Rename VMCore directory to IR.

Aside from moving the actual files, this patch only updates the build
system and the source file comments under lib/... that are relevant.

I'll be updating other docs and other files in smaller subsequnet
commits.

While I've tried to test this, but it is entirely possible that there
will still be some build system fallout.

Also, note that I've not changed the library name itself: libLLVMCore.a
is still the library name. I'd be interested in others' opinions about
whether we should rename this as well (I think we should, just not sure
what it might break)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171359 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2769 insertions, 0 deletions

diff --git a/lib/IR/Constants.cpp b/lib/IR/Constants.cpp
new file mode 100644
index 0000000000..a97b620768
--- /dev/null
+++ b/lib/IR/Constants.cpp
@@ -0,0 +1,2769 @@
+//===-- 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/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/DerivedTypes.h"
+#include "llvm/GlobalValue.h"
+#include "llvm/Instructions.h"
+#include "llvm/Module.h"
+#include "llvm/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();
+
+  // 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(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
+  std::vector<Constant*> argVec(1, C);
+  ExprMapKeyType Key(opc, argVec);
+
+  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()->isPointerTy() && "Invalid cast");
+  assert((Ty->isIntegerTy() || Ty->isPointerTy()) && "Invalid cast");
+
+  if (Ty->isIntegerTy())
+    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.
+
+  std::vector<Constant*> argVec(1, C1);
+  argVec.push_back(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
+
+  std::vector<Constant*> argVec(3, C);
+  argVec[1] = V1;
+  argVec[2] = 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
+  std::vector<Constant*> ArgVec;
+  ArgVec.push_back(LHS);
+  ArgVec.push_back(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
+  std::vector<Constant*> ArgVec;
+  ArgVec.push_back(LHS);
+  ArgVec.push_back(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
+  std::vector<Constant*> ArgVec(1, Val);
+  ArgVec.push_back(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
+  std::vector<Constant*> ArgVec(1, Val);
+  ArgVec.push_back(Elt);
+  ArgVec.push_back(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
+  std::vector<Constant*> ArgVec(1, V1);
+  ArgVec.push_back(V2);
+  ArgVec.push_back(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;
+  }
+}