getElementAsFloat(unsigned Elt) const {
+  assert(getElementType()->isFloatTy() &&
+         "Accessor can only be used when element is a 'float'");
+  return *(float*)getElementPointer(Elt);
+}
+
+/// getElementAsDouble - If this is an sequential container of doubles, return
+/// the specified element as a float.
+double ConstantDataSequential::getElementAsDouble(unsigned Elt) const {
+  assert(getElementType()->isDoubleTy() &&
+         "Accessor can only be used when element is a 'float'");
+  return *(double*)getElementPointer(Elt);
+}
+
+/// getElementAsConstant - Return a Constant for a specified index's element.
+/// Note that this has to compute a new constant to return, so it isn't as
+/// efficient as getElementAsInteger/Float/Double.
+Constant *ConstantDataSequential::getElementAsConstant(unsigned Elt) const {
+  if (getElementType()->isFloatTy() || getElementType()->isDoubleTy())
+    return ConstantFP::get(getContext(), getElementAsAPFloat(Elt));
+  
+  return ConstantInt::get(getElementType(), getElementAsInteger(Elt));
+}
+
+/// isString - This method returns true if this is an array of i8.
+bool ConstantDataSequential::isString() const {
+  return isa<ArrayType>(getType()) && getElementType()->isIntegerTy(8);
+}
+
+/// isCString - This method returns true if the array "isString", ends with a
+/// nul byte, and does not contains any other nul bytes.
+bool ConstantDataSequential::isCString() const {
+  if (!isString())
+    return false;
+  
+  StringRef Str = getAsString();
+  
+  // The last value must be nul.
+  if (Str.back() != 0) return false;
+  
+  // Other elements must be non-nul.
+  return Str.drop_back().find(0) == StringRef::npos;
+}
+
+/// getSplatValue - If this is a splat constant, meaning that all of the
+/// elements have the same value, return that value. Otherwise return NULL.
+Constant *ConstantDataVector::getSplatValue() const {
+  const char *Base = getRawDataValues().data();
+  
+  // Compare elements 1+ to the 0'th element.
+  unsigned EltSize = getElementByteSize();
+  for (unsigned i = 1, e = getNumElements(); i != e; ++i)
+    if (memcmp(Base, Base+i*EltSize, EltSize))
+      return 0;
+  
+  // If they're all the same, return the 0th one as a representative.
+  return getElementAsConstant(0);
+}
 
 //===----------------------------------------------------------------------===//
 //                replaceUsesOfWithOnConstant implementations
@@ -1913,33 +2376,25 @@ void ConstantArray::replaceUsesOfWithOnConstant(Value *From, Value *To,
 
   // Fill values with the modified operands of the constant array.  Also, 
   // compute whether this turns into an all-zeros array.
-  bool isAllZeros = false;
   unsigned NumUpdated = 0;
-  if (!ToC->isNullValue()) {
-    for (Use *O = OperandList, *E = OperandList+getNumOperands(); O != E; ++O) {
-      Constant *Val = cast<Constant>(O->get());
-      if (Val == From) {
-        Val = ToC;
-        ++NumUpdated;
-      }
-      Values.push_back(Val);
-    }
-  } else {
-    isAllZeros = true;
-    for (Use *O = OperandList, *E = OperandList+getNumOperands();O != E; ++O) {
-      Constant *Val = cast<Constant>(O->get());
-      if (Val == From) {
-        Val = ToC;
-        ++NumUpdated;
-      }
-      Values.push_back(Val);
-      if (isAllZeros) isAllZeros = Val->isNullValue();
+  
+  // Keep track of whether all the values in the array are "ToC".
+  bool AllSame = true;
+  for (Use *O = OperandList, *E = OperandList+getNumOperands(); O != E; ++O) {
+    Constant *Val = cast<Constant>(O->get());
+    if (Val == From) {
+      Val = ToC;
+      ++NumUpdated;
     }
+    Values.push_back(Val);
+    AllSame = Val == ToC;
   }
   
   Constant *Replacement = 0;
-  if (isAllZeros) {
+  if (AllSame && ToC->isNullValue()) {
     Replacement = ConstantAggregateZero::get(getType());
+  } else if (AllSame && isa<UndefValue>(ToC)) {
+    Replacement = UndefValue::get(getType());
   } else {
     // Check to see if we have this array type already.
     bool Exists;
@@ -1975,7 +2430,7 @@ void ConstantArray::replaceUsesOfWithOnConstant(Value *From, Value *To,
   assert(Replacement != this && "I didn't contain From!");
   
   // Everyone using this now uses the replacement.
-  uncheckedReplaceAllUsesWith(Replacement);
+  replaceAllUsesWith(Replacement);
   
   // Delete the old constant!
   destroyConstant();
@@ -1999,16 +2454,24 @@ void ConstantStruct::replaceUsesOfWithOnConstant(Value *From, Value *To,
   // Fill values with the modified operands of the constant struct.  Also, 
   // compute whether this turns into an all-zeros struct.
   bool isAllZeros = false;
-  if (!ToC->isNullValue()) {
-    for (Use *O = OperandList, *E = OperandList + getNumOperands(); O != E; ++O)
-      Values.push_back(cast<Constant>(O->get()));
-  } else {
+  bool isAllUndef = false;
+  if (ToC->isNullValue()) {
     isAllZeros = true;
     for (Use *O = OperandList, *E = OperandList+getNumOperands(); O != E; ++O) {
       Constant *Val = cast<Constant>(O->get());
       Values.push_back(Val);
       if (isAllZeros) isAllZeros = Val->isNullValue();
     }
+  } else if (isa<UndefValue>(ToC)) {
+    isAllUndef = true;
+    for (Use *O = OperandList, *E = OperandList+getNumOperands(); O != E; ++O) {
+      Constant *Val = cast<Constant>(O->get());
+      Values.push_back(Val);
+      if (isAllUndef) isAllUndef = isa<UndefValue>(Val);
+    }
+  } else {
+    for (Use *O = OperandList, *E = OperandList + getNumOperands(); O != E; ++O)
+      Values.push_back(cast<Constant>(O->get()));
   }
   Values[OperandToUpdate] = ToC;
   
@@ -2017,6 +2480,8 @@ void ConstantStruct::replaceUsesOfWithOnConstant(Value *From, Value *To,
   Constant *Replacement = 0;
   if (isAllZeros) {
     Replacement = ConstantAggregateZero::get(getType());
+  } else if (isAllUndef) {
+    Replacement = UndefValue::get(getType());
   } else {
     // Check to see if we have this struct type already.
     bool Exists;
@@ -2041,7 +2506,7 @@ void ConstantStruct::replaceUsesOfWithOnConstant(Value *From, Value *To,
   assert(Replacement != this && "I didn't contain From!");
   
   // Everyone using this now uses the replacement.
-  uncheckedReplaceAllUsesWith(Replacement);
+  replaceAllUsesWith(Replacement);
   
   // Delete the old constant!
   destroyConstant();
@@ -2063,7 +2528,7 @@ void ConstantVector::replaceUsesOfWithOnConstant(Value *From, Value *To,
   assert(Replacement != this && "I didn't contain From!");
   
   // Everyone using this now uses the replacement.
-  uncheckedReplaceAllUsesWith(Replacement);
+  replaceAllUsesWith(Replacement);
   
   // Delete the old constant!
   destroyConstant();
@@ -2086,8 +2551,7 @@ void ConstantExpr::replaceUsesOfWithOnConstant(Value *From, Value *ToV,
       if (Val == From) Val = To;
       Indices.push_back(Val);
     }
-    Replacement = ConstantExpr::getGetElementPtr(Pointer,
-                                                 &Indices[0], Indices.size(),
+    Replacement = ConstantExpr::getGetElementPtr(Pointer, Indices,
                                          cast<GEPOperator>(this)->isInBounds());
   } else if (getOpcode() == Instruction::ExtractValue) {
     Constant *Agg = getOperand(0);
@@ -2155,13 +2619,12 @@ void ConstantExpr::replaceUsesOfWithOnConstant(Value *From, Value *ToV,
     Replacement = ConstantExpr::get(getOpcode(), C1, C2, SubclassOptionalData);
   } else {
     llvm_unreachable("Unknown ConstantExpr type!");
-    return;
   }
   
   assert(Replacement != this && "I didn't contain From!");
   
   // Everyone using this now uses the replacement.
-  uncheckedReplaceAllUsesWith(Replacement);
+  replaceAllUsesWith(Replacement);
   
   // Delete the old constant!
   destroyConstant();