vendor/llvm/llvm-trunk-r178860

1 files changed, 2779 insertions, 0 deletions

diff --git a/lib/IR/Constants.cpp b/lib/IR/Constants.cpp
new file mode 100644
index 000000000000..1abb65643559
--- /dev/null
+++ b/lib/IR/Constants.cpp
@@ -0,0 +1,2779 @@
+//===-- Constants.cpp - Implement Constant nodes --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the Constant* classes.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/IR/Constants.h"
+#include "ConstantFold.h"
+#include "LLVMContextImpl.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/FoldingSet.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/GlobalValue.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Operator.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/GetElementPtrTypeIterator.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <cstdarg>
+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))
+    return CFP->isZero() && CFP->isNegative();
+
+  // Equivalent for a vector of -0.0's.
+  if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
+    if (ConstantFP *SplatCFP = dyn_cast_or_null<ConstantFP>(CV->getSplatValue()))
+      if (SplatCFP && SplatCFP->isZero() && SplatCFP->isNegative())
+        return true;
+
+  // We've already handled true FP case; any other FP vectors can't represent -0.0.
+  if (getType()->isFPOrFPVectorTy())
+    return false;
+
+  // Otherwise, just use +0.0.
+  return isNullValue();
+}
+
+// Return true iff this constant is positive zero (floating point), negative
+// zero (floating point), or a null value.
+bool Constant::isZeroValue() const {
+  // Floating point values have an explicit -0.0 value.
+  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
+    return CFP->isZero();
+
+  // Otherwise, just use +0.0.
+  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(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));
+  case Type::DoubleTyID:
+    return ConstantFP::get(Ty->getContext(),
+                           APFloat::getZero(APFloat::IEEEdouble));
+  case Type::X86_FP80TyID:
+    return ConstantFP::get(Ty->getContext(),
+                           APFloat::getZero(APFloat::x87DoubleExtended));
+  case Type::FP128TyID:
+    return ConstantFP::get(Ty->getContext(),
+                           APFloat::getZero(APFloat::IEEEquad));
+  case Type::PPC_FP128TyID:
+    return ConstantFP::get(Ty->getContext(),
+                           APFloat(APFloat::PPCDoubleDouble,
+                                   APInt::getNullValue(128)));
+  case Type::PointerTyID:
+    return ConstantPointerNull::get(cast<PointerType>(Ty));
+  case Type::StructTyID:
+  case Type::ArrayTyID:
+  case Type::VectorTyID:
+    return ConstantAggregateZero::get(Ty);
+  default:
+    // Function, Label, or Opaque type?
+    llvm_unreachable("Cannot create a null constant of that type!");
+  }
+}
+
+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 (PointerType *PTy = dyn_cast<PointerType>(ScalarTy))
+    C = ConstantExpr::getIntToPtr(C, PTy);
+
+  // Broadcast a scalar to a vector, if necessary.
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    C = ConstantVector::getSplat(VTy->getNumElements(), C);
+
+  return C;
+}
+
+Constant *Constant::getAllOnesValue(Type *Ty) {
+  if (IntegerType *ITy = dyn_cast<IntegerType>(Ty))
+    return ConstantInt::get(Ty->getContext(),
+                            APInt::getAllOnesValue(ITy->getBitWidth()));
+
+  if (Ty->isFloatingPointTy()) {
+    APFloat FL = APFloat::getAllOnesValue(Ty->getPrimitiveSizeInBits(),
+                                          !Ty->isPPC_FP128Ty());
+    return ConstantFP::get(Ty->getContext(), FL);
+  }
+
+  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 Elt < CDS->getNumElements() ? CDS->getElementAsConstant(Elt) : 0;
+  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
+  // constants are implicitly dependent on the module that is being deleted,
+  // but they don't know that.  Because we only find out when the CPV is
+  // deleted, we must now notify all of our users (that should only be
+  // Constants) that they are, in fact, invalid now and should be deleted.
+  //
+  while (!use_empty()) {
+    Value *V = use_back();
+#ifndef NDEBUG      // Only in -g mode...
+    if (!isa<Constant>(V)) {
+      dbgs() << "While deleting: " << *this
+             << "\n\nUse still stuck around after Def is destroyed: "
+             << *V << "\n\n";
+    }
+#endif
+    assert(isa<Constant>(V) && "References remain to Constant being destroyed");
+    cast<Constant>(V)->destroyConstant();
+
+    // The constant should remove itself from our use list...
+    assert((use_empty() || use_back() != V) && "Constant not removed!");
+  }
+
+  // Value has no outstanding references it is safe to delete it now...
+  delete this;
+}
+
+/// canTrap - Return true if evaluation of this constant could trap.  This is
+/// true for things like constant expressions that could divide by zero.
+bool Constant::canTrap() const {
+  assert(getType()->isFirstClassType() && "Cannot evaluate aggregate vals!");
+  // The only thing that could possibly trap are constant exprs.
+  const ConstantExpr *CE = dyn_cast<ConstantExpr>(this);
+  if (!CE) return false;
+
+  // ConstantExpr traps if any operands can trap.
+  for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
+    if (CE->getOperand(i)->canTrap())
+      return true;
+
+  // Otherwise, only specific operations can trap.
+  switch (CE->getOpcode()) {
+  default:
+    return false;
+  case Instruction::UDiv:
+  case Instruction::SDiv:
+  case Instruction::FDiv:
+  case Instruction::URem:
+  case Instruction::SRem:
+  case Instruction::FRem:
+    // Div and rem can trap if the RHS is not known to be non-zero.
+    if (!isa<ConstantInt>(CE->getOperand(1)) ||CE->getOperand(1)->isNullValue())
+      return true;
+    return false;
+  }
+}
+
+/// isThreadDependent - Return true if the value can vary between threads.
+bool Constant::isThreadDependent() const {
+  SmallPtrSet<const Constant*, 64> Visited;
+  SmallVector<const Constant*, 64> WorkList;
+  WorkList.push_back(this);
+  Visited.insert(this);
+
+  while (!WorkList.empty()) {
+    const Constant *C = WorkList.pop_back_val();
+
+    if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) {
+      if (GV->isThreadLocal())
+        return true;
+    }
+
+    for (unsigned I = 0, E = C->getNumOperands(); I != E; ++I) {
+      const Constant *D = dyn_cast<Constant>(C->getOperand(I));
+      if (!D)
+        continue;
+      if (Visited.insert(D))
+        WorkList.push_back(D);
+    }
+  }
+
+  return false;
+}
+
+/// isConstantUsed - Return true if the constant has users other than constant
+/// exprs and other dangling things.
+bool Constant::isConstantUsed() const {
+  for (const_use_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) {
+    const Constant *UC = dyn_cast<Constant>(*UI);
+    if (UC == 0 || isa<GlobalValue>(UC))
+      return true;
+
+    if (UC->isConstantUsed())
+      return true;
+  }
+  return false;
+}
+
+
+
+/// getRelocationInfo - This method classifies the entry according to
+/// whether or not it may generate a relocation entry.  This must be
+/// conservative, so if it might codegen to a relocatable entry, it should say
+/// so.  The return values are:
+/// 
+///  NoRelocation: This constant pool entry is guaranteed to never have a
+///     relocation applied to it (because it holds a simple constant like
+///     '4').
+///  LocalRelocation: This entry has relocations, but the entries are
+///     guaranteed to be resolvable by the static linker, so the dynamic
+///     linker will never see them.
+///  GlobalRelocations: This entry may have arbitrary relocations.
+///
+/// FIXME: This really should not be in IR.
+Constant::PossibleRelocationsTy Constant::getRelocationInfo() const {
+  if (const GlobalValue *GV = dyn_cast<GlobalValue>(this)) {
+    if (GV->hasLocalLinkage() || GV->hasHiddenVisibility())
+      return LocalRelocation;  // Local to this file/library.
+    return GlobalRelocations;    // Global reference.
+  }
+  
+  if (const BlockAddress *BA = dyn_cast<BlockAddress>(this))
+    return BA->getFunction()->getRelocationInfo();
+  
+  // While raw uses of blockaddress need to be relocated, differences between
+  // two of them don't when they are for labels in the same function.  This is a
+  // common idiom when creating a table for the indirect goto extension, so we
+  // handle it efficiently here.
+  if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(this))
+    if (CE->getOpcode() == Instruction::Sub) {
+      ConstantExpr *LHS = dyn_cast<ConstantExpr>(CE->getOperand(0));
+      ConstantExpr *RHS = dyn_cast<ConstantExpr>(CE->getOperand(1));
+      if (LHS && RHS &&
+          LHS->getOpcode() == Instruction::PtrToInt &&
+          RHS->getOpcode() == Instruction::PtrToInt &&
+          isa<BlockAddress>(LHS->getOperand(0)) &&
+          isa<BlockAddress>(RHS->getOperand(0)) &&
+          cast<BlockAddress>(LHS->getOperand(0))->getFunction() ==
+            cast<BlockAddress>(RHS->getOperand(0))->getFunction())
+        return NoRelocation;
+    }
+
+  PossibleRelocationsTy Result = NoRelocation;
+  for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
+    Result = std::max(Result,
+                      cast<Constant>(getOperand(i))->getRelocationInfo());
+
+  return Result;
+}
+
+/// removeDeadUsersOfConstant - If the specified constantexpr is dead, remove
+/// it.  This involves recursively eliminating any dead users of the
+/// constantexpr.
+static bool removeDeadUsersOfConstant(const Constant *C) {
+  if (isa<GlobalValue>(C)) return false; // Cannot remove this
+
+  while (!C->use_empty()) {
+    const Constant *User = dyn_cast<Constant>(C->use_back());
+    if (!User) return false; // Non-constant usage;
+    if (!removeDeadUsersOfConstant(User))
+      return false; // Constant wasn't dead
+  }
+
+  const_cast<Constant*>(C)->destroyConstant();
+  return true;
+}
+
+
+/// removeDeadConstantUsers - If there are any dead constant users dangling
+/// off of this constant, remove them.  This method is useful for clients
+/// that want to check to see if a global is unused, but don't want to deal
+/// with potentially dead constants hanging off of the globals.
+void Constant::removeDeadConstantUsers() const {
+  Value::const_use_iterator I = use_begin(), E = use_end();
+  Value::const_use_iterator LastNonDeadUser = E;
+  while (I != E) {
+    const Constant *User = dyn_cast<Constant>(*I);
+    if (User == 0) {
+      LastNonDeadUser = I;
+      ++I;
+      continue;
+    }
+
+    if (!removeDeadUsersOfConstant(User)) {
+      // If the constant wasn't dead, remember that this was the last live use
+      // and move on to the next constant.
+      LastNonDeadUser = I;
+      ++I;
+      continue;
+    }
+
+    // If the constant was dead, then the iterator is invalidated.
+    if (LastNonDeadUser == E) {
+      I = use_begin();
+      if (I == E) break;
+    } else {
+      I = LastNonDeadUser;
+      ++I;
+    }
+  }
+}
+
+
+
+//===----------------------------------------------------------------------===//
+//                                ConstantInt
+//===----------------------------------------------------------------------===//
+
+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");
+}
+
+ConstantInt *ConstantInt::getTrue(LLVMContext &Context) {
+  LLVMContextImpl *pImpl = Context.pImpl;
+  if (!pImpl->TheTrueVal)
+    pImpl->TheTrueVal = ConstantInt::get(Type::getInt1Ty(Context), 1);
+  return pImpl->TheTrueVal;
+}
+
+ConstantInt *ConstantInt::getFalse(LLVMContext &Context) {
+  LLVMContextImpl *pImpl = Context.pImpl;
+  if (!pImpl->TheFalseVal)
+    pImpl->TheFalseVal = ConstantInt::get(Type::getInt1Ty(Context), 0);
+  return pImpl->TheFalseVal;
+}
+
+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.");
+  return ConstantVector::getSplat(VTy->getNumElements(),
+                                  ConstantInt::getTrue(Ty->getContext()));
+}
+
+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.");
+  return ConstantVector::getSplat(VTy->getNumElements(),
+                                  ConstantInt::getFalse(Ty->getContext()));
+}
+
+
+// Get a ConstantInt from an APInt. Note that the value stored in the DenseMap 
+// as the key, is a DenseMapAPIntKeyInfo::KeyTy which has provided the
+// operator== and operator!= to ensure that the DenseMap doesn't attempt to
+// compare APInt's of different widths, which would violate an APInt class
+// 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.
+  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]; 
+  if (!Slot) Slot = new ConstantInt(ITy, V);
+  return Slot;
+}
+
+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 (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getNumElements(), C);
+
+  return C;
+}
+
+ConstantInt *ConstantInt::get(IntegerType *Ty, uint64_t V, 
+                              bool isSigned) {
+  return get(Ty->getContext(), APInt(Ty->getBitWidth(), V, isSigned));
+}
+
+ConstantInt *ConstantInt::getSigned(IntegerType *Ty, int64_t V) {
+  return get(Ty, V, true);
+}
+
+Constant *ConstantInt::getSigned(Type *Ty, int64_t V) {
+  return get(Ty, V, true);
+}
+
+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 (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getNumElements(), C);
+
+  return C;
+}
+
+ConstantInt *ConstantInt::get(IntegerType* Ty, StringRef Str,
+                              uint8_t radix) {
+  return get(Ty->getContext(), APInt(Ty->getBitWidth(), Str, radix));
+}
+
+//===----------------------------------------------------------------------===//
+//                                ConstantFP
+//===----------------------------------------------------------------------===//
+
+static const fltSemantics *TypeToFloatSemantics(Type *Ty) {
+  if (Ty->isHalfTy())
+    return &APFloat::IEEEhalf;
+  if (Ty->isFloatTy())
+    return &APFloat::IEEEsingle;
+  if (Ty->isDoubleTy())
+    return &APFloat::IEEEdouble;
+  if (Ty->isX86_FP80Ty())
+    return &APFloat::x87DoubleExtended;
+  else if (Ty->isFP128Ty())
+    return &APFloat::IEEEquad;
+
+  assert(Ty->isPPC_FP128Ty() && "Unknown FP format");
+  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(Type *Ty, double V) {
+  LLVMContext &Context = Ty->getContext();
+
+  APFloat FV(V);
+  bool ignored;
+  FV.convert(*TypeToFloatSemantics(Ty->getScalarType()),
+             APFloat::rmNearestTiesToEven, &ignored);
+  Constant *C = get(Context, FV);
+
+  // For vectors, broadcast the value.
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getNumElements(), C);
+
+  return C;
+}
+
+
+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 (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getNumElements(), C);
+
+  return C; 
+}
+
+
+ConstantFP *ConstantFP::getNegativeZero(Type *Ty) {
+  LLVMContext &Context = Ty->getContext();
+  APFloat apf = cast<ConstantFP>(Constant::getNullValue(Ty))->getValueAPF();
+  apf.changeSign();
+  return get(Context, apf);
+}
+
+
+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);
+}
+
+
+// ConstantFP accessors.
+ConstantFP* ConstantFP::get(LLVMContext &Context, const APFloat& V) {
+  DenseMapAPFloatKeyInfo::KeyTy Key(V);
+
+  LLVMContextImpl* pImpl = Context.pImpl;
+
+  ConstantFP *&Slot = pImpl->FPConstants[Key];
+
+  if (!Slot) {
+    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);
+    else if (&V.getSemantics() == &APFloat::x87DoubleExtended)
+      Ty = Type::getX86_FP80Ty(Context);
+    else if (&V.getSemantics() == &APFloat::IEEEquad)
+      Ty = Type::getFP128Ty(Context);
+    else {
+      assert(&V.getSemantics() == &APFloat::PPCDoubleDouble && 
+             "Unknown FP format");
+      Ty = Type::getPPC_FP128Ty(Context);
+    }
+    Slot = new ConstantFP(Ty, V);
+  }
+
+  return Slot;
+}
+
+ConstantFP *ConstantFP::getInfinity(Type *Ty, bool Negative) {
+  const fltSemantics &Semantics = *TypeToFloatSemantics(Ty);
+  return ConstantFP::get(Ty->getContext(),
+                         APFloat::getInf(Semantics, Negative));
+}
+
+ConstantFP::ConstantFP(Type *Ty, const APFloat& V)
+  : Constant(Ty, ConstantFPVal, 0, 0), Val(V) {
+  assert(&V.getSemantics() == TypeToFloatSemantics(Ty) &&
+         "FP type Mismatch");
+}
+
+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
+//===----------------------------------------------------------------------===//
+
+template <typename ItTy, typename EltTy>
+static bool rangeOnlyContains(ItTy Start, ItTy End, EltTy Elt) {
+  for (; Start != End; ++Start)
+    if (*Start != Elt)
+      return false;
+  return true;
+}
+
+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");
+  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!");
+  std::copy(V.begin(), V.end(), op_begin());
+}
+
+Constant *ConstantArray::get(ArrayType *Ty, ArrayRef<Constant*> V) {
+  // Empty arrays are canonicalized to ConstantAggregateZero.
+  if (V.empty())
+    return ConstantAggregateZero::get(Ty);
+
+  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.  If
+  // all undef, return an UndefValue, if "all simple", then return a
+  // ConstantDataArray.
+  Constant *C = V[0];
+  if (isa<UndefValue>(C) && rangeOnlyContains(V.begin(), V.end(), C))
+    return UndefValue::get(Ty);
+
+  if (C->isNullValue() && rangeOnlyContains(V.begin(), V.end(), C))
+    return ConstantAggregateZero::get(Ty);
+
+  // Check to see if all of the elements are ConstantFP or ConstantInt and if
+  // the element type is compatible with ConstantDataVector.  If so, use it.
+  if (ConstantDataSequential::isElementTypeCompatible(C->getType())) {
+    // We speculatively build the elements here even if it turns out that there
+    // is a constantexpr or something else weird in the array, since it is so
+    // uncommon for that to happen.
+    if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
+      if (CI->getType()->isIntegerTy(8)) {
+        SmallVector<uint8_t, 16> Elts;
+        for (unsigned i = 0, e = V.size(); i != e; ++i)
+          if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i]))
+            Elts.push_back(CI->getZExtValue());
+          else
+            break;
+        if (Elts.size() == V.size())
+          return ConstantDataArray::get(C->getContext(), Elts);
+      } else if (CI->getType()->isIntegerTy(16)) {
+        SmallVector<uint16_t, 16> Elts;
+        for (unsigned i = 0, e = V.size(); i != e; ++i)
+          if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i]))
+            Elts.push_back(CI->getZExtValue());
+          else
+            break;
+        if (Elts.size() == V.size())
+          return ConstantDataArray::get(C->getContext(), Elts);
+      } else if (CI->getType()->isIntegerTy(32)) {
+        SmallVector<uint32_t, 16> Elts;
+        for (unsigned i = 0, e = V.size(); i != e; ++i)
+          if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i]))
+            Elts.push_back(CI->getZExtValue());
+          else
+            break;
+        if (Elts.size() == V.size())
+          return ConstantDataArray::get(C->getContext(), Elts);
+      } else if (CI->getType()->isIntegerTy(64)) {
+        SmallVector<uint64_t, 16> Elts;
+        for (unsigned i = 0, e = V.size(); i != e; ++i)
+          if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i]))
+            Elts.push_back(CI->getZExtValue());
+          else
+            break;
+        if (Elts.size() == V.size())
+          return ConstantDataArray::get(C->getContext(), Elts);
+      }
+    }
+
+    if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
+      if (CFP->getType()->isFloatTy()) {
+        SmallVector<float, 16> Elts;
+        for (unsigned i = 0, e = V.size(); i != e; ++i)
+          if (ConstantFP *CFP = dyn_cast<ConstantFP>(V[i]))
+            Elts.push_back(CFP->getValueAPF().convertToFloat());
+          else
+            break;
+        if (Elts.size() == V.size())
+          return ConstantDataArray::get(C->getContext(), Elts);
+      } else if (CFP->getType()->isDoubleTy()) {
+        SmallVector<double, 16> Elts;
+        for (unsigned i = 0, e = V.size(); i != e; ++i)
+          if (ConstantFP *CFP = dyn_cast<ConstantFP>(V[i]))
+            Elts.push_back(CFP->getValueAPF().convertToDouble());
+          else
+            break;
+        if (Elts.size() == V.size())
+          return ConstantDataArray::get(C->getContext(), Elts);
+      }
+    }
+  }
+
+  // Otherwise, we really do want to create a ConstantArray.
+  return pImpl->ArrayConstants.getOrCreate(Ty, V);
+}
+
+/// getTypeForElements - Return an anonymous struct type to use for a constant
+/// with the specified set of elements.  The list must not be empty.
+StructType *ConstantStruct::getTypeForElements(LLVMContext &Context,
+                                               ArrayRef<Constant*> V,
+                                               bool Packed) {
+  unsigned VecSize = V.size();
+  SmallVector<Type*, 16> EltTypes(VecSize);
+  for (unsigned i = 0; i != VecSize; ++i)
+    EltTypes[i] = V[i]->getType();
+
+  return StructType::get(Context, EltTypes, Packed);
+}
+
+
+StructType *ConstantStruct::getTypeForElements(ArrayRef<Constant*> V,
+                                               bool Packed) {
+  assert(!V.empty() &&
+         "ConstantStruct::getTypeForElements cannot be called on empty list");
+  return getTypeForElements(V[0]->getContext(), V, Packed);
+}
+
+
+ConstantStruct::ConstantStruct(StructType *T, ArrayRef<Constant *> V)
+  : Constant(T, ConstantStructVal,
+             OperandTraits<ConstantStruct>::op_end(this) - V.size(),
+             V.size()) {
+  assert(V.size() == T->getNumElements() &&
+         "Invalid initializer vector for constant structure");
+  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!");
+  std::copy(V.begin(), V.end(), op_begin());
+}
+
+// ConstantStruct accessors.
+Constant *ConstantStruct::get(StructType *ST, ArrayRef<Constant*> V) {
+  assert((ST->isOpaque() || ST->getNumElements() == V.size()) &&
+         "Incorrect # elements specified to ConstantStruct::get");
+
+  // 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(StructType *T, ...) {
+  va_list ap;
+  SmallVector<Constant*, 8> Values;
+  va_start(ap, T);
+  while (Constant *Val = va_arg(ap, llvm::Constant*))
+    Values.push_back(Val);
+  va_end(ap);
+  return get(T, Values);
+}
+
+ConstantVector::ConstantVector(VectorType *T, ArrayRef<Constant *> V)
+  : Constant(T, ConstantVectorVal,
+             OperandTraits<ConstantVector>::op_end(this) - V.size(),
+             V.size()) {
+  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!");
+  std::copy(V.begin(), V.end(), op_begin());
+}
+
+// ConstantVector accessors.
+Constant *ConstantVector::get(ArrayRef<Constant*> V) {
+  assert(!V.empty() && "Vectors can't be empty");
+  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
+  // ConstantAggregateZero or UndefValue.
+  Constant *C = V[0];
+  bool isZero = C->isNullValue();
+  bool isUndef = isa<UndefValue>(C);
+
+  if (isZero || isUndef) {
+    for (unsigned i = 1, e = V.size(); i != e; ++i)
+      if (V[i] != C) {
+        isZero = isUndef = false;
+        break;
+      }
+  }
+
+  if (isZero)
+    return ConstantAggregateZero::get(T);
+  if (isUndef)
+    return UndefValue::get(T);
+
+  // Check to see if all of the elements are ConstantFP or ConstantInt and if
+  // the element type is compatible with ConstantDataVector.  If so, use it.
+  if (ConstantDataSequential::isElementTypeCompatible(C->getType())) {
+    // We speculatively build the elements here even if it turns out that there
+    // is a constantexpr or something else weird in the array, since it is so
+    // uncommon for that to happen.
+    if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
+      if (CI->getType()->isIntegerTy(8)) {
+        SmallVector<uint8_t, 16> Elts;
+        for (unsigned i = 0, e = V.size(); i != e; ++i)
+          if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i]))
+            Elts.push_back(CI->getZExtValue());
+          else
+            break;
+        if (Elts.size() == V.size())
+          return ConstantDataVector::get(C->getContext(), Elts);
+      } else if (CI->getType()->isIntegerTy(16)) {
+        SmallVector<uint16_t, 16> Elts;
+        for (unsigned i = 0, e = V.size(); i != e; ++i)
+          if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i]))
+            Elts.push_back(CI->getZExtValue());
+          else
+            break;
+        if (Elts.size() == V.size())
+          return ConstantDataVector::get(C->getContext(), Elts);
+      } else if (CI->getType()->isIntegerTy(32)) {
+        SmallVector<uint32_t, 16> Elts;
+        for (unsigned i = 0, e = V.size(); i != e; ++i)
+          if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i]))
+            Elts.push_back(CI->getZExtValue());
+          else
+            break;
+        if (Elts.size() == V.size())
+          return ConstantDataVector::get(C->getContext(), Elts);
+      } else if (CI->getType()->isIntegerTy(64)) {
+        SmallVector<uint64_t, 16> Elts;
+        for (unsigned i = 0, e = V.size(); i != e; ++i)
+          if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i]))
+            Elts.push_back(CI->getZExtValue());
+          else
+            break;
+        if (Elts.size() == V.size())
+          return ConstantDataVector::get(C->getContext(), Elts);
+      }
+    }
+
+    if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
+      if (CFP->getType()->isFloatTy()) {
+        SmallVector<float, 16> Elts;
+        for (unsigned i = 0, e = V.size(); i != e; ++i)
+          if (ConstantFP *CFP = dyn_cast<ConstantFP>(V[i]))
+            Elts.push_back(CFP->getValueAPF().convertToFloat());
+          else
+            break;
+        if (Elts.size() == V.size())
+          return ConstantDataVector::get(C->getContext(), Elts);
+      } else if (CFP->getType()->isDoubleTy()) {
+        SmallVector<double, 16> Elts;
+        for (unsigned i = 0, e = V.size(); i != e; ++i)
+          if (ConstantFP *CFP = dyn_cast<ConstantFP>(V[i]))
+            Elts.push_back(CFP->getValueAPF().convertToDouble());
+          else
+            break;
+        if (Elts.size() == V.size())
+          return ConstantDataVector::get(C->getContext(), Elts);
+      }
+    }
+  }
+
+  // Otherwise, the element type isn't compatible with ConstantDataVector, or
+  // the operand list constants a ConstantExpr or something else strange.
+  return pImpl->VectorConstants.getOrCreate(T, V);
+}
+
+Constant *ConstantVector::getSplat(unsigned NumElts, Constant *V) {
+  // If this splat is compatible with ConstantDataVector, use it instead of
+  // ConstantVector.
+  if ((isa<ConstantFP>(V) || isa<ConstantInt>(V)) &&
+      ConstantDataSequential::isElementTypeCompatible(V->getType()))
+    return ConstantDataVector::getSplat(NumElts, 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
+bool ConstantExpr::isCast() const {
+  return Instruction::isCast(getOpcode());
+}
+
+bool ConstantExpr::isCompare() const {
+  return getOpcode() == Instruction::ICmp || getOpcode() == Instruction::FCmp;
+}
+
+bool ConstantExpr::isGEPWithNoNotionalOverIndexing() const {
+  if (getOpcode() != Instruction::GetElementPtr) return false;
+
+  gep_type_iterator GEPI = gep_type_begin(this), E = gep_type_end(this);
+  User::const_op_iterator OI = llvm::next(this->op_begin());
+
+  // Skip the first index, as it has no static limit.
+  ++GEPI;
+  ++OI;
+
+  // The remaining indices must be compile-time known integers within the
+  // bounds of the corresponding notional static array types.
+  for (; GEPI != E; ++GEPI, ++OI) {
+    ConstantInt *CI = dyn_cast<ConstantInt>(*OI);
+    if (!CI) return false;
+    if (ArrayType *ATy = dyn_cast<ArrayType>(*GEPI))
+      if (CI->getValue().getActiveBits() > 64 ||
+          CI->getZExtValue() >= ATy->getNumElements())
+        return false;
+  }
+
+  // All the indices checked out.
+  return true;
+}
+
+bool ConstantExpr::hasIndices() const {
+  return getOpcode() == Instruction::ExtractValue ||
+         getOpcode() == Instruction::InsertValue;
+}
+
+ArrayRef<unsigned> ConstantExpr::getIndices() const {
+  if (const ExtractValueConstantExpr *EVCE =
+        dyn_cast<ExtractValueConstantExpr>(this))
+    return EVCE->Indices;
+
+  return cast<InsertValueConstantExpr>(this)->Indices;
+}
+
+unsigned ConstantExpr::getPredicate() const {
+  assert(isCompare());
+  return ((const CompareConstantExpr*)this)->predicate;
+}
+
+/// getWithOperandReplaced - Return a constant expression identical to this
+/// one, but with the specified operand set to the specified value.
+Constant *
+ConstantExpr::getWithOperandReplaced(unsigned OpNo, Constant *Op) const {
+  assert(Op->getType() == getOperand(OpNo)->getType() &&
+         "Replacing operand with value of different type!");
+  if (getOperand(OpNo) == Op)
+    return const_cast<ConstantExpr*>(this);
+
+  SmallVector<Constant*, 8> NewOps;
+  for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
+    NewOps.push_back(i == OpNo ? Op : getOperand(i));
+
+  return getWithOperands(NewOps);
+}
+
+/// getWithOperands - This returns the current constant expression with the
+/// 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, Type *Ty) const {
+  assert(Ops.size() == getNumOperands() && "Operand count mismatch!");
+  bool AnyChange = Ty != getType();
+  for (unsigned i = 0; i != Ops.size(); ++i)
+    AnyChange |= Ops[i] != getOperand(i);
+
+  if (!AnyChange)  // No operands changed, return self.
+    return const_cast<ConstantExpr*>(this);
+
+  switch (getOpcode()) {
+  case Instruction::Trunc:
+  case Instruction::ZExt:
+  case Instruction::SExt:
+  case Instruction::FPTrunc:
+  case Instruction::FPExt:
+  case Instruction::UIToFP:
+  case Instruction::SIToFP:
+  case Instruction::FPToUI:
+  case Instruction::FPToSI:
+  case Instruction::PtrToInt:
+  case Instruction::IntToPtr:
+  case Instruction::BitCast:
+    return ConstantExpr::getCast(getOpcode(), Ops[0], Ty);
+  case Instruction::Select:
+    return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]);
+  case Instruction::InsertElement:
+    return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]);
+  case Instruction::ExtractElement:
+    return ConstantExpr::getExtractElement(Ops[0], Ops[1]);
+  case Instruction::InsertValue:
+    return ConstantExpr::getInsertValue(Ops[0], Ops[1], getIndices());
+  case Instruction::ExtractValue:
+    return ConstantExpr::getExtractValue(Ops[0], getIndices());
+  case Instruction::ShuffleVector:
+    return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]);
+  case Instruction::GetElementPtr:
+    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]);
+  default:
+    assert(getNumOperands() == 2 && "Must be binary operator?");
+    return ConstantExpr::get(getOpcode(), Ops[0], Ops[1], SubclassOptionalData);
+  }
+}
+
+
+//===----------------------------------------------------------------------===//
+//                      isValueValidForType implementations
+
+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
+  uint64_t Max = (1ll << NumBits) - 1;
+  return Val <= Max;
+}
+
+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
+  int64_t Min = -(1ll << (NumBits-1));
+  int64_t Max = (1ll << (NumBits-1)) - 1;
+  return (Val >= Min && Val <= Max);
+}
+
+bool ConstantFP::isValueValidForType(Type *Ty, const APFloat& Val) {
+  // convert modifies in place, so make a copy.
+  APFloat Val2 = APFloat(Val);
+  bool losesInfo;
+  switch (Ty->getTypeID()) {
+  default:
+    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;
+    Val2.convert(APFloat::IEEEsingle, APFloat::rmNearestTiesToEven, &losesInfo);
+    return !losesInfo;
+  }
+  case Type::DoubleTyID: {
+    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::IEEEhalf ||
+           &Val2.getSemantics() == &APFloat::IEEEsingle || 
+           &Val2.getSemantics() == &APFloat::IEEEdouble ||
+           &Val2.getSemantics() == &APFloat::x87DoubleExtended;
+  case Type::FP128TyID:
+    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::IEEEhalf ||
+           &Val2.getSemantics() == &APFloat::IEEEsingle || 
+           &Val2.getSemantics() == &APFloat::IEEEdouble ||
+           &Val2.getSemantics() == &APFloat::PPCDoubleDouble;
+  }
+}
+
+
+//===----------------------------------------------------------------------===//
+//                      Factory Function Implementation
+
+ConstantAggregateZero *ConstantAggregateZero::get(Type *Ty) {
+  assert((Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy()) &&
+         "Cannot create an aggregate zero of non-aggregate type!");
+  
+  ConstantAggregateZero *&Entry = Ty->getContext().pImpl->CAZConstants[Ty];
+  if (Entry == 0)
+    Entry = new ConstantAggregateZero(Ty);
+
+  return Entry;
+}
+
+/// destroyConstant - Remove the constant from the constant table.
+///
+void ConstantAggregateZero::destroyConstant() {
+  getContext().pImpl->CAZConstants.erase(getType());
+  destroyConstantImpl();
+}
+
+/// destroyConstant - Remove the constant from the constant table...
+///
+void ConstantArray::destroyConstant() {
+  getType()->getContext().pImpl->ArrayConstants.remove(this);
+  destroyConstantImpl();
+}
+
+
+//---- ConstantStruct::get() implementation...
+//
+
+// destroyConstant - Remove the constant from the constant table...
+//
+void ConstantStruct::destroyConstant() {
+  getType()->getContext().pImpl->StructConstants.remove(this);
+  destroyConstantImpl();
+}
+
+// destroyConstant - Remove the constant from the constant table...
+//
+void ConstantVector::destroyConstant() {
+  getType()->getContext().pImpl->VectorConstants.remove(this);
+  destroyConstantImpl();
+}
+
+/// getSplatValue - If this is a splat vector constant, meaning that all of
+/// the elements have the same value, return that value. Otherwise return 0.
+Constant *Constant::getSplatValue() const {
+  assert(this->getType()->isVectorTy() && "Only valid for vectors!");
+  if (isa<ConstantAggregateZero>(this))
+    return getNullValue(this->getType()->getVectorElementType());
+  if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
+    return CV->getSplatValue();
+  if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
+    return CV->getSplatValue();
+  return 0;
+}
+
+/// 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 {
+  // Check out first element.
+  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;
+  return Elt;
+}
+
+/// If C is a constant integer then return its value, otherwise C must be a
+/// vector of constant integers, all equal, and the common value is returned.
+const APInt &Constant::getUniqueInteger() const {
+  if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
+    return CI->getValue();
+  assert(this->getSplatValue() && "Doesn't contain a unique integer!");
+  const Constant *C = this->getAggregateElement(0U);
+  assert(C && isa<ConstantInt>(C) && "Not a vector of numbers!");
+  return cast<ConstantInt>(C)->getValue();
+}
+
+
+//---- ConstantPointerNull::get() implementation.
+//
+
+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() {
+  getContext().pImpl->CPNConstants.erase(getType());
+  // Free the constant and any dangling references to it.
+  destroyConstantImpl();
+}
+
+
+//---- UndefValue::get() implementation.
+//
+
+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() {
+  // Free the constant and any dangling references to it.
+  getContext().pImpl->UVConstants.erase(getType());
+  destroyConstantImpl();
+}
+
+//---- BlockAddress::get() implementation.
+//
+
+BlockAddress *BlockAddress::get(BasicBlock *BB) {
+  assert(BB->getParent() != 0 && "Block must have a parent");
+  return get(BB->getParent(), BB);
+}
+
+BlockAddress *BlockAddress::get(Function *F, BasicBlock *BB) {
+  BlockAddress *&BA =
+    F->getContext().pImpl->BlockAddresses[std::make_pair(F, BB)];
+  if (BA == 0)
+    BA = new BlockAddress(F, BB);
+
+  assert(BA->getFunction() == F && "Basic block moved between functions");
+  return BA;
+}
+
+BlockAddress::BlockAddress(Function *F, BasicBlock *BB)
+: Constant(Type::getInt8PtrTy(F->getContext()), Value::BlockAddressVal,
+           &Op<0>(), 2) {
+  setOperand(0, F);
+  setOperand(1, BB);
+  BB->AdjustBlockAddressRefCount(1);
+}
+
+
+// destroyConstant - Remove the constant from the constant table.
+//
+void BlockAddress::destroyConstant() {
+  getFunction()->getType()->getContext().pImpl
+    ->BlockAddresses.erase(std::make_pair(getFunction(), getBasicBlock()));
+  getBasicBlock()->AdjustBlockAddressRefCount(-1);
+  destroyConstantImpl();
+}
+
+void BlockAddress::replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U) {
+  // This could be replacing either the Basic Block or the Function.  In either
+  // case, we have to remove the map entry.
+  Function *NewF = getFunction();
+  BasicBlock *NewBB = getBasicBlock();
+
+  if (U == &Op<0>())
+    NewF = cast<Function>(To);
+  else
+    NewBB = cast<BasicBlock>(To);
+
+  // See if the 'new' entry already exists, if not, just update this in place
+  // and return early.
+  BlockAddress *&NewBA =
+    getContext().pImpl->BlockAddresses[std::make_pair(NewF, NewBB)];
+  if (NewBA == 0) {
+    getBasicBlock()->AdjustBlockAddressRefCount(-1);
+
+    // Remove the old entry, this can't cause the map to rehash (just a
+    // tombstone will get added).
+    getContext().pImpl->BlockAddresses.erase(std::make_pair(getFunction(),
+                                                            getBasicBlock()));
+    NewBA = this;
+    setOperand(0, NewF);
+    setOperand(1, NewBB);
+    getBasicBlock()->AdjustBlockAddressRefCount(1);
+    return;
+  }
+
+  // Otherwise, I do need to replace this with an existing value.
+  assert(NewBA != this && "I didn't contain From!");
+
+  // Everyone using this now uses the replacement.
+  replaceAllUsesWith(NewBA);
+
+  destroyConstant();
+}
+
+//---- ConstantExpr::get() implementations.
+//
+
+/// 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, Type *Ty) {
+  assert(Ty->isFirstClassType() && "Cannot cast to an aggregate type!");
+  // Fold a few common cases
+  if (Constant *FC = ConstantFoldCastInstruction(opc, C, Ty))
+    return FC;
+
+  LLVMContextImpl *pImpl = Ty->getContext().pImpl;
+
+  // Look up the constant in the table first to ensure uniqueness.
+  ExprMapKeyType Key(opc, C);
+
+  return pImpl->ExprConstants.getOrCreate(Ty, Key);
+}
+
+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");
+  assert(CastInst::castIsValid(opc, C, Ty) && "Invalid constantexpr cast!");
+
+  switch (opc) {
+  default:
+    llvm_unreachable("Invalid cast opcode");
+  case Instruction::Trunc:    return getTrunc(C, Ty);
+  case Instruction::ZExt:     return getZExt(C, Ty);
+  case Instruction::SExt:     return getSExt(C, Ty);
+  case Instruction::FPTrunc:  return getFPTrunc(C, Ty);
+  case Instruction::FPExt:    return getFPExtend(C, Ty);
+  case Instruction::UIToFP:   return getUIToFP(C, Ty);
+  case Instruction::SIToFP:   return getSIToFP(C, Ty);
+  case Instruction::FPToUI:   return getFPToUI(C, Ty);
+  case Instruction::FPToSI:   return getFPToSI(C, Ty);
+  case Instruction::PtrToInt: return getPtrToInt(C, Ty);
+  case Instruction::IntToPtr: return getIntToPtr(C, Ty);
+  case Instruction::BitCast:  return getBitCast(C, 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, Type *Ty) {
+  if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
+    return getBitCast(C, Ty);
+  return getSExt(C, 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, Type *Ty) {
+  assert(S->getType()->isPtrOrPtrVectorTy() && "Invalid cast");
+  assert((Ty->isIntOrIntVectorTy() || Ty->isPtrOrPtrVectorTy()) &&
+          "Invalid cast");
+
+  if (Ty->isIntOrIntVectorTy())
+    return getPtrToInt(S, Ty);
+  return getBitCast(S, Ty);
+}
+
+Constant *ConstantExpr::getIntegerCast(Constant *C, Type *Ty, 
+                                       bool isSigned) {
+  assert(C->getType()->isIntOrIntVectorTy() &&
+         Ty->isIntOrIntVectorTy() && "Invalid cast");
+  unsigned SrcBits = C->getType()->getScalarSizeInBits();
+  unsigned DstBits = Ty->getScalarSizeInBits();
+  Instruction::CastOps opcode =
+    (SrcBits == DstBits ? Instruction::BitCast :
+     (SrcBits > DstBits ? Instruction::Trunc :
+      (isSigned ? Instruction::SExt : Instruction::ZExt)));
+  return getCast(opcode, C, Ty);
+}
+
+Constant *ConstantExpr::getFPCast(Constant *C, Type *Ty) {
+  assert(C->getType()->isFPOrFPVectorTy() && Ty->isFPOrFPVectorTy() &&
+         "Invalid cast");
+  unsigned SrcBits = C->getType()->getScalarSizeInBits();
+  unsigned DstBits = Ty->getScalarSizeInBits();
+  if (SrcBits == DstBits)
+    return C; // Avoid a useless cast
+  Instruction::CastOps opcode =
+    (SrcBits > DstBits ? Instruction::FPTrunc : Instruction::FPExt);
+  return getCast(opcode, C, Ty);
+}
+
+Constant *ConstantExpr::getTrunc(Constant *C, Type *Ty) {
+#ifndef NDEBUG
+  bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
+  bool toVec = Ty->getTypeID() == Type::VectorTyID;
+#endif
+  assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
+  assert(C->getType()->isIntOrIntVectorTy() && "Trunc operand must be integer");
+  assert(Ty->isIntOrIntVectorTy() && "Trunc produces only integral");
+  assert(C->getType()->getScalarSizeInBits() > Ty->getScalarSizeInBits()&&
+         "SrcTy must be larger than DestTy for Trunc!");
+
+  return getFoldedCast(Instruction::Trunc, C, Ty);
+}
+
+Constant *ConstantExpr::getSExt(Constant *C, Type *Ty) {
+#ifndef NDEBUG
+  bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
+  bool toVec = Ty->getTypeID() == Type::VectorTyID;
+#endif
+  assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
+  assert(C->getType()->isIntOrIntVectorTy() && "SExt operand must be integral");
+  assert(Ty->isIntOrIntVectorTy() && "SExt produces only integer");
+  assert(C->getType()->getScalarSizeInBits() < Ty->getScalarSizeInBits()&&
+         "SrcTy must be smaller than DestTy for SExt!");
+
+  return getFoldedCast(Instruction::SExt, C, Ty);
+}
+
+Constant *ConstantExpr::getZExt(Constant *C, Type *Ty) {
+#ifndef NDEBUG
+  bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
+  bool toVec = Ty->getTypeID() == Type::VectorTyID;
+#endif
+  assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
+  assert(C->getType()->isIntOrIntVectorTy() && "ZEXt operand must be integral");
+  assert(Ty->isIntOrIntVectorTy() && "ZExt produces only integer");
+  assert(C->getType()->getScalarSizeInBits() < Ty->getScalarSizeInBits()&&
+         "SrcTy must be smaller than DestTy for ZExt!");
+
+  return getFoldedCast(Instruction::ZExt, C, Ty);
+}
+
+Constant *ConstantExpr::getFPTrunc(Constant *C, Type *Ty) {
+#ifndef NDEBUG
+  bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
+  bool toVec = Ty->getTypeID() == Type::VectorTyID;
+#endif
+  assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
+  assert(C->getType()->isFPOrFPVectorTy() && Ty->isFPOrFPVectorTy() &&
+         C->getType()->getScalarSizeInBits() > Ty->getScalarSizeInBits()&&
+         "This is an illegal floating point truncation!");
+  return getFoldedCast(Instruction::FPTrunc, C, Ty);
+}
+
+Constant *ConstantExpr::getFPExtend(Constant *C, Type *Ty) {
+#ifndef NDEBUG
+  bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
+  bool toVec = Ty->getTypeID() == Type::VectorTyID;
+#endif
+  assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
+  assert(C->getType()->isFPOrFPVectorTy() && Ty->isFPOrFPVectorTy() &&
+         C->getType()->getScalarSizeInBits() < Ty->getScalarSizeInBits()&&
+         "This is an illegal floating point extension!");
+  return getFoldedCast(Instruction::FPExt, C, Ty);
+}
+
+Constant *ConstantExpr::getUIToFP(Constant *C, Type *Ty) {
+#ifndef NDEBUG
+  bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
+  bool toVec = Ty->getTypeID() == Type::VectorTyID;
+#endif
+  assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
+  assert(C->getType()->isIntOrIntVectorTy() && Ty->isFPOrFPVectorTy() &&
+         "This is an illegal uint to floating point cast!");
+  return getFoldedCast(Instruction::UIToFP, C, Ty);
+}
+
+Constant *ConstantExpr::getSIToFP(Constant *C, Type *Ty) {
+#ifndef NDEBUG
+  bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
+  bool toVec = Ty->getTypeID() == Type::VectorTyID;
+#endif
+  assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
+  assert(C->getType()->isIntOrIntVectorTy() && Ty->isFPOrFPVectorTy() &&
+         "This is an illegal sint to floating point cast!");
+  return getFoldedCast(Instruction::SIToFP, C, Ty);
+}
+
+Constant *ConstantExpr::getFPToUI(Constant *C, Type *Ty) {
+#ifndef NDEBUG
+  bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
+  bool toVec = Ty->getTypeID() == Type::VectorTyID;
+#endif
+  assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
+  assert(C->getType()->isFPOrFPVectorTy() && Ty->isIntOrIntVectorTy() &&
+         "This is an illegal floating point to uint cast!");
+  return getFoldedCast(Instruction::FPToUI, C, Ty);
+}
+
+Constant *ConstantExpr::getFPToSI(Constant *C, Type *Ty) {
+#ifndef NDEBUG
+  bool fromVec = C->getType()->getTypeID() == Type::VectorTyID;
+  bool toVec = Ty->getTypeID() == Type::VectorTyID;
+#endif
+  assert((fromVec == toVec) && "Cannot convert from scalar to/from vector");
+  assert(C->getType()->isFPOrFPVectorTy() && Ty->isIntOrIntVectorTy() &&
+         "This is an illegal floating point to sint cast!");
+  return getFoldedCast(Instruction::FPToSI, C, Ty);
+}
+
+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, 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, Type *DstTy) {
+  assert(CastInst::castIsValid(Instruction::BitCast, C, DstTy) &&
+         "Invalid constantexpr bitcast!");
+
+  // It is common to ask for a bitcast of a value to its own type, handle this
+  // speedily.
+  if (C->getType() == DstTy) return C;
+
+  return getFoldedCast(Instruction::BitCast, C, DstTy);
+}
+
+Constant *ConstantExpr::get(unsigned Opcode, Constant *C1, Constant *C2,
+                            unsigned Flags) {
+  // Check the operands for consistency first.
+  assert(Opcode >= Instruction::BinaryOpsBegin &&
+         Opcode <  Instruction::BinaryOpsEnd   &&
+         "Invalid opcode in binary constant expression");
+  assert(C1->getType() == C2->getType() &&
+         "Operand types in binary constant expression should match");
+
+#ifndef NDEBUG
+  switch (Opcode) {
+  case Instruction::Add:
+  case Instruction::Sub:
+  case Instruction::Mul:
+    assert(C1->getType() == C2->getType() && "Op types should be identical!");
+    assert(C1->getType()->isIntOrIntVectorTy() &&
+           "Tried to create an integer operation on a non-integer type!");
+    break;
+  case Instruction::FAdd:
+  case Instruction::FSub:
+  case Instruction::FMul:
+    assert(C1->getType() == C2->getType() && "Op types should be identical!");
+    assert(C1->getType()->isFPOrFPVectorTy() &&
+           "Tried to create a floating-point operation on a "
+           "non-floating-point type!");
+    break;
+  case Instruction::UDiv: 
+  case Instruction::SDiv: 
+    assert(C1->getType() == C2->getType() && "Op types should be identical!");
+    assert(C1->getType()->isIntOrIntVectorTy() &&
+           "Tried to create an arithmetic operation on a non-arithmetic type!");
+    break;
+  case Instruction::FDiv:
+    assert(C1->getType() == C2->getType() && "Op types should be identical!");
+    assert(C1->getType()->isFPOrFPVectorTy() &&
+           "Tried to create an arithmetic operation on a non-arithmetic type!");
+    break;
+  case Instruction::URem: 
+  case Instruction::SRem: 
+    assert(C1->getType() == C2->getType() && "Op types should be identical!");
+    assert(C1->getType()->isIntOrIntVectorTy() &&
+           "Tried to create an arithmetic operation on a non-arithmetic type!");
+    break;
+  case Instruction::FRem:
+    assert(C1->getType() == C2->getType() && "Op types should be identical!");
+    assert(C1->getType()->isFPOrFPVectorTy() &&
+           "Tried to create an arithmetic operation on a non-arithmetic type!");
+    break;
+  case Instruction::And:
+  case Instruction::Or:
+  case Instruction::Xor:
+    assert(C1->getType() == C2->getType() && "Op types should be identical!");
+    assert(C1->getType()->isIntOrIntVectorTy() &&
+           "Tried to create a logical operation on a non-integral type!");
+    break;
+  case Instruction::Shl:
+  case Instruction::LShr:
+  case Instruction::AShr:
+    assert(C1->getType() == C2->getType() && "Op types should be identical!");
+    assert(C1->getType()->isIntOrIntVectorTy() &&
+           "Tried to create a shift operation on a non-integer type!");
+    break;
+  default:
+    break;
+  }
+#endif
+
+  if (Constant *FC = ConstantFoldBinaryInstruction(Opcode, C1, C2))
+    return FC;          // Fold a few common cases.
+
+  Constant *ArgVec[] = { C1, C2 };
+  ExprMapKeyType Key(Opcode, ArgVec, 0, Flags);
+
+  LLVMContextImpl *pImpl = C1->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(C1->getType(), Key);
+}
+
+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);
+  return getPtrToInt(GEP, 
+                     Type::getInt64Ty(Ty->getContext()));
+}
+
+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.
+  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);
+  return getPtrToInt(GEP,
+                     Type::getInt64Ty(Ty->getContext()));
+}
+
+Constant *ConstantExpr::getOffsetOf(StructType* STy, unsigned FieldNo) {
+  return getOffsetOf(STy, ConstantInt::get(Type::getInt32Ty(STy->getContext()),
+                                           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[] = {
+    ConstantInt::get(Type::getInt64Ty(Ty->getContext()), 0),
+    FieldNo
+  };
+  Constant *GEP = getGetElementPtr(
+                Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx);
+  return getPtrToInt(GEP,
+                     Type::getInt64Ty(Ty->getContext()));
+}
+
+Constant *ConstantExpr::getCompare(unsigned short Predicate, 
+                                   Constant *C1, Constant *C2) {
+  assert(C1->getType() == C2->getType() && "Op types should be identical!");
+
+  switch (Predicate) {
+  default: llvm_unreachable("Invalid CmpInst predicate");
+  case CmpInst::FCMP_FALSE: case CmpInst::FCMP_OEQ: case CmpInst::FCMP_OGT:
+  case CmpInst::FCMP_OGE:   case CmpInst::FCMP_OLT: case CmpInst::FCMP_OLE:
+  case CmpInst::FCMP_ONE:   case CmpInst::FCMP_ORD: case CmpInst::FCMP_UNO:
+  case CmpInst::FCMP_UEQ:   case CmpInst::FCMP_UGT: case CmpInst::FCMP_UGE:
+  case CmpInst::FCMP_ULT:   case CmpInst::FCMP_ULE: case CmpInst::FCMP_UNE:
+  case CmpInst::FCMP_TRUE:
+    return getFCmp(Predicate, C1, C2);
+
+  case CmpInst::ICMP_EQ:  case CmpInst::ICMP_NE:  case CmpInst::ICMP_UGT:
+  case CmpInst::ICMP_UGE: case CmpInst::ICMP_ULT: case CmpInst::ICMP_ULE:
+  case CmpInst::ICMP_SGT: case CmpInst::ICMP_SGE: case CmpInst::ICMP_SLT:
+  case CmpInst::ICMP_SLE:
+    return getICmp(Predicate, C1, C2);
+  }
+}
+
+Constant *ConstantExpr::getSelect(Constant *C, Constant *V1, Constant *V2) {
+  assert(!SelectInst::areInvalidOperands(C, V1, V2)&&"Invalid select operands");
+
+  if (Constant *SC = ConstantFoldSelectInstruction(C, V1, V2))
+    return SC;        // Fold common cases
+
+  Constant *ArgVec[] = { C, V1, V2 };
+  ExprMapKeyType Key(Instruction::Select, ArgVec);
+
+  LLVMContextImpl *pImpl = C->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(V1->getType(), Key);
+}
+
+Constant *ConstantExpr::getGetElementPtr(Constant *C, ArrayRef<Value *> Idxs,
+                                         bool InBounds) {
+  assert(C->getType()->isPtrOrPtrVectorTy() &&
+         "Non-pointer type for constant GetElementPtr expression");
+
+  if (Constant *FC = ConstantFoldGetElementPtr(C, InBounds, Idxs))
+    return FC;          // Fold a few common cases.
+
+  // Get the result type of the getelementptr!
+  Type *Ty = GetElementPtrInst::getIndexedType(C->getType(), Idxs);
+  assert(Ty && "GEP indices invalid!");
+  unsigned AS = C->getType()->getPointerAddressSpace();
+  Type *ReqTy = Ty->getPointerTo(AS);
+  if (VectorType *VecTy = dyn_cast<VectorType>(C->getType()))
+    ReqTy = VectorType::get(ReqTy, VecTy->getNumElements());
+
+  // Look up the constant in the table first to ensure uniqueness
+  std::vector<Constant*> ArgVec;
+  ArgVec.reserve(1 + Idxs.size());
+  ArgVec.push_back(C);
+  for (unsigned i = 0, e = Idxs.size(); i != e; ++i) {
+    assert(Idxs[i]->getType()->isVectorTy() == ReqTy->isVectorTy() &&
+           "getelementptr index type missmatch");
+    assert((!Idxs[i]->getType()->isVectorTy() ||
+            ReqTy->getVectorNumElements() ==
+            Idxs[i]->getType()->getVectorNumElements()) &&
+           "getelementptr index type missmatch");
+    ArgVec.push_back(cast<Constant>(Idxs[i]));
+  }
+  const ExprMapKeyType Key(Instruction::GetElementPtr, ArgVec, 0,
+                           InBounds ? GEPOperator::IsInBounds : 0);
+
+  LLVMContextImpl *pImpl = C->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
+}
+
+Constant *
+ConstantExpr::getICmp(unsigned short pred, Constant *LHS, Constant *RHS) {
+  assert(LHS->getType() == RHS->getType());
+  assert(pred >= ICmpInst::FIRST_ICMP_PREDICATE && 
+         pred <= ICmpInst::LAST_ICMP_PREDICATE && "Invalid ICmp Predicate");
+
+  if (Constant *FC = ConstantFoldCompareInstruction(pred, LHS, RHS))
+    return FC;          // Fold a few common cases...
+
+  // Look up the constant in the table first to ensure uniqueness
+  Constant *ArgVec[] = { LHS, RHS };
+  // Get the key type with both the opcode and predicate
+  const ExprMapKeyType Key(Instruction::ICmp, ArgVec, pred);
+
+  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;
+  return pImpl->ExprConstants.getOrCreate(ResultTy, Key);
+}
+
+Constant *
+ConstantExpr::getFCmp(unsigned short pred, Constant *LHS, Constant *RHS) {
+  assert(LHS->getType() == RHS->getType());
+  assert(pred <= FCmpInst::LAST_FCMP_PREDICATE && "Invalid FCmp Predicate");
+
+  if (Constant *FC = ConstantFoldCompareInstruction(pred, LHS, RHS))
+    return FC;          // Fold a few common cases...
+
+  // Look up the constant in the table first to ensure uniqueness
+  Constant *ArgVec[] = { LHS, RHS };
+  // Get the key type with both the opcode and predicate
+  const ExprMapKeyType Key(Instruction::FCmp, ArgVec, pred);
+
+  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;
+  return pImpl->ExprConstants.getOrCreate(ResultTy, Key);
+}
+
+Constant *ConstantExpr::getExtractElement(Constant *Val, Constant *Idx) {
+  assert(Val->getType()->isVectorTy() &&
+         "Tried to create extractelement operation on non-vector type!");
+  assert(Idx->getType()->isIntegerTy(32) &&
+         "Extractelement index must be i32 type!");
+
+  if (Constant *FC = ConstantFoldExtractElementInstruction(Val, Idx))
+    return FC;          // Fold a few common cases.
+
+  // Look up the constant in the table first to ensure uniqueness
+  Constant *ArgVec[] = { Val, Idx };
+  const ExprMapKeyType Key(Instruction::ExtractElement, ArgVec);
+
+  LLVMContextImpl *pImpl = Val->getContext().pImpl;
+  Type *ReqTy = Val->getType()->getVectorElementType();
+  return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
+}
+
+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() == Val->getType()->getVectorElementType() &&
+         "Insertelement types must match!");
+  assert(Idx->getType()->isIntegerTy(32) &&
+         "Insertelement index must be i32 type!");
+
+  if (Constant *FC = ConstantFoldInsertElementInstruction(Val, Elt, Idx))
+    return FC;          // Fold a few common cases.
+  // Look up the constant in the table first to ensure uniqueness
+  Constant *ArgVec[] = { Val, Elt, Idx };
+  const ExprMapKeyType Key(Instruction::InsertElement, ArgVec);
+
+  LLVMContextImpl *pImpl = Val->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(Val->getType(), Key);
+}
+
+Constant *ConstantExpr::getShuffleVector(Constant *V1, Constant *V2, 
+                                         Constant *Mask) {
+  assert(ShuffleVectorInst::isValidOperands(V1, V2, Mask) &&
+         "Invalid shuffle vector constant expr operands!");
+
+  if (Constant *FC = ConstantFoldShuffleVectorInstruction(V1, V2, Mask))
+    return FC;          // Fold a few common cases.
+
+  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
+  Constant *ArgVec[] = { V1, V2, Mask };
+  const ExprMapKeyType Key(Instruction::ShuffleVector, ArgVec);
+
+  LLVMContextImpl *pImpl = ShufTy->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(ShufTy, Key);
+}
+
+Constant *ConstantExpr::getInsertValue(Constant *Agg, Constant *Val,
+                                       ArrayRef<unsigned> Idxs) {
+  assert(ExtractValueInst::getIndexedType(Agg->getType(),
+                                          Idxs) == Val->getType() &&
+         "insertvalue indices invalid!");
+  assert(Agg->getType()->isFirstClassType() &&
+         "Non-first-class type for constant insertvalue expression");
+  Constant *FC = ConstantFoldInsertValueInstruction(Agg, Val, Idxs);
+  assert(FC && "insertvalue constant expr couldn't be folded!");
+  return FC;
+}
+
+Constant *ConstantExpr::getExtractValue(Constant *Agg,
+                                        ArrayRef<unsigned> Idxs) {
+  assert(Agg->getType()->isFirstClassType() &&
+         "Tried to create extractelement operation on non-first-class type!");
+
+  Type *ReqTy = ExtractValueInst::getIndexedType(Agg->getType(), Idxs);
+  (void)ReqTy;
+  assert(ReqTy && "extractvalue indices invalid!");
+
+  assert(Agg->getType()->isFirstClassType() &&
+         "Non-first-class type for constant extractvalue expression");
+  Constant *FC = ConstantFoldExtractValueInstruction(Agg, Idxs);
+  assert(FC && "ExtractValue constant expr couldn't be folded!");
+  return FC;
+}
+
+Constant *ConstantExpr::getNeg(Constant *C, bool HasNUW, bool HasNSW) {
+  assert(C->getType()->isIntOrIntVectorTy() &&
+         "Cannot NEG a nonintegral value!");
+  return getSub(ConstantFP::getZeroValueForNegation(C->getType()),
+                C, HasNUW, HasNSW);
+}
+
+Constant *ConstantExpr::getFNeg(Constant *C) {
+  assert(C->getType()->isFPOrFPVectorTy() &&
+         "Cannot FNEG a non-floating-point value!");
+  return getFSub(ConstantFP::getZeroValueForNegation(C->getType()), C);
+}
+
+Constant *ConstantExpr::getNot(Constant *C) {
+  assert(C->getType()->isIntOrIntVectorTy() &&
+         "Cannot NOT a nonintegral value!");
+  return get(Instruction::Xor, C, Constant::getAllOnesValue(C->getType()));
+}
+
+Constant *ConstantExpr::getAdd(Constant *C1, Constant *C2,
+                               bool HasNUW, bool HasNSW) {
+  unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
+                   (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
+  return get(Instruction::Add, C1, C2, Flags);
+}
+
+Constant *ConstantExpr::getFAdd(Constant *C1, Constant *C2) {
+  return get(Instruction::FAdd, C1, C2);
+}
+
+Constant *ConstantExpr::getSub(Constant *C1, Constant *C2,
+                               bool HasNUW, bool HasNSW) {
+  unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
+                   (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
+  return get(Instruction::Sub, C1, C2, Flags);
+}
+
+Constant *ConstantExpr::getFSub(Constant *C1, Constant *C2) {
+  return get(Instruction::FSub, C1, C2);
+}
+
+Constant *ConstantExpr::getMul(Constant *C1, Constant *C2,
+                               bool HasNUW, bool HasNSW) {
+  unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
+                   (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
+  return get(Instruction::Mul, C1, C2, Flags);
+}
+
+Constant *ConstantExpr::getFMul(Constant *C1, Constant *C2) {
+  return get(Instruction::FMul, C1, C2);
+}
+
+Constant *ConstantExpr::getUDiv(Constant *C1, Constant *C2, bool isExact) {
+  return get(Instruction::UDiv, C1, C2,
+             isExact ? PossiblyExactOperator::IsExact : 0);
+}
+
+Constant *ConstantExpr::getSDiv(Constant *C1, Constant *C2, bool isExact) {
+  return get(Instruction::SDiv, C1, C2,
+             isExact ? PossiblyExactOperator::IsExact : 0);
+}
+
+Constant *ConstantExpr::getFDiv(Constant *C1, Constant *C2) {
+  return get(Instruction::FDiv, C1, C2);
+}
+
+Constant *ConstantExpr::getURem(Constant *C1, Constant *C2) {
+  return get(Instruction::URem, C1, C2);
+}
+
+Constant *ConstantExpr::getSRem(Constant *C1, Constant *C2) {
+  return get(Instruction::SRem, C1, C2);
+}
+
+Constant *ConstantExpr::getFRem(Constant *C1, Constant *C2) {
+  return get(Instruction::FRem, C1, C2);
+}
+
+Constant *ConstantExpr::getAnd(Constant *C1, Constant *C2) {
+  return get(Instruction::And, C1, C2);
+}
+
+Constant *ConstantExpr::getOr(Constant *C1, Constant *C2) {
+  return get(Instruction::Or, C1, C2);
+}
+
+Constant *ConstantExpr::getXor(Constant *C1, Constant *C2) {
+  return get(Instruction::Xor, C1, C2);
+}
+
+Constant *ConstantExpr::getShl(Constant *C1, Constant *C2,
+                               bool HasNUW, bool HasNSW) {
+  unsigned Flags = (HasNUW ? OverflowingBinaryOperator::NoUnsignedWrap : 0) |
+                   (HasNSW ? OverflowingBinaryOperator::NoSignedWrap   : 0);
+  return get(Instruction::Shl, C1, C2, Flags);
+}
+
+Constant *ConstantExpr::getLShr(Constant *C1, Constant *C2, bool isExact) {
+  return get(Instruction::LShr, C1, C2,
+             isExact ? PossiblyExactOperator::IsExact : 0);
+}
+
+Constant *ConstantExpr::getAShr(Constant *C1, Constant *C2, bool isExact) {
+  return get(Instruction::AShr, C1, C2,
+             isExact ? PossiblyExactOperator::IsExact : 0);
+}
+
+/// getBinOpIdentity - Return the identity for the given binary operation,
+/// i.e. a constant C such that X op C = X and C op X = X for every X.  It
+/// returns null if the operator doesn't have an identity.
+Constant *ConstantExpr::getBinOpIdentity(unsigned Opcode, Type *Ty) {
+  switch (Opcode) {
+  default:
+    // Doesn't have an identity.
+    return 0;
+
+  case Instruction::Add:
+  case Instruction::Or:
+  case Instruction::Xor:
+    return Constant::getNullValue(Ty);
+
+  case Instruction::Mul:
+    return ConstantInt::get(Ty, 1);
+
+  case Instruction::And:
+    return Constant::getAllOnesValue(Ty);
+  }
+}
+
+/// getBinOpAbsorber - Return the absorbing element for the given binary
+/// operation, i.e. a constant C such that X op C = C and C op X = C for
+/// every X.  For example, this returns zero for integer multiplication.
+/// It returns null if the operator doesn't have an absorbing element.
+Constant *ConstantExpr::getBinOpAbsorber(unsigned Opcode, Type *Ty) {
+  switch (Opcode) {
+  default:
+    // Doesn't have an absorber.
+    return 0;
+
+  case Instruction::Or:
+    return Constant::getAllOnesValue(Ty);
+
+  case Instruction::And:
+  case Instruction::Mul:
+    return Constant::getNullValue(Ty);
+  }
+}
+
+// destroyConstant - Remove the constant from the constant table...
+//
+void ConstantExpr::destroyConstant() {
+  getType()->getContext().pImpl->ExprConstants.remove(this);
+  destroyConstantImpl();
+}
+
+const char *ConstantExpr::getOpcodeName() const {
+  return Instruction::getOpcodeName(getOpcode());
+}
+
+
+
+GetElementPtrConstantExpr::
+GetElementPtrConstantExpr(Constant *C, ArrayRef<Constant*> IdxList,
+                          Type *DestTy)
+  : ConstantExpr(DestTy, Instruction::GetElementPtr,
+                 OperandTraits<GetElementPtrConstantExpr>::op_end(this)
+                 - (IdxList.size()+1), IdxList.size()+1) {
+  OperandList[0] = C;
+  for (unsigned i = 0, E = IdxList.size(); i != E; ++i)
+    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 a 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());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*1), Ty);
+}
+Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<uint16_t> Elts){
+  Type *Ty = ArrayType::get(Type::getInt16Ty(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*2), Ty);
+}
+Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<uint32_t> Elts){
+  Type *Ty = ArrayType::get(Type::getInt32Ty(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*4), Ty);
+}
+Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<uint64_t> Elts){
+  Type *Ty = ArrayType::get(Type::getInt64Ty(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*8), Ty);
+}
+Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<float> Elts) {
+  Type *Ty = ArrayType::get(Type::getFloatTy(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*4), Ty);
+}
+Constant *ConstantDataArray::get(LLVMContext &Context, ArrayRef<double> Elts) {
+  Type *Ty = ArrayType::get(Type::getDoubleTy(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(const_cast<char *>(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) {
+    const uint8_t *Data = reinterpret_cast<const uint8_t *>(Str.data());
+    return get(Context, ArrayRef<uint8_t>(const_cast<uint8_t *>(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());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*1), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint16_t> Elts){
+  Type *Ty = VectorType::get(Type::getInt16Ty(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*2), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint32_t> Elts){
+  Type *Ty = VectorType::get(Type::getInt32Ty(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*4), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint64_t> Elts){
+  Type *Ty = VectorType::get(Type::getInt64Ty(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*8), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<float> Elts) {
+  Type *Ty = VectorType::get(Type::getFloatTy(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(const_cast<char *>(Data), Elts.size()*4), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<double> Elts) {
+  Type *Ty = VectorType::get(Type::getDoubleTy(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(const_cast<char *>(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);
+  }
+
+  if (ConstantFP *CFP = dyn_cast<ConstantFP>(V)) {
+    if (CFP->getType()->isFloatTy()) {
+      SmallVector<float, 16> Elts(NumElts, CFP->getValueAPF().convertToFloat());
+      return get(V->getContext(), Elts);
+    }
+    if (CFP->getType()->isDoubleTy()) {
+      SmallVector<double, 16> Elts(NumElts,
+                                   CFP->getValueAPF().convertToDouble());
+      return get(V->getContext(), Elts);
+    }
+  }
+  return ConstantVector::getSplat(NumElts, V);
+}
+
+
+/// 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: llvm_unreachable("Invalid bitwidth for CDS");
+  case 8:
+    return *const_cast<uint8_t *>(reinterpret_cast<const uint8_t *>(EltPtr));
+  case 16:
+    return *const_cast<uint16_t *>(reinterpret_cast<const uint16_t *>(EltPtr));
+  case 32:
+    return *const_cast<uint32_t *>(reinterpret_cast<const uint32_t *>(EltPtr));
+  case 64:
+    return *const_cast<uint64_t *>(reinterpret_cast<const 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:
+    llvm_unreachable("Accessor can only be used when element is float/double!");
+  case Type::FloatTyID: {
+      const float *FloatPrt = reinterpret_cast<const float *>(EltPtr);
+      return APFloat(*const_cast<float *>(FloatPrt));
+    }
+  case Type::DoubleTyID: {
+      const double *DoublePtr = reinterpret_cast<const double *>(EltPtr);
+      return APFloat(*const_cast<double *>(DoublePtr));
+    }
+  }
+}
+
+/// 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'");
+  const float *EltPtr = reinterpret_cast<const float *>(getElementPointer(Elt));
+  return *const_cast<float *>(EltPtr);
+}
+
+/// 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'");
+  const double *EltPtr =
+      reinterpret_cast<const double *>(getElementPointer(Elt));
+  return *const_cast<double *>(EltPtr);
+}
+
+/// 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
+
+/// replaceUsesOfWithOnConstant - Update this constant array to change uses of
+/// 'From' to be uses of 'To'.  This must update the uniquing data structures
+/// etc.
+///
+/// Note that we intentionally replace all uses of From with To here.  Consider
+/// a large array that uses 'From' 1000 times.  By handling this case all here,
+/// ConstantArray::replaceUsesOfWithOnConstant is only invoked once, and that
+/// single invocation handles all 1000 uses.  Handling them one at a time would
+/// work, but would be really slow because it would have to unique each updated
+/// array instance.
+///
+void ConstantArray::replaceUsesOfWithOnConstant(Value *From, Value *To,
+                                                Use *U) {
+  assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
+  Constant *ToC = cast<Constant>(To);
+
+  LLVMContextImpl *pImpl = getType()->getContext().pImpl;
+
+  SmallVector<Constant*, 8> Values;
+  LLVMContextImpl::ArrayConstantsTy::LookupKey Lookup;
+  Lookup.first = cast<ArrayType>(getType());
+  Values.reserve(getNumOperands());  // Build replacement array.
+
+  // Fill values with the modified operands of the constant array.  Also,
+  // compute whether this turns into an all-zeros array.
+  unsigned NumUpdated = 0;
+
+  // 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 (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.
+    Lookup.second = makeArrayRef(Values);
+    LLVMContextImpl::ArrayConstantsTy::MapTy::iterator I =
+      pImpl->ArrayConstants.find(Lookup);
+
+    if (I != pImpl->ArrayConstants.map_end()) {
+      Replacement = I->first;
+    } else {
+      // Okay, the new shape doesn't exist in the system yet.  Instead of
+      // creating a new constant array, inserting it, replaceallusesof'ing the
+      // old with the new, then deleting the old... just update the current one
+      // in place!
+      pImpl->ArrayConstants.remove(this);
+
+      // Update to the new value.  Optimize for the case when we have a single
+      // operand that we're changing, but handle bulk updates efficiently.
+      if (NumUpdated == 1) {
+        unsigned OperandToUpdate = U - OperandList;
+        assert(getOperand(OperandToUpdate) == From &&
+               "ReplaceAllUsesWith broken!");
+        setOperand(OperandToUpdate, ToC);
+      } else {
+        for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
+          if (getOperand(i) == From)
+            setOperand(i, ToC);
+      }
+      pImpl->ArrayConstants.insert(this);
+      return;
+    }
+  }
+
+  // Otherwise, I do need to replace this with an existing value.
+  assert(Replacement != this && "I didn't contain From!");
+
+  // Everyone using this now uses the replacement.
+  replaceAllUsesWith(Replacement);
+
+  // Delete the old constant!
+  destroyConstant();
+}
+
+void ConstantStruct::replaceUsesOfWithOnConstant(Value *From, Value *To,
+                                                 Use *U) {
+  assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
+  Constant *ToC = cast<Constant>(To);
+
+  unsigned OperandToUpdate = U-OperandList;
+  assert(getOperand(OperandToUpdate) == From && "ReplaceAllUsesWith broken!");
+
+  SmallVector<Constant*, 8> Values;
+  LLVMContextImpl::StructConstantsTy::LookupKey Lookup;
+  Lookup.first = cast<StructType>(getType());
+  Values.reserve(getNumOperands());  // Build replacement struct.
+
+  // Fill values with the modified operands of the constant struct.  Also,
+  // compute whether this turns into an all-zeros struct.
+  bool isAllZeros = false;
+  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;
+
+  LLVMContextImpl *pImpl = getContext().pImpl;
+
+  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.
+    Lookup.second = makeArrayRef(Values);
+    LLVMContextImpl::StructConstantsTy::MapTy::iterator I =
+      pImpl->StructConstants.find(Lookup);
+
+    if (I != pImpl->StructConstants.map_end()) {
+      Replacement = I->first;
+    } else {
+      // Okay, the new shape doesn't exist in the system yet.  Instead of
+      // creating a new constant struct, inserting it, replaceallusesof'ing the
+      // old with the new, then deleting the old... just update the current one
+      // in place!
+      pImpl->StructConstants.remove(this);
+
+      // Update to the new value.
+      setOperand(OperandToUpdate, ToC);
+      pImpl->StructConstants.insert(this);
+      return;
+    }
+  }
+
+  assert(Replacement != this && "I didn't contain From!");
+
+  // Everyone using this now uses the replacement.
+  replaceAllUsesWith(Replacement);
+
+  // Delete the old constant!
+  destroyConstant();
+}
+
+void ConstantVector::replaceUsesOfWithOnConstant(Value *From, Value *To,
+                                                 Use *U) {
+  assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
+
+  SmallVector<Constant*, 8> Values;
+  Values.reserve(getNumOperands());  // Build replacement array...
+  for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
+    Constant *Val = getOperand(i);
+    if (Val == From) Val = cast<Constant>(To);
+    Values.push_back(Val);
+  }
+
+  Constant *Replacement = get(Values);
+  assert(Replacement != this && "I didn't contain From!");
+
+  // Everyone using this now uses the replacement.
+  replaceAllUsesWith(Replacement);
+
+  // Delete the old constant!
+  destroyConstant();
+}
+
+void ConstantExpr::replaceUsesOfWithOnConstant(Value *From, Value *ToV,
+                                               Use *U) {
+  assert(isa<Constant>(ToV) && "Cannot make Constant refer to non-constant!");
+  Constant *To = cast<Constant>(ToV);
+
+  SmallVector<Constant*, 8> NewOps;
+  for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
+    Constant *Op = getOperand(i);
+    NewOps.push_back(Op == From ? To : Op);
+  }
+
+  Constant *Replacement = getWithOperands(NewOps);
+  assert(Replacement != this && "I didn't contain From!");
+
+  // Everyone using this now uses the replacement.
+  replaceAllUsesWith(Replacement);
+
+  // Delete the old constant!
+  destroyConstant();
+}
+
+Instruction *ConstantExpr::getAsInstruction() {
+  SmallVector<Value*,4> ValueOperands;
+  for (op_iterator I = op_begin(), E = op_end(); I != E; ++I)
+    ValueOperands.push_back(cast<Value>(I));
+
+  ArrayRef<Value*> Ops(ValueOperands);
+
+  switch (getOpcode()) {
+  case Instruction::Trunc:
+  case Instruction::ZExt:
+  case Instruction::SExt:
+  case Instruction::FPTrunc:
+  case Instruction::FPExt:
+  case Instruction::UIToFP:
+  case Instruction::SIToFP:
+  case Instruction::FPToUI:
+  case Instruction::FPToSI:
+  case Instruction::PtrToInt:
+  case Instruction::IntToPtr:
+  case Instruction::BitCast:
+    return CastInst::Create((Instruction::CastOps)getOpcode(),
+                            Ops[0], getType());
+  case Instruction::Select:
+    return SelectInst::Create(Ops[0], Ops[1], Ops[2]);
+  case Instruction::InsertElement:
+    return InsertElementInst::Create(Ops[0], Ops[1], Ops[2]);
+  case Instruction::ExtractElement:
+    return ExtractElementInst::Create(Ops[0], Ops[1]);
+  case Instruction::InsertValue:
+    return InsertValueInst::Create(Ops[0], Ops[1], getIndices());
+  case Instruction::ExtractValue:
+    return ExtractValueInst::Create(Ops[0], getIndices());
+  case Instruction::ShuffleVector:
+    return new ShuffleVectorInst(Ops[0], Ops[1], Ops[2]);
+
+  case Instruction::GetElementPtr:
+    if (cast<GEPOperator>(this)->isInBounds())
+      return GetElementPtrInst::CreateInBounds(Ops[0], Ops.slice(1));
+    else
+      return GetElementPtrInst::Create(Ops[0], Ops.slice(1));
+
+  case Instruction::ICmp:
+  case Instruction::FCmp:
+    return CmpInst::Create((Instruction::OtherOps)getOpcode(),
+                           getPredicate(), Ops[0], Ops[1]);
+
+  default:
+    assert(getNumOperands() == 2 && "Must be binary operator?");
+    BinaryOperator *BO =
+      BinaryOperator::Create((Instruction::BinaryOps)getOpcode(),
+                             Ops[0], Ops[1]);
+    if (isa<OverflowingBinaryOperator>(BO)) {
+      BO->setHasNoUnsignedWrap(SubclassOptionalData &
+                               OverflowingBinaryOperator::NoUnsignedWrap);
+      BO->setHasNoSignedWrap(SubclassOptionalData &
+                             OverflowingBinaryOperator::NoSignedWrap);
+    }
+    if (isa<PossiblyExactOperator>(BO))
+      BO->setIsExact(SubclassOptionalData & PossiblyExactOperator::IsExact);
+    return BO;
+  }
+}