intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 3509 insertions, 0 deletions

diff --git a/contrib/libs/llvm12/lib/IR/Constants.cpp b/contrib/libs/llvm12/lib/IR/Constants.cpp
new file mode 100644
index 0000000000..9f05917cf7
--- /dev/null
+++ b/contrib/libs/llvm12/lib/IR/Constants.cpp
@@ -0,0 +1,3509 @@
+//===-- Constants.cpp - Implement Constant nodes --------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the Constant* classes.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/IR/Constants.h"
+#include "ConstantFold.h"
+#include "LLVMContextImpl.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/GetElementPtrTypeIterator.h"
+#include "llvm/IR/GlobalValue.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Operator.h"
+#include "llvm/IR/PatternMatch.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+
+using namespace llvm;
+using namespace PatternMatch;
+
+//===----------------------------------------------------------------------===//
+//                              Constant Class
+//===----------------------------------------------------------------------===//
+
+bool Constant::isNegativeZeroValue() const {
+  // Floating point values have an explicit -0.0 value.
+  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
+    return CFP->isZero() && CFP->isNegative();
+
+  // Equivalent for a vector of -0.0's.
+  if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
+    if (CV->getElementType()->isFloatingPointTy() && CV->isSplat())
+      if (CV->getElementAsAPFloat(0).isNegZero())
+        return true;
+
+  if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
+    if (ConstantFP *SplatCFP = dyn_cast_or_null<ConstantFP>(CV->getSplatValue()))
+      if (SplatCFP && SplatCFP->isZero() && SplatCFP->isNegative())
+        return true;
+
+  // We've already handled true FP case; any other FP vectors can't represent -0.0.
+  if (getType()->isFPOrFPVectorTy())
+    return false;
+
+  // Otherwise, just use +0.0.
+  return isNullValue();
+}
+
+// Return true iff this constant is positive zero (floating point), negative
+// zero (floating point), or a null value.
+bool Constant::isZeroValue() const {
+  // Floating point values have an explicit -0.0 value.
+  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
+    return CFP->isZero();
+
+  // Equivalent for a vector of -0.0's.
+  if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
+    if (CV->getElementType()->isFloatingPointTy() && CV->isSplat())
+      if (CV->getElementAsAPFloat(0).isZero())
+        return true;
+
+  if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
+    if (ConstantFP *SplatCFP = dyn_cast_or_null<ConstantFP>(CV->getSplatValue()))
+      if (SplatCFP && SplatCFP->isZero())
+        return true;
+
+  // 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, cpnull is null for pointers, none for
+  // tokens.
+  return isa<ConstantAggregateZero>(this) || isa<ConstantPointerNull>(this) ||
+         isa<ConstantTokenNone>(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 (CV->isSplat()) {
+      if (CV->getElementType()->isFloatingPointTy())
+        return CV->getElementAsAPFloat(0).bitcastToAPInt().isAllOnesValue();
+      return CV->getElementAsAPInt(0).isAllOnesValue();
+    }
+  }
+
+  return false;
+}
+
+bool Constant::isOneValue() const {
+  // Check for 1 integers
+  if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
+    return CI->isOne();
+
+  // Check for FP which are bitcasted from 1 integers
+  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
+    return CFP->getValueAPF().bitcastToAPInt().isOneValue();
+
+  // 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->isOneValue();
+
+  // Check for constant vectors which are splats of 1 values.
+  if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this)) {
+    if (CV->isSplat()) {
+      if (CV->getElementType()->isFloatingPointTy())
+        return CV->getElementAsAPFloat(0).bitcastToAPInt().isOneValue();
+      return CV->getElementAsAPInt(0).isOneValue();
+    }
+  }
+
+  return false;
+}
+
+bool Constant::isNotOneValue() const {
+  // Check for 1 integers
+  if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
+    return !CI->isOneValue();
+
+  // Check for FP which are bitcasted from 1 integers
+  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
+    return !CFP->getValueAPF().bitcastToAPInt().isOneValue();
+
+  // Check that vectors don't contain 1
+  if (auto *VTy = dyn_cast<VectorType>(this->getType())) {
+    unsigned NumElts = cast<FixedVectorType>(VTy)->getNumElements();
+    for (unsigned i = 0; i != NumElts; ++i) {
+      Constant *Elt = this->getAggregateElement(i);
+      if (!Elt || !Elt->isNotOneValue())
+        return false;
+    }
+    return true;
+  }
+
+  // It *may* contain 1, we can't tell.
+  return false;
+}
+
+bool Constant::isMinSignedValue() const {
+  // Check for INT_MIN integers
+  if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
+    return CI->isMinValue(/*isSigned=*/true);
+
+  // Check for FP which are bitcasted from INT_MIN integers
+  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
+    return CFP->getValueAPF().bitcastToAPInt().isMinSignedValue();
+
+  // Check for constant vectors which are splats of INT_MIN values.
+  if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
+    if (Constant *Splat = CV->getSplatValue())
+      return Splat->isMinSignedValue();
+
+  // Check for constant vectors which are splats of INT_MIN values.
+  if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this)) {
+    if (CV->isSplat()) {
+      if (CV->getElementType()->isFloatingPointTy())
+        return CV->getElementAsAPFloat(0).bitcastToAPInt().isMinSignedValue();
+      return CV->getElementAsAPInt(0).isMinSignedValue();
+    }
+  }
+
+  return false;
+}
+
+bool Constant::isNotMinSignedValue() const {
+  // Check for INT_MIN integers
+  if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
+    return !CI->isMinValue(/*isSigned=*/true);
+
+  // Check for FP which are bitcasted from INT_MIN integers
+  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
+    return !CFP->getValueAPF().bitcastToAPInt().isMinSignedValue();
+
+  // Check that vectors don't contain INT_MIN
+  if (auto *VTy = dyn_cast<VectorType>(this->getType())) {
+    unsigned NumElts = cast<FixedVectorType>(VTy)->getNumElements();
+    for (unsigned i = 0; i != NumElts; ++i) {
+      Constant *Elt = this->getAggregateElement(i);
+      if (!Elt || !Elt->isNotMinSignedValue())
+        return false;
+    }
+    return true;
+  }
+
+  // It *may* contain INT_MIN, we can't tell.
+  return false;
+}
+
+bool Constant::isFiniteNonZeroFP() const {
+  if (auto *CFP = dyn_cast<ConstantFP>(this))
+    return CFP->getValueAPF().isFiniteNonZero();
+  auto *VTy = dyn_cast<FixedVectorType>(getType());
+  if (!VTy)
+    return false;
+  for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+    auto *CFP = dyn_cast_or_null<ConstantFP>(this->getAggregateElement(i));
+    if (!CFP || !CFP->getValueAPF().isFiniteNonZero())
+      return false;
+  }
+  return true;
+}
+
+bool Constant::isNormalFP() const {
+  if (auto *CFP = dyn_cast<ConstantFP>(this))
+    return CFP->getValueAPF().isNormal();
+  auto *VTy = dyn_cast<FixedVectorType>(getType());
+  if (!VTy)
+    return false;
+  for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+    auto *CFP = dyn_cast_or_null<ConstantFP>(this->getAggregateElement(i));
+    if (!CFP || !CFP->getValueAPF().isNormal())
+      return false;
+  }
+  return true;
+}
+
+bool Constant::hasExactInverseFP() const {
+  if (auto *CFP = dyn_cast<ConstantFP>(this))
+    return CFP->getValueAPF().getExactInverse(nullptr);
+  auto *VTy = dyn_cast<FixedVectorType>(getType());
+  if (!VTy)
+    return false;
+  for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+    auto *CFP = dyn_cast_or_null<ConstantFP>(this->getAggregateElement(i));
+    if (!CFP || !CFP->getValueAPF().getExactInverse(nullptr))
+      return false;
+  }
+  return true;
+}
+
+bool Constant::isNaN() const {
+  if (auto *CFP = dyn_cast<ConstantFP>(this))
+    return CFP->isNaN();
+  auto *VTy = dyn_cast<FixedVectorType>(getType());
+  if (!VTy)
+    return false;
+  for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+    auto *CFP = dyn_cast_or_null<ConstantFP>(this->getAggregateElement(i));
+    if (!CFP || !CFP->isNaN())
+      return false;
+  }
+  return true;
+}
+
+bool Constant::isElementWiseEqual(Value *Y) const {
+  // Are they fully identical?
+  if (this == Y)
+    return true;
+
+  // The input value must be a vector constant with the same type.
+  auto *VTy = dyn_cast<VectorType>(getType());
+  if (!isa<Constant>(Y) || !VTy || VTy != Y->getType())
+    return false;
+
+  // TODO: Compare pointer constants?
+  if (!(VTy->getElementType()->isIntegerTy() ||
+        VTy->getElementType()->isFloatingPointTy()))
+    return false;
+
+  // They may still be identical element-wise (if they have `undef`s).
+  // Bitcast to integer to allow exact bitwise comparison for all types.
+  Type *IntTy = VectorType::getInteger(VTy);
+  Constant *C0 = ConstantExpr::getBitCast(const_cast<Constant *>(this), IntTy);
+  Constant *C1 = ConstantExpr::getBitCast(cast<Constant>(Y), IntTy);
+  Constant *CmpEq = ConstantExpr::getICmp(ICmpInst::ICMP_EQ, C0, C1);
+  return isa<UndefValue>(CmpEq) || match(CmpEq, m_One());
+}
+
+static bool
+containsUndefinedElement(const Constant *C,
+                         function_ref<bool(const Constant *)> HasFn) {
+  if (auto *VTy = dyn_cast<VectorType>(C->getType())) {
+    if (HasFn(C))
+      return true;
+    if (isa<ConstantAggregateZero>(C))
+      return false;
+    if (isa<ScalableVectorType>(C->getType()))
+      return false;
+
+    for (unsigned i = 0, e = cast<FixedVectorType>(VTy)->getNumElements();
+         i != e; ++i)
+      if (HasFn(C->getAggregateElement(i)))
+        return true;
+  }
+
+  return false;
+}
+
+bool Constant::containsUndefOrPoisonElement() const {
+  return containsUndefinedElement(
+      this, [&](const auto *C) { return isa<UndefValue>(C); });
+}
+
+bool Constant::containsPoisonElement() const {
+  return containsUndefinedElement(
+      this, [&](const auto *C) { return isa<PoisonValue>(C); });
+}
+
+bool Constant::containsConstantExpression() const {
+  if (auto *VTy = dyn_cast<FixedVectorType>(getType())) {
+    for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i)
+      if (isa<ConstantExpr>(getAggregateElement(i)))
+        return true;
+  }
+  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::BFloatTyID:
+    return ConstantFP::get(Ty->getContext(),
+                           APFloat::getZero(APFloat::BFloat()));
+  case Type::FloatTyID:
+    return ConstantFP::get(Ty->getContext(),
+                           APFloat::getZero(APFloat::IEEEsingle()));
+  case Type::DoubleTyID:
+    return ConstantFP::get(Ty->getContext(),
+                           APFloat::getZero(APFloat::IEEEdouble()));
+  case Type::X86_FP80TyID:
+    return ConstantFP::get(Ty->getContext(),
+                           APFloat::getZero(APFloat::x87DoubleExtended()));
+  case Type::FP128TyID:
+    return ConstantFP::get(Ty->getContext(),
+                           APFloat::getZero(APFloat::IEEEquad()));
+  case Type::PPC_FP128TyID:
+    return ConstantFP::get(Ty->getContext(),
+                           APFloat(APFloat::PPCDoubleDouble(),
+                                   APInt::getNullValue(128)));
+  case Type::PointerTyID:
+    return ConstantPointerNull::get(cast<PointerType>(Ty));
+  case Type::StructTyID:
+  case Type::ArrayTyID:
+  case Type::FixedVectorTyID:
+  case Type::ScalableVectorTyID:
+    return ConstantAggregateZero::get(Ty);
+  case Type::TokenTyID:
+    return ConstantTokenNone::get(Ty->getContext());
+  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->getElementCount(), 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->getFltSemantics(),
+                                          Ty->getPrimitiveSizeInBits());
+    return ConstantFP::get(Ty->getContext(), FL);
+  }
+
+  VectorType *VTy = cast<VectorType>(Ty);
+  return ConstantVector::getSplat(VTy->getElementCount(),
+                                  getAllOnesValue(VTy->getElementType()));
+}
+
+Constant *Constant::getAggregateElement(unsigned Elt) const {
+  if (const auto *CC = dyn_cast<ConstantAggregate>(this))
+    return Elt < CC->getNumOperands() ? CC->getOperand(Elt) : nullptr;
+
+  // FIXME: getNumElements() will fail for non-fixed vector types.
+  if (isa<ScalableVectorType>(getType()))
+    return nullptr;
+
+  if (const auto *CAZ = dyn_cast<ConstantAggregateZero>(this))
+    return Elt < CAZ->getNumElements() ? CAZ->getElementValue(Elt) : nullptr;
+
+  if (const auto *PV = dyn_cast<PoisonValue>(this))
+    return Elt < PV->getNumElements() ? PV->getElementValue(Elt) : nullptr;
+
+  if (const auto *UV = dyn_cast<UndefValue>(this))
+    return Elt < UV->getNumElements() ? UV->getElementValue(Elt) : nullptr;
+
+  if (const auto *CDS = dyn_cast<ConstantDataSequential>(this))
+    return Elt < CDS->getNumElements() ? CDS->getElementAsConstant(Elt)
+                                       : nullptr;
+  return nullptr;
+}
+
+Constant *Constant::getAggregateElement(Constant *Elt) const {
+  assert(isa<IntegerType>(Elt->getType()) && "Index must be an integer");
+  if (ConstantInt *CI = dyn_cast<ConstantInt>(Elt)) {
+    // Check if the constant fits into an uint64_t.
+    if (CI->getValue().getActiveBits() > 64)
+      return nullptr;
+    return getAggregateElement(CI->getZExtValue());
+  }
+  return nullptr;
+}
+
+void Constant::destroyConstant() {
+  /// First call destroyConstantImpl on the subclass.  This gives the subclass
+  /// a chance to remove the constant from any maps/pools it's contained in.
+  switch (getValueID()) {
+  default:
+    llvm_unreachable("Not a constant!");
+#define HANDLE_CONSTANT(Name)                                                  \
+  case Value::Name##Val:                                                       \
+    cast<Name>(this)->destroyConstantImpl();                                   \
+    break;
+#include "llvm/IR/Value.def"
+  }
+
+  // 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 = user_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() || user_back() != V) && "Constant not removed!");
+  }
+
+  // Value has no outstanding references it is safe to delete it now...
+  deleteConstant(this);
+}
+
+void llvm::deleteConstant(Constant *C) {
+  switch (C->getValueID()) {
+  case Constant::ConstantIntVal:
+    delete static_cast<ConstantInt *>(C);
+    break;
+  case Constant::ConstantFPVal:
+    delete static_cast<ConstantFP *>(C);
+    break;
+  case Constant::ConstantAggregateZeroVal:
+    delete static_cast<ConstantAggregateZero *>(C);
+    break;
+  case Constant::ConstantArrayVal:
+    delete static_cast<ConstantArray *>(C);
+    break;
+  case Constant::ConstantStructVal:
+    delete static_cast<ConstantStruct *>(C);
+    break;
+  case Constant::ConstantVectorVal:
+    delete static_cast<ConstantVector *>(C);
+    break;
+  case Constant::ConstantPointerNullVal:
+    delete static_cast<ConstantPointerNull *>(C);
+    break;
+  case Constant::ConstantDataArrayVal:
+    delete static_cast<ConstantDataArray *>(C);
+    break;
+  case Constant::ConstantDataVectorVal:
+    delete static_cast<ConstantDataVector *>(C);
+    break;
+  case Constant::ConstantTokenNoneVal:
+    delete static_cast<ConstantTokenNone *>(C);
+    break;
+  case Constant::BlockAddressVal:
+    delete static_cast<BlockAddress *>(C);
+    break;
+  case Constant::DSOLocalEquivalentVal:
+    delete static_cast<DSOLocalEquivalent *>(C);
+    break;
+  case Constant::UndefValueVal:
+    delete static_cast<UndefValue *>(C);
+    break;
+  case Constant::PoisonValueVal:
+    delete static_cast<PoisonValue *>(C);
+    break;
+  case Constant::ConstantExprVal:
+    if (isa<UnaryConstantExpr>(C))
+      delete static_cast<UnaryConstantExpr *>(C);
+    else if (isa<BinaryConstantExpr>(C))
+      delete static_cast<BinaryConstantExpr *>(C);
+    else if (isa<SelectConstantExpr>(C))
+      delete static_cast<SelectConstantExpr *>(C);
+    else if (isa<ExtractElementConstantExpr>(C))
+      delete static_cast<ExtractElementConstantExpr *>(C);
+    else if (isa<InsertElementConstantExpr>(C))
+      delete static_cast<InsertElementConstantExpr *>(C);
+    else if (isa<ShuffleVectorConstantExpr>(C))
+      delete static_cast<ShuffleVectorConstantExpr *>(C);
+    else if (isa<ExtractValueConstantExpr>(C))
+      delete static_cast<ExtractValueConstantExpr *>(C);
+    else if (isa<InsertValueConstantExpr>(C))
+      delete static_cast<InsertValueConstantExpr *>(C);
+    else if (isa<GetElementPtrConstantExpr>(C))
+      delete static_cast<GetElementPtrConstantExpr *>(C);
+    else if (isa<CompareConstantExpr>(C))
+      delete static_cast<CompareConstantExpr *>(C);
+    else
+      llvm_unreachable("Unexpected constant expr");
+    break;
+  default:
+    llvm_unreachable("Unexpected constant");
+  }
+}
+
+static bool canTrapImpl(const Constant *C,
+                        SmallPtrSetImpl<const ConstantExpr *> &NonTrappingOps) {
+  assert(C->getType()->isFirstClassType() && "Cannot evaluate aggregate vals!");
+  // The only thing that could possibly trap are constant exprs.
+  const ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
+  if (!CE)
+    return false;
+
+  // ConstantExpr traps if any operands can trap.
+  for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i) {
+    if (ConstantExpr *Op = dyn_cast<ConstantExpr>(CE->getOperand(i))) {
+      if (NonTrappingOps.insert(Op).second && canTrapImpl(Op, NonTrappingOps))
+        return true;
+    }
+  }
+
+  // Otherwise, only specific operations can trap.
+  switch (CE->getOpcode()) {
+  default:
+    return false;
+  case Instruction::UDiv:
+  case Instruction::SDiv:
+  case Instruction::URem:
+  case Instruction::SRem:
+    // 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;
+  }
+}
+
+bool Constant::canTrap() const {
+  SmallPtrSet<const ConstantExpr *, 4> NonTrappingOps;
+  return canTrapImpl(this, NonTrappingOps);
+}
+
+/// Check if C contains a GlobalValue for which Predicate is true.
+static bool
+ConstHasGlobalValuePredicate(const Constant *C,
+                             bool (*Predicate)(const GlobalValue *)) {
+  SmallPtrSet<const Constant *, 8> Visited;
+  SmallVector<const Constant *, 8> WorkList;
+  WorkList.push_back(C);
+  Visited.insert(C);
+
+  while (!WorkList.empty()) {
+    const Constant *WorkItem = WorkList.pop_back_val();
+    if (const auto *GV = dyn_cast<GlobalValue>(WorkItem))
+      if (Predicate(GV))
+        return true;
+    for (const Value *Op : WorkItem->operands()) {
+      const Constant *ConstOp = dyn_cast<Constant>(Op);
+      if (!ConstOp)
+        continue;
+      if (Visited.insert(ConstOp).second)
+        WorkList.push_back(ConstOp);
+    }
+  }
+  return false;
+}
+
+bool Constant::isThreadDependent() const {
+  auto DLLImportPredicate = [](const GlobalValue *GV) {
+    return GV->isThreadLocal();
+  };
+  return ConstHasGlobalValuePredicate(this, DLLImportPredicate);
+}
+
+bool Constant::isDLLImportDependent() const {
+  auto DLLImportPredicate = [](const GlobalValue *GV) {
+    return GV->hasDLLImportStorageClass();
+  };
+  return ConstHasGlobalValuePredicate(this, DLLImportPredicate);
+}
+
+bool Constant::isConstantUsed() const {
+  for (const User *U : users()) {
+    const Constant *UC = dyn_cast<Constant>(U);
+    if (!UC || isa<GlobalValue>(UC))
+      return true;
+
+    if (UC->isConstantUsed())
+      return true;
+  }
+  return false;
+}
+
+bool Constant::needsRelocation() const {
+  if (isa<GlobalValue>(this))
+    return true; // Global reference.
+
+  if (const BlockAddress *BA = dyn_cast<BlockAddress>(this))
+    return BA->getFunction()->needsRelocation();
+
+  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) {
+        Constant *LHSOp0 = LHS->getOperand(0);
+        Constant *RHSOp0 = RHS->getOperand(0);
+
+        // 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 (isa<BlockAddress>(LHSOp0) && isa<BlockAddress>(RHSOp0) &&
+            cast<BlockAddress>(LHSOp0)->getFunction() ==
+                cast<BlockAddress>(RHSOp0)->getFunction())
+          return false;
+
+        // Relative pointers do not need to be dynamically relocated.
+        if (auto *RHSGV =
+                dyn_cast<GlobalValue>(RHSOp0->stripInBoundsConstantOffsets())) {
+          auto *LHS = LHSOp0->stripInBoundsConstantOffsets();
+          if (auto *LHSGV = dyn_cast<GlobalValue>(LHS)) {
+            if (LHSGV->isDSOLocal() && RHSGV->isDSOLocal())
+              return false;
+          } else if (isa<DSOLocalEquivalent>(LHS)) {
+            if (RHSGV->isDSOLocal())
+              return false;
+          }
+        }
+      }
+    }
+  }
+
+  bool Result = false;
+  for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
+    Result |= cast<Constant>(getOperand(i))->needsRelocation();
+
+  return Result;
+}
+
+/// 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->user_back());
+    if (!User) return false; // Non-constant usage;
+    if (!removeDeadUsersOfConstant(User))
+      return false; // Constant wasn't dead
+  }
+
+  const_cast<Constant*>(C)->destroyConstant();
+  return true;
+}
+
+
+void Constant::removeDeadConstantUsers() const {
+  Value::const_user_iterator I = user_begin(), E = user_end();
+  Value::const_user_iterator LastNonDeadUser = E;
+  while (I != E) {
+    const Constant *User = dyn_cast<Constant>(*I);
+    if (!User) {
+      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 = user_begin();
+    else
+      I = std::next(LastNonDeadUser);
+  }
+}
+
+Constant *Constant::replaceUndefsWith(Constant *C, Constant *Replacement) {
+  assert(C && Replacement && "Expected non-nullptr constant arguments");
+  Type *Ty = C->getType();
+  if (match(C, m_Undef())) {
+    assert(Ty == Replacement->getType() && "Expected matching types");
+    return Replacement;
+  }
+
+  // Don't know how to deal with this constant.
+  auto *VTy = dyn_cast<FixedVectorType>(Ty);
+  if (!VTy)
+    return C;
+
+  unsigned NumElts = VTy->getNumElements();
+  SmallVector<Constant *, 32> NewC(NumElts);
+  for (unsigned i = 0; i != NumElts; ++i) {
+    Constant *EltC = C->getAggregateElement(i);
+    assert((!EltC || EltC->getType() == Replacement->getType()) &&
+           "Expected matching types");
+    NewC[i] = EltC && match(EltC, m_Undef()) ? Replacement : EltC;
+  }
+  return ConstantVector::get(NewC);
+}
+
+Constant *Constant::mergeUndefsWith(Constant *C, Constant *Other) {
+  assert(C && Other && "Expected non-nullptr constant arguments");
+  if (match(C, m_Undef()))
+    return C;
+
+  Type *Ty = C->getType();
+  if (match(Other, m_Undef()))
+    return UndefValue::get(Ty);
+
+  auto *VTy = dyn_cast<FixedVectorType>(Ty);
+  if (!VTy)
+    return C;
+
+  Type *EltTy = VTy->getElementType();
+  unsigned NumElts = VTy->getNumElements();
+  assert(isa<FixedVectorType>(Other->getType()) &&
+         cast<FixedVectorType>(Other->getType())->getNumElements() == NumElts &&
+         "Type mismatch");
+
+  bool FoundExtraUndef = false;
+  SmallVector<Constant *, 32> NewC(NumElts);
+  for (unsigned I = 0; I != NumElts; ++I) {
+    NewC[I] = C->getAggregateElement(I);
+    Constant *OtherEltC = Other->getAggregateElement(I);
+    assert(NewC[I] && OtherEltC && "Unknown vector element");
+    if (!match(NewC[I], m_Undef()) && match(OtherEltC, m_Undef())) {
+      NewC[I] = UndefValue::get(EltTy);
+      FoundExtraUndef = true;
+    }
+  }
+  if (FoundExtraUndef)
+    return ConstantVector::get(NewC);
+  return C;
+}
+
+bool Constant::isManifestConstant() const {
+  if (isa<ConstantData>(this))
+    return true;
+  if (isa<ConstantAggregate>(this) || isa<ConstantExpr>(this)) {
+    for (const Value *Op : operand_values())
+      if (!cast<Constant>(Op)->isManifestConstant())
+        return false;
+    return true;
+  }
+  return false;
+}
+
+//===----------------------------------------------------------------------===//
+//                                ConstantInt
+//===----------------------------------------------------------------------===//
+
+ConstantInt::ConstantInt(IntegerType *Ty, const APInt &V)
+    : ConstantData(Ty, ConstantIntVal), 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;
+}
+
+ConstantInt *ConstantInt::getBool(LLVMContext &Context, bool V) {
+  return V ? getTrue(Context) : getFalse(Context);
+}
+
+Constant *ConstantInt::getTrue(Type *Ty) {
+  assert(Ty->isIntOrIntVectorTy(1) && "Type not i1 or vector of i1.");
+  ConstantInt *TrueC = ConstantInt::getTrue(Ty->getContext());
+  if (auto *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getElementCount(), TrueC);
+  return TrueC;
+}
+
+Constant *ConstantInt::getFalse(Type *Ty) {
+  assert(Ty->isIntOrIntVectorTy(1) && "Type not i1 or vector of i1.");
+  ConstantInt *FalseC = ConstantInt::getFalse(Ty->getContext());
+  if (auto *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getElementCount(), FalseC);
+  return FalseC;
+}
+
+Constant *ConstantInt::getBool(Type *Ty, bool V) {
+  return V ? getTrue(Ty) : getFalse(Ty);
+}
+
+// Get a ConstantInt from an APInt.
+ConstantInt *ConstantInt::get(LLVMContext &Context, const APInt &V) {
+  // get an existing value or the insertion position
+  LLVMContextImpl *pImpl = Context.pImpl;
+  std::unique_ptr<ConstantInt> &Slot = pImpl->IntConstants[V];
+  if (!Slot) {
+    // Get the corresponding integer type for the bit width of the value.
+    IntegerType *ITy = IntegerType::get(Context, V.getBitWidth());
+    Slot.reset(new ConstantInt(ITy, V));
+  }
+  assert(Slot->getType() == IntegerType::get(Context, V.getBitWidth()));
+  return Slot.get();
+}
+
+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->getElementCount(), 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->getElementCount(), C);
+
+  return C;
+}
+
+ConstantInt *ConstantInt::get(IntegerType* Ty, StringRef Str, uint8_t radix) {
+  return get(Ty->getContext(), APInt(Ty->getBitWidth(), Str, radix));
+}
+
+/// Remove the constant from the constant table.
+void ConstantInt::destroyConstantImpl() {
+  llvm_unreachable("You can't ConstantInt->destroyConstantImpl()!");
+}
+
+//===----------------------------------------------------------------------===//
+//                                ConstantFP
+//===----------------------------------------------------------------------===//
+
+Constant *ConstantFP::get(Type *Ty, double V) {
+  LLVMContext &Context = Ty->getContext();
+
+  APFloat FV(V);
+  bool ignored;
+  FV.convert(Ty->getScalarType()->getFltSemantics(),
+             APFloat::rmNearestTiesToEven, &ignored);
+  Constant *C = get(Context, FV);
+
+  // For vectors, broadcast the value.
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getElementCount(), C);
+
+  return C;
+}
+
+Constant *ConstantFP::get(Type *Ty, const APFloat &V) {
+  ConstantFP *C = get(Ty->getContext(), V);
+  assert(C->getType() == Ty->getScalarType() &&
+         "ConstantFP type doesn't match the type implied by its value!");
+
+  // For vectors, broadcast the value.
+  if (auto *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getElementCount(), C);
+
+  return C;
+}
+
+Constant *ConstantFP::get(Type *Ty, StringRef Str) {
+  LLVMContext &Context = Ty->getContext();
+
+  APFloat FV(Ty->getScalarType()->getFltSemantics(), Str);
+  Constant *C = get(Context, FV);
+
+  // For vectors, broadcast the value.
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getElementCount(), C);
+
+  return C;
+}
+
+Constant *ConstantFP::getNaN(Type *Ty, bool Negative, uint64_t Payload) {
+  const fltSemantics &Semantics = Ty->getScalarType()->getFltSemantics();
+  APFloat NaN = APFloat::getNaN(Semantics, Negative, Payload);
+  Constant *C = get(Ty->getContext(), NaN);
+
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getElementCount(), C);
+
+  return C;
+}
+
+Constant *ConstantFP::getQNaN(Type *Ty, bool Negative, APInt *Payload) {
+  const fltSemantics &Semantics = Ty->getScalarType()->getFltSemantics();
+  APFloat NaN = APFloat::getQNaN(Semantics, Negative, Payload);
+  Constant *C = get(Ty->getContext(), NaN);
+
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getElementCount(), C);
+
+  return C;
+}
+
+Constant *ConstantFP::getSNaN(Type *Ty, bool Negative, APInt *Payload) {
+  const fltSemantics &Semantics = Ty->getScalarType()->getFltSemantics();
+  APFloat NaN = APFloat::getSNaN(Semantics, Negative, Payload);
+  Constant *C = get(Ty->getContext(), NaN);
+
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getElementCount(), C);
+
+  return C;
+}
+
+Constant *ConstantFP::getNegativeZero(Type *Ty) {
+  const fltSemantics &Semantics = Ty->getScalarType()->getFltSemantics();
+  APFloat NegZero = APFloat::getZero(Semantics, /*Negative=*/true);
+  Constant *C = get(Ty->getContext(), NegZero);
+
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getElementCount(), C);
+
+  return C;
+}
+
+
+Constant *ConstantFP::getZeroValueForNegation(Type *Ty) {
+  if (Ty->isFPOrFPVectorTy())
+    return getNegativeZero(Ty);
+
+  return Constant::getNullValue(Ty);
+}
+
+
+// ConstantFP accessors.
+ConstantFP* ConstantFP::get(LLVMContext &Context, const APFloat& V) {
+  LLVMContextImpl* pImpl = Context.pImpl;
+
+  std::unique_ptr<ConstantFP> &Slot = pImpl->FPConstants[V];
+
+  if (!Slot) {
+    Type *Ty = Type::getFloatingPointTy(Context, V.getSemantics());
+    Slot.reset(new ConstantFP(Ty, V));
+  }
+
+  return Slot.get();
+}
+
+Constant *ConstantFP::getInfinity(Type *Ty, bool Negative) {
+  const fltSemantics &Semantics = Ty->getScalarType()->getFltSemantics();
+  Constant *C = get(Ty->getContext(), APFloat::getInf(Semantics, Negative));
+
+  if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+    return ConstantVector::getSplat(VTy->getElementCount(), C);
+
+  return C;
+}
+
+ConstantFP::ConstantFP(Type *Ty, const APFloat &V)
+    : ConstantData(Ty, ConstantFPVal), Val(V) {
+  assert(&V.getSemantics() == &Ty->getFltSemantics() &&
+         "FP type Mismatch");
+}
+
+bool ConstantFP::isExactlyValue(const APFloat &V) const {
+  return Val.bitwiseIsEqual(V);
+}
+
+/// Remove the constant from the constant table.
+void ConstantFP::destroyConstantImpl() {
+  llvm_unreachable("You can't ConstantFP->destroyConstantImpl()!");
+}
+
+//===----------------------------------------------------------------------===//
+//                   ConstantAggregateZero Implementation
+//===----------------------------------------------------------------------===//
+
+Constant *ConstantAggregateZero::getSequentialElement() const {
+  if (auto *AT = dyn_cast<ArrayType>(getType()))
+    return Constant::getNullValue(AT->getElementType());
+  return Constant::getNullValue(cast<VectorType>(getType())->getElementType());
+}
+
+Constant *ConstantAggregateZero::getStructElement(unsigned Elt) const {
+  return Constant::getNullValue(getType()->getStructElementType(Elt));
+}
+
+Constant *ConstantAggregateZero::getElementValue(Constant *C) const {
+  if (isa<ArrayType>(getType()) || isa<VectorType>(getType()))
+    return getSequentialElement();
+  return getStructElement(cast<ConstantInt>(C)->getZExtValue());
+}
+
+Constant *ConstantAggregateZero::getElementValue(unsigned Idx) const {
+  if (isa<ArrayType>(getType()) || isa<VectorType>(getType()))
+    return getSequentialElement();
+  return getStructElement(Idx);
+}
+
+unsigned ConstantAggregateZero::getNumElements() const {
+  Type *Ty = getType();
+  if (auto *AT = dyn_cast<ArrayType>(Ty))
+    return AT->getNumElements();
+  if (auto *VT = dyn_cast<VectorType>(Ty))
+    return cast<FixedVectorType>(VT)->getNumElements();
+  return Ty->getStructNumElements();
+}
+
+//===----------------------------------------------------------------------===//
+//                         UndefValue Implementation
+//===----------------------------------------------------------------------===//
+
+UndefValue *UndefValue::getSequentialElement() const {
+  if (ArrayType *ATy = dyn_cast<ArrayType>(getType()))
+    return UndefValue::get(ATy->getElementType());
+  return UndefValue::get(cast<VectorType>(getType())->getElementType());
+}
+
+UndefValue *UndefValue::getStructElement(unsigned Elt) const {
+  return UndefValue::get(getType()->getStructElementType(Elt));
+}
+
+UndefValue *UndefValue::getElementValue(Constant *C) const {
+  if (isa<ArrayType>(getType()) || isa<VectorType>(getType()))
+    return getSequentialElement();
+  return getStructElement(cast<ConstantInt>(C)->getZExtValue());
+}
+
+UndefValue *UndefValue::getElementValue(unsigned Idx) const {
+  if (isa<ArrayType>(getType()) || isa<VectorType>(getType()))
+    return getSequentialElement();
+  return getStructElement(Idx);
+}
+
+unsigned UndefValue::getNumElements() const {
+  Type *Ty = getType();
+  if (auto *AT = dyn_cast<ArrayType>(Ty))
+    return AT->getNumElements();
+  if (auto *VT = dyn_cast<VectorType>(Ty))
+    return cast<FixedVectorType>(VT)->getNumElements();
+  return Ty->getStructNumElements();
+}
+
+//===----------------------------------------------------------------------===//
+//                         PoisonValue Implementation
+//===----------------------------------------------------------------------===//
+
+PoisonValue *PoisonValue::getSequentialElement() const {
+  if (ArrayType *ATy = dyn_cast<ArrayType>(getType()))
+    return PoisonValue::get(ATy->getElementType());
+  return PoisonValue::get(cast<VectorType>(getType())->getElementType());
+}
+
+PoisonValue *PoisonValue::getStructElement(unsigned Elt) const {
+  return PoisonValue::get(getType()->getStructElementType(Elt));
+}
+
+PoisonValue *PoisonValue::getElementValue(Constant *C) const {
+  if (isa<ArrayType>(getType()) || isa<VectorType>(getType()))
+    return getSequentialElement();
+  return getStructElement(cast<ConstantInt>(C)->getZExtValue());
+}
+
+PoisonValue *PoisonValue::getElementValue(unsigned Idx) const {
+  if (isa<ArrayType>(getType()) || isa<VectorType>(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;
+}
+
+template <typename SequentialTy, typename ElementTy>
+static Constant *getIntSequenceIfElementsMatch(ArrayRef<Constant *> V) {
+  assert(!V.empty() && "Cannot get empty int sequence.");
+
+  SmallVector<ElementTy, 16> Elts;
+  for (Constant *C : V)
+    if (auto *CI = dyn_cast<ConstantInt>(C))
+      Elts.push_back(CI->getZExtValue());
+    else
+      return nullptr;
+  return SequentialTy::get(V[0]->getContext(), Elts);
+}
+
+template <typename SequentialTy, typename ElementTy>
+static Constant *getFPSequenceIfElementsMatch(ArrayRef<Constant *> V) {
+  assert(!V.empty() && "Cannot get empty FP sequence.");
+
+  SmallVector<ElementTy, 16> Elts;
+  for (Constant *C : V)
+    if (auto *CFP = dyn_cast<ConstantFP>(C))
+      Elts.push_back(CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
+    else
+      return nullptr;
+  return SequentialTy::getFP(V[0]->getType(), Elts);
+}
+
+template <typename SequenceTy>
+static Constant *getSequenceIfElementsMatch(Constant *C,
+                                            ArrayRef<Constant *> V) {
+  // We speculatively build the elements here even if it turns out that there is
+  // a constantexpr or something else weird, since it is so uncommon for that to
+  // happen.
+  if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
+    if (CI->getType()->isIntegerTy(8))
+      return getIntSequenceIfElementsMatch<SequenceTy, uint8_t>(V);
+    else if (CI->getType()->isIntegerTy(16))
+      return getIntSequenceIfElementsMatch<SequenceTy, uint16_t>(V);
+    else if (CI->getType()->isIntegerTy(32))
+      return getIntSequenceIfElementsMatch<SequenceTy, uint32_t>(V);
+    else if (CI->getType()->isIntegerTy(64))
+      return getIntSequenceIfElementsMatch<SequenceTy, uint64_t>(V);
+  } else if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
+    if (CFP->getType()->isHalfTy() || CFP->getType()->isBFloatTy())
+      return getFPSequenceIfElementsMatch<SequenceTy, uint16_t>(V);
+    else if (CFP->getType()->isFloatTy())
+      return getFPSequenceIfElementsMatch<SequenceTy, uint32_t>(V);
+    else if (CFP->getType()->isDoubleTy())
+      return getFPSequenceIfElementsMatch<SequenceTy, uint64_t>(V);
+  }
+
+  return nullptr;
+}
+
+ConstantAggregate::ConstantAggregate(Type *T, ValueTy VT,
+                                     ArrayRef<Constant *> V)
+    : Constant(T, VT, OperandTraits<ConstantAggregate>::op_end(this) - V.size(),
+               V.size()) {
+  llvm::copy(V, op_begin());
+
+  // Check that types match, unless this is an opaque struct.
+  if (auto *ST = dyn_cast<StructType>(T)) {
+    if (ST->isOpaque())
+      return;
+    for (unsigned I = 0, E = V.size(); I != E; ++I)
+      assert(V[I]->getType() == ST->getTypeAtIndex(I) &&
+             "Initializer for struct element doesn't match!");
+  }
+}
+
+ConstantArray::ConstantArray(ArrayType *T, ArrayRef<Constant *> V)
+    : ConstantAggregate(T, ConstantArrayVal, V) {
+  assert(V.size() == T->getNumElements() &&
+         "Invalid initializer for constant array");
+}
+
+Constant *ConstantArray::get(ArrayType *Ty, ArrayRef<Constant*> V) {
+  if (Constant *C = getImpl(Ty, V))
+    return C;
+  return Ty->getContext().pImpl->ArrayConstants.getOrCreate(Ty, V);
+}
+
+Constant *ConstantArray::getImpl(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");
+  }
+
+  // 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()))
+    return getSequenceIfElementsMatch<ConstantDataArray>(C, V);
+
+  // Otherwise, we really do want to create a ConstantArray.
+  return nullptr;
+}
+
+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)
+    : ConstantAggregate(T, ConstantStructVal, V) {
+  assert((T->isOpaque() || V.size() == T->getNumElements()) &&
+         "Invalid initializer for constant struct");
+}
+
+// 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);
+}
+
+ConstantVector::ConstantVector(VectorType *T, ArrayRef<Constant *> V)
+    : ConstantAggregate(T, ConstantVectorVal, V) {
+  assert(V.size() == cast<FixedVectorType>(T)->getNumElements() &&
+         "Invalid initializer for constant vector");
+}
+
+// ConstantVector accessors.
+Constant *ConstantVector::get(ArrayRef<Constant*> V) {
+  if (Constant *C = getImpl(V))
+    return C;
+  auto *Ty = FixedVectorType::get(V.front()->getType(), V.size());
+  return Ty->getContext().pImpl->VectorConstants.getOrCreate(Ty, V);
+}
+
+Constant *ConstantVector::getImpl(ArrayRef<Constant*> V) {
+  assert(!V.empty() && "Vectors can't be empty");
+  auto *T = FixedVectorType::get(V.front()->getType(), V.size());
+
+  // 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);
+  bool isPoison = isa<PoisonValue>(C);
+
+  if (isZero || isUndef) {
+    for (unsigned i = 1, e = V.size(); i != e; ++i)
+      if (V[i] != C) {
+        isZero = isUndef = isPoison = false;
+        break;
+      }
+  }
+
+  if (isZero)
+    return ConstantAggregateZero::get(T);
+  if (isPoison)
+    return PoisonValue::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()))
+    return getSequenceIfElementsMatch<ConstantDataVector>(C, V);
+
+  // Otherwise, the element type isn't compatible with ConstantDataVector, or
+  // the operand list contains a ConstantExpr or something else strange.
+  return nullptr;
+}
+
+Constant *ConstantVector::getSplat(ElementCount EC, Constant *V) {
+  if (!EC.isScalable()) {
+    // 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(EC.getKnownMinValue(), V);
+
+    SmallVector<Constant *, 32> Elts(EC.getKnownMinValue(), V);
+    return get(Elts);
+  }
+
+  Type *VTy = VectorType::get(V->getType(), EC);
+
+  if (V->isNullValue())
+    return ConstantAggregateZero::get(VTy);
+  else if (isa<UndefValue>(V))
+    return UndefValue::get(VTy);
+
+  Type *I32Ty = Type::getInt32Ty(VTy->getContext());
+
+  // Move scalar into vector.
+  Constant *UndefV = UndefValue::get(VTy);
+  V = ConstantExpr::getInsertElement(UndefV, V, ConstantInt::get(I32Ty, 0));
+  // Build shuffle mask to perform the splat.
+  SmallVector<int, 8> Zeros(EC.getKnownMinValue(), 0);
+  // Splat.
+  return ConstantExpr::getShuffleVector(V, UndefV, Zeros);
+}
+
+ConstantTokenNone *ConstantTokenNone::get(LLVMContext &Context) {
+  LLVMContextImpl *pImpl = Context.pImpl;
+  if (!pImpl->TheNoneToken)
+    pImpl->TheNoneToken.reset(new ConstantTokenNone(Context));
+  return pImpl->TheNoneToken.get();
+}
+
+/// Remove the constant from the constant table.
+void ConstantTokenNone::destroyConstantImpl() {
+  llvm_unreachable("You can't ConstantTokenNone->destroyConstantImpl()!");
+}
+
+// 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 = std::next(this->op_begin());
+
+  // The remaining indices may be compile-time known integers within the bounds
+  // of the corresponding notional static array types.
+  for (; GEPI != E; ++GEPI, ++OI) {
+    if (isa<UndefValue>(*OI))
+      continue;
+    auto *CI = dyn_cast<ConstantInt>(*OI);
+    if (!CI || (GEPI.isBoundedSequential() &&
+                (CI->getValue().getActiveBits() > 64 ||
+                 CI->getZExtValue() >= GEPI.getSequentialNumElements())))
+      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 {
+  return cast<CompareConstantExpr>(this)->predicate;
+}
+
+ArrayRef<int> ConstantExpr::getShuffleMask() const {
+  return cast<ShuffleVectorConstantExpr>(this)->ShuffleMask;
+}
+
+Constant *ConstantExpr::getShuffleMaskForBitcode() const {
+  return cast<ShuffleVectorConstantExpr>(this)->ShuffleMaskForBitcode;
+}
+
+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);
+}
+
+Constant *ConstantExpr::getWithOperands(ArrayRef<Constant *> Ops, Type *Ty,
+                                        bool OnlyIfReduced, Type *SrcTy) const {
+  assert(Ops.size() == getNumOperands() && "Operand count mismatch!");
+
+  // If no operands changed return self.
+  if (Ty == getType() && std::equal(Ops.begin(), Ops.end(), op_begin()))
+    return const_cast<ConstantExpr*>(this);
+
+  Type *OnlyIfReducedTy = OnlyIfReduced ? Ty : nullptr;
+  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:
+  case Instruction::AddrSpaceCast:
+    return ConstantExpr::getCast(getOpcode(), Ops[0], Ty, OnlyIfReduced);
+  case Instruction::Select:
+    return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2], OnlyIfReducedTy);
+  case Instruction::InsertElement:
+    return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2],
+                                          OnlyIfReducedTy);
+  case Instruction::ExtractElement:
+    return ConstantExpr::getExtractElement(Ops[0], Ops[1], OnlyIfReducedTy);
+  case Instruction::InsertValue:
+    return ConstantExpr::getInsertValue(Ops[0], Ops[1], getIndices(),
+                                        OnlyIfReducedTy);
+  case Instruction::ExtractValue:
+    return ConstantExpr::getExtractValue(Ops[0], getIndices(), OnlyIfReducedTy);
+  case Instruction::FNeg:
+    return ConstantExpr::getFNeg(Ops[0]);
+  case Instruction::ShuffleVector:
+    return ConstantExpr::getShuffleVector(Ops[0], Ops[1], getShuffleMask(),
+                                          OnlyIfReducedTy);
+  case Instruction::GetElementPtr: {
+    auto *GEPO = cast<GEPOperator>(this);
+    assert(SrcTy || (Ops[0]->getType() == getOperand(0)->getType()));
+    return ConstantExpr::getGetElementPtr(
+        SrcTy ? SrcTy : GEPO->getSourceElementType(), Ops[0], Ops.slice(1),
+        GEPO->isInBounds(), GEPO->getInRangeIndex(), OnlyIfReducedTy);
+  }
+  case Instruction::ICmp:
+  case Instruction::FCmp:
+    return ConstantExpr::getCompare(getPredicate(), Ops[0], Ops[1],
+                                    OnlyIfReducedTy);
+  default:
+    assert(getNumOperands() == 2 && "Must be binary operator?");
+    return ConstantExpr::get(getOpcode(), Ops[0], Ops[1], SubclassOptionalData,
+                             OnlyIfReducedTy);
+  }
+}
+
+
+//===----------------------------------------------------------------------===//
+//                      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;
+  return isUIntN(NumBits, Val);
+}
+
+bool ConstantInt::isValueValidForType(Type *Ty, int64_t Val) {
+  unsigned NumBits = Ty->getIntegerBitWidth();
+  if (Ty->isIntegerTy(1))
+    return Val == 0 || Val == 1 || Val == -1;
+  return isIntN(NumBits, Val);
+}
+
+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::BFloatTyID: {
+    if (&Val2.getSemantics() == &APFloat::BFloat())
+      return true;
+    Val2.convert(APFloat::BFloat(), 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::BFloat() ||
+        &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::BFloat() ||
+           &Val2.getSemantics() == &APFloat::IEEEsingle() ||
+           &Val2.getSemantics() == &APFloat::IEEEdouble() ||
+           &Val2.getSemantics() == &APFloat::x87DoubleExtended();
+  case Type::FP128TyID:
+    return &Val2.getSemantics() == &APFloat::IEEEhalf() ||
+           &Val2.getSemantics() == &APFloat::BFloat() ||
+           &Val2.getSemantics() == &APFloat::IEEEsingle() ||
+           &Val2.getSemantics() == &APFloat::IEEEdouble() ||
+           &Val2.getSemantics() == &APFloat::IEEEquad();
+  case Type::PPC_FP128TyID:
+    return &Val2.getSemantics() == &APFloat::IEEEhalf() ||
+           &Val2.getSemantics() == &APFloat::BFloat() ||
+           &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!");
+
+  std::unique_ptr<ConstantAggregateZero> &Entry =
+      Ty->getContext().pImpl->CAZConstants[Ty];
+  if (!Entry)
+    Entry.reset(new ConstantAggregateZero(Ty));
+
+  return Entry.get();
+}
+
+/// Remove the constant from the constant table.
+void ConstantAggregateZero::destroyConstantImpl() {
+  getContext().pImpl->CAZConstants.erase(getType());
+}
+
+/// Remove the constant from the constant table.
+void ConstantArray::destroyConstantImpl() {
+  getType()->getContext().pImpl->ArrayConstants.remove(this);
+}
+
+
+//---- ConstantStruct::get() implementation...
+//
+
+/// Remove the constant from the constant table.
+void ConstantStruct::destroyConstantImpl() {
+  getType()->getContext().pImpl->StructConstants.remove(this);
+}
+
+/// Remove the constant from the constant table.
+void ConstantVector::destroyConstantImpl() {
+  getType()->getContext().pImpl->VectorConstants.remove(this);
+}
+
+Constant *Constant::getSplatValue(bool AllowUndefs) const {
+  assert(this->getType()->isVectorTy() && "Only valid for vectors!");
+  if (isa<ConstantAggregateZero>(this))
+    return getNullValue(cast<VectorType>(getType())->getElementType());
+  if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this))
+    return CV->getSplatValue();
+  if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
+    return CV->getSplatValue(AllowUndefs);
+
+  // Check if this is a constant expression splat of the form returned by
+  // ConstantVector::getSplat()
+  const auto *Shuf = dyn_cast<ConstantExpr>(this);
+  if (Shuf && Shuf->getOpcode() == Instruction::ShuffleVector &&
+      isa<UndefValue>(Shuf->getOperand(1))) {
+
+    const auto *IElt = dyn_cast<ConstantExpr>(Shuf->getOperand(0));
+    if (IElt && IElt->getOpcode() == Instruction::InsertElement &&
+        isa<UndefValue>(IElt->getOperand(0))) {
+
+      ArrayRef<int> Mask = Shuf->getShuffleMask();
+      Constant *SplatVal = IElt->getOperand(1);
+      ConstantInt *Index = dyn_cast<ConstantInt>(IElt->getOperand(2));
+
+      if (Index && Index->getValue() == 0 &&
+          llvm::all_of(Mask, [](int I) { return I == 0; }))
+        return SplatVal;
+    }
+  }
+
+  return nullptr;
+}
+
+Constant *ConstantVector::getSplatValue(bool AllowUndefs) 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) {
+    Constant *OpC = getOperand(I);
+    if (OpC == Elt)
+      continue;
+
+    // Strict mode: any mismatch is not a splat.
+    if (!AllowUndefs)
+      return nullptr;
+
+    // Allow undefs mode: ignore undefined elements.
+    if (isa<UndefValue>(OpC))
+      continue;
+
+    // If we do not have a defined element yet, use the current operand.
+    if (isa<UndefValue>(Elt))
+      Elt = OpC;
+
+    if (OpC != Elt)
+      return nullptr;
+  }
+  return Elt;
+}
+
+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) {
+  std::unique_ptr<ConstantPointerNull> &Entry =
+      Ty->getContext().pImpl->CPNConstants[Ty];
+  if (!Entry)
+    Entry.reset(new ConstantPointerNull(Ty));
+
+  return Entry.get();
+}
+
+/// Remove the constant from the constant table.
+void ConstantPointerNull::destroyConstantImpl() {
+  getContext().pImpl->CPNConstants.erase(getType());
+}
+
+UndefValue *UndefValue::get(Type *Ty) {
+  std::unique_ptr<UndefValue> &Entry = Ty->getContext().pImpl->UVConstants[Ty];
+  if (!Entry)
+    Entry.reset(new UndefValue(Ty));
+
+  return Entry.get();
+}
+
+/// Remove the constant from the constant table.
+void UndefValue::destroyConstantImpl() {
+  // Free the constant and any dangling references to it.
+  if (getValueID() == UndefValueVal) {
+    getContext().pImpl->UVConstants.erase(getType());
+  } else if (getValueID() == PoisonValueVal) {
+    getContext().pImpl->PVConstants.erase(getType());
+  }
+  llvm_unreachable("Not a undef or a poison!");
+}
+
+PoisonValue *PoisonValue::get(Type *Ty) {
+  std::unique_ptr<PoisonValue> &Entry = Ty->getContext().pImpl->PVConstants[Ty];
+  if (!Entry)
+    Entry.reset(new PoisonValue(Ty));
+
+  return Entry.get();
+}
+
+/// Remove the constant from the constant table.
+void PoisonValue::destroyConstantImpl() {
+  // Free the constant and any dangling references to it.
+  getContext().pImpl->PVConstants.erase(getType());
+}
+
+BlockAddress *BlockAddress::get(BasicBlock *BB) {
+  assert(BB->getParent() && "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)
+    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);
+}
+
+BlockAddress *BlockAddress::lookup(const BasicBlock *BB) {
+  if (!BB->hasAddressTaken())
+    return nullptr;
+
+  const Function *F = BB->getParent();
+  assert(F && "Block must have a parent");
+  BlockAddress *BA =
+      F->getContext().pImpl->BlockAddresses.lookup(std::make_pair(F, BB));
+  assert(BA && "Refcount and block address map disagree!");
+  return BA;
+}
+
+/// Remove the constant from the constant table.
+void BlockAddress::destroyConstantImpl() {
+  getFunction()->getType()->getContext().pImpl
+    ->BlockAddresses.erase(std::make_pair(getFunction(), getBasicBlock()));
+  getBasicBlock()->AdjustBlockAddressRefCount(-1);
+}
+
+Value *BlockAddress::handleOperandChangeImpl(Value *From, Value *To) {
+  // 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 (From == NewF)
+    NewF = cast<Function>(To->stripPointerCasts());
+  else {
+    assert(From == NewBB && "From does not match any operand");
+    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)
+    return NewBA;
+
+  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);
+
+  // If we just want to keep the existing value, then return null.
+  // Callers know that this means we shouldn't delete this value.
+  return nullptr;
+}
+
+DSOLocalEquivalent *DSOLocalEquivalent::get(GlobalValue *GV) {
+  DSOLocalEquivalent *&Equiv = GV->getContext().pImpl->DSOLocalEquivalents[GV];
+  if (!Equiv)
+    Equiv = new DSOLocalEquivalent(GV);
+
+  assert(Equiv->getGlobalValue() == GV &&
+         "DSOLocalFunction does not match the expected global value");
+  return Equiv;
+}
+
+DSOLocalEquivalent::DSOLocalEquivalent(GlobalValue *GV)
+    : Constant(GV->getType(), Value::DSOLocalEquivalentVal, &Op<0>(), 1) {
+  setOperand(0, GV);
+}
+
+/// Remove the constant from the constant table.
+void DSOLocalEquivalent::destroyConstantImpl() {
+  const GlobalValue *GV = getGlobalValue();
+  GV->getContext().pImpl->DSOLocalEquivalents.erase(GV);
+}
+
+Value *DSOLocalEquivalent::handleOperandChangeImpl(Value *From, Value *To) {
+  assert(From == getGlobalValue() && "Changing value does not match operand.");
+  assert(isa<Constant>(To) && "Can only replace the operands with a constant");
+
+  // The replacement is with another global value.
+  if (const auto *ToObj = dyn_cast<GlobalValue>(To)) {
+    DSOLocalEquivalent *&NewEquiv =
+        getContext().pImpl->DSOLocalEquivalents[ToObj];
+    if (NewEquiv)
+      return llvm::ConstantExpr::getBitCast(NewEquiv, getType());
+  }
+
+  // If the argument is replaced with a null value, just replace this constant
+  // with a null value.
+  if (cast<Constant>(To)->isNullValue())
+    return To;
+
+  // The replacement could be a bitcast or an alias to another function. We can
+  // replace it with a bitcast to the dso_local_equivalent of that function.
+  auto *Func = cast<Function>(To->stripPointerCastsAndAliases());
+  DSOLocalEquivalent *&NewEquiv = getContext().pImpl->DSOLocalEquivalents[Func];
+  if (NewEquiv)
+    return llvm::ConstantExpr::getBitCast(NewEquiv, getType());
+
+  // Replace this with the new one.
+  getContext().pImpl->DSOLocalEquivalents.erase(getGlobalValue());
+  NewEquiv = this;
+  setOperand(0, Func);
+  return nullptr;
+}
+
+//---- 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 Constant *getFoldedCast(Instruction::CastOps opc, Constant *C, Type *Ty,
+                               bool OnlyIfReduced = false) {
+  assert(Ty->isFirstClassType() && "Cannot cast to an aggregate type!");
+  // Fold a few common cases
+  if (Constant *FC = ConstantFoldCastInstruction(opc, C, Ty))
+    return FC;
+
+  if (OnlyIfReduced)
+    return nullptr;
+
+  LLVMContextImpl *pImpl = Ty->getContext().pImpl;
+
+  // Look up the constant in the table first to ensure uniqueness.
+  ConstantExprKeyType Key(opc, C);
+
+  return pImpl->ExprConstants.getOrCreate(Ty, Key);
+}
+
+Constant *ConstantExpr::getCast(unsigned oc, Constant *C, Type *Ty,
+                                bool OnlyIfReduced) {
+  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, OnlyIfReduced);
+  case Instruction::ZExt:
+    return getZExt(C, Ty, OnlyIfReduced);
+  case Instruction::SExt:
+    return getSExt(C, Ty, OnlyIfReduced);
+  case Instruction::FPTrunc:
+    return getFPTrunc(C, Ty, OnlyIfReduced);
+  case Instruction::FPExt:
+    return getFPExtend(C, Ty, OnlyIfReduced);
+  case Instruction::UIToFP:
+    return getUIToFP(C, Ty, OnlyIfReduced);
+  case Instruction::SIToFP:
+    return getSIToFP(C, Ty, OnlyIfReduced);
+  case Instruction::FPToUI:
+    return getFPToUI(C, Ty, OnlyIfReduced);
+  case Instruction::FPToSI:
+    return getFPToSI(C, Ty, OnlyIfReduced);
+  case Instruction::PtrToInt:
+    return getPtrToInt(C, Ty, OnlyIfReduced);
+  case Instruction::IntToPtr:
+    return getIntToPtr(C, Ty, OnlyIfReduced);
+  case Instruction::BitCast:
+    return getBitCast(C, Ty, OnlyIfReduced);
+  case Instruction::AddrSpaceCast:
+    return getAddrSpaceCast(C, Ty, OnlyIfReduced);
+  }
+}
+
+Constant *ConstantExpr::getZExtOrBitCast(Constant *C, Type *Ty) {
+  if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
+    return getBitCast(C, Ty);
+  return getZExt(C, Ty);
+}
+
+Constant *ConstantExpr::getSExtOrBitCast(Constant *C, Type *Ty) {
+  if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
+    return getBitCast(C, Ty);
+  return getSExt(C, Ty);
+}
+
+Constant *ConstantExpr::getTruncOrBitCast(Constant *C, Type *Ty) {
+  if (C->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
+    return getBitCast(C, Ty);
+  return getTrunc(C, Ty);
+}
+
+Constant *ConstantExpr::getPointerCast(Constant *S, Type *Ty) {
+  assert(S->getType()->isPtrOrPtrVectorTy() && "Invalid cast");
+  assert((Ty->isIntOrIntVectorTy() || Ty->isPtrOrPtrVectorTy()) &&
+          "Invalid cast");
+
+  if (Ty->isIntOrIntVectorTy())
+    return getPtrToInt(S, Ty);
+
+  unsigned SrcAS = S->getType()->getPointerAddressSpace();
+  if (Ty->isPtrOrPtrVectorTy() && SrcAS != Ty->getPointerAddressSpace())
+    return getAddrSpaceCast(S, Ty);
+
+  return getBitCast(S, Ty);
+}
+
+Constant *ConstantExpr::getPointerBitCastOrAddrSpaceCast(Constant *S,
+                                                         Type *Ty) {
+  assert(S->getType()->isPtrOrPtrVectorTy() && "Invalid cast");
+  assert(Ty->isPtrOrPtrVectorTy() && "Invalid cast");
+
+  if (S->getType()->getPointerAddressSpace() != Ty->getPointerAddressSpace())
+    return getAddrSpaceCast(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, bool OnlyIfReduced) {
+#ifndef NDEBUG
+  bool fromVec = isa<VectorType>(C->getType());
+  bool toVec = isa<VectorType>(Ty);
+#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, OnlyIfReduced);
+}
+
+Constant *ConstantExpr::getSExt(Constant *C, Type *Ty, bool OnlyIfReduced) {
+#ifndef NDEBUG
+  bool fromVec = isa<VectorType>(C->getType());
+  bool toVec = isa<VectorType>(Ty);
+#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, OnlyIfReduced);
+}
+
+Constant *ConstantExpr::getZExt(Constant *C, Type *Ty, bool OnlyIfReduced) {
+#ifndef NDEBUG
+  bool fromVec = isa<VectorType>(C->getType());
+  bool toVec = isa<VectorType>(Ty);
+#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, OnlyIfReduced);
+}
+
+Constant *ConstantExpr::getFPTrunc(Constant *C, Type *Ty, bool OnlyIfReduced) {
+#ifndef NDEBUG
+  bool fromVec = isa<VectorType>(C->getType());
+  bool toVec = isa<VectorType>(Ty);
+#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, OnlyIfReduced);
+}
+
+Constant *ConstantExpr::getFPExtend(Constant *C, Type *Ty, bool OnlyIfReduced) {
+#ifndef NDEBUG
+  bool fromVec = isa<VectorType>(C->getType());
+  bool toVec = isa<VectorType>(Ty);
+#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, OnlyIfReduced);
+}
+
+Constant *ConstantExpr::getUIToFP(Constant *C, Type *Ty, bool OnlyIfReduced) {
+#ifndef NDEBUG
+  bool fromVec = isa<VectorType>(C->getType());
+  bool toVec = isa<VectorType>(Ty);
+#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, OnlyIfReduced);
+}
+
+Constant *ConstantExpr::getSIToFP(Constant *C, Type *Ty, bool OnlyIfReduced) {
+#ifndef NDEBUG
+  bool fromVec = isa<VectorType>(C->getType());
+  bool toVec = isa<VectorType>(Ty);
+#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, OnlyIfReduced);
+}
+
+Constant *ConstantExpr::getFPToUI(Constant *C, Type *Ty, bool OnlyIfReduced) {
+#ifndef NDEBUG
+  bool fromVec = isa<VectorType>(C->getType());
+  bool toVec = isa<VectorType>(Ty);
+#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, OnlyIfReduced);
+}
+
+Constant *ConstantExpr::getFPToSI(Constant *C, Type *Ty, bool OnlyIfReduced) {
+#ifndef NDEBUG
+  bool fromVec = isa<VectorType>(C->getType());
+  bool toVec = isa<VectorType>(Ty);
+#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, OnlyIfReduced);
+}
+
+Constant *ConstantExpr::getPtrToInt(Constant *C, Type *DstTy,
+                                    bool OnlyIfReduced) {
+  assert(C->getType()->isPtrOrPtrVectorTy() &&
+         "PtrToInt source must be pointer or pointer vector");
+  assert(DstTy->isIntOrIntVectorTy() &&
+         "PtrToInt destination must be integer or integer vector");
+  assert(isa<VectorType>(C->getType()) == isa<VectorType>(DstTy));
+  if (isa<VectorType>(C->getType()))
+    assert(cast<FixedVectorType>(C->getType())->getNumElements() ==
+               cast<FixedVectorType>(DstTy)->getNumElements() &&
+           "Invalid cast between a different number of vector elements");
+  return getFoldedCast(Instruction::PtrToInt, C, DstTy, OnlyIfReduced);
+}
+
+Constant *ConstantExpr::getIntToPtr(Constant *C, Type *DstTy,
+                                    bool OnlyIfReduced) {
+  assert(C->getType()->isIntOrIntVectorTy() &&
+         "IntToPtr source must be integer or integer vector");
+  assert(DstTy->isPtrOrPtrVectorTy() &&
+         "IntToPtr destination must be a pointer or pointer vector");
+  assert(isa<VectorType>(C->getType()) == isa<VectorType>(DstTy));
+  if (isa<VectorType>(C->getType()))
+    assert(cast<VectorType>(C->getType())->getElementCount() ==
+               cast<VectorType>(DstTy)->getElementCount() &&
+           "Invalid cast between a different number of vector elements");
+  return getFoldedCast(Instruction::IntToPtr, C, DstTy, OnlyIfReduced);
+}
+
+Constant *ConstantExpr::getBitCast(Constant *C, Type *DstTy,
+                                   bool OnlyIfReduced) {
+  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, OnlyIfReduced);
+}
+
+Constant *ConstantExpr::getAddrSpaceCast(Constant *C, Type *DstTy,
+                                         bool OnlyIfReduced) {
+  assert(CastInst::castIsValid(Instruction::AddrSpaceCast, C, DstTy) &&
+         "Invalid constantexpr addrspacecast!");
+
+  // Canonicalize addrspacecasts between different pointer types by first
+  // bitcasting the pointer type and then converting the address space.
+  PointerType *SrcScalarTy = cast<PointerType>(C->getType()->getScalarType());
+  PointerType *DstScalarTy = cast<PointerType>(DstTy->getScalarType());
+  Type *DstElemTy = DstScalarTy->getElementType();
+  if (SrcScalarTy->getElementType() != DstElemTy) {
+    Type *MidTy = PointerType::get(DstElemTy, SrcScalarTy->getAddressSpace());
+    if (VectorType *VT = dyn_cast<VectorType>(DstTy)) {
+      // Handle vectors of pointers.
+      MidTy = FixedVectorType::get(MidTy,
+                                   cast<FixedVectorType>(VT)->getNumElements());
+    }
+    C = getBitCast(C, MidTy);
+  }
+  return getFoldedCast(Instruction::AddrSpaceCast, C, DstTy, OnlyIfReduced);
+}
+
+Constant *ConstantExpr::get(unsigned Opcode, Constant *C, unsigned Flags,
+                            Type *OnlyIfReducedTy) {
+  // Check the operands for consistency first.
+  assert(Instruction::isUnaryOp(Opcode) &&
+         "Invalid opcode in unary constant expression");
+
+#ifndef NDEBUG
+  switch (Opcode) {
+  case Instruction::FNeg:
+    assert(C->getType()->isFPOrFPVectorTy() &&
+           "Tried to create a floating-point operation on a "
+           "non-floating-point type!");
+    break;
+  default:
+    break;
+  }
+#endif
+
+  if (Constant *FC = ConstantFoldUnaryInstruction(Opcode, C))
+    return FC;
+
+  if (OnlyIfReducedTy == C->getType())
+    return nullptr;
+
+  Constant *ArgVec[] = { C };
+  ConstantExprKeyType Key(Opcode, ArgVec, 0, Flags);
+
+  LLVMContextImpl *pImpl = C->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(C->getType(), Key);
+}
+
+Constant *ConstantExpr::get(unsigned Opcode, Constant *C1, Constant *C2,
+                            unsigned Flags, Type *OnlyIfReducedTy) {
+  // Check the operands for consistency first.
+  assert(Instruction::isBinaryOp(Opcode) &&
+         "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:
+  case Instruction::UDiv:
+  case Instruction::SDiv:
+  case Instruction::URem:
+  case Instruction::SRem:
+    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:
+  case Instruction::FDiv:
+  case Instruction::FRem:
+    assert(C1->getType()->isFPOrFPVectorTy() &&
+           "Tried to create a floating-point operation on a "
+           "non-floating-point type!");
+    break;
+  case Instruction::And:
+  case Instruction::Or:
+  case Instruction::Xor:
+    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()->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;
+
+  if (OnlyIfReducedTy == C1->getType())
+    return nullptr;
+
+  Constant *ArgVec[] = { C1, C2 };
+  ConstantExprKeyType 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(
+      Ty, 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);
+  Constant *NullPtr = Constant::getNullValue(AligningTy->getPointerTo(0));
+  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(AligningTy, 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(
+      Ty, Constant::getNullValue(PointerType::getUnqual(Ty)), GEPIdx);
+  return getPtrToInt(GEP,
+                     Type::getInt64Ty(Ty->getContext()));
+}
+
+Constant *ConstantExpr::getCompare(unsigned short Predicate, Constant *C1,
+                                   Constant *C2, bool OnlyIfReduced) {
+  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, OnlyIfReduced);
+
+  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, OnlyIfReduced);
+  }
+}
+
+Constant *ConstantExpr::getSelect(Constant *C, Constant *V1, Constant *V2,
+                                  Type *OnlyIfReducedTy) {
+  assert(!SelectInst::areInvalidOperands(C, V1, V2)&&"Invalid select operands");
+
+  if (Constant *SC = ConstantFoldSelectInstruction(C, V1, V2))
+    return SC;        // Fold common cases
+
+  if (OnlyIfReducedTy == V1->getType())
+    return nullptr;
+
+  Constant *ArgVec[] = { C, V1, V2 };
+  ConstantExprKeyType Key(Instruction::Select, ArgVec);
+
+  LLVMContextImpl *pImpl = C->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(V1->getType(), Key);
+}
+
+Constant *ConstantExpr::getGetElementPtr(Type *Ty, Constant *C,
+                                         ArrayRef<Value *> Idxs, bool InBounds,
+                                         Optional<unsigned> InRangeIndex,
+                                         Type *OnlyIfReducedTy) {
+  if (!Ty)
+    Ty = cast<PointerType>(C->getType()->getScalarType())->getElementType();
+  else
+    assert(Ty ==
+           cast<PointerType>(C->getType()->getScalarType())->getElementType());
+
+  if (Constant *FC =
+          ConstantFoldGetElementPtr(Ty, C, InBounds, InRangeIndex, Idxs))
+    return FC;          // Fold a few common cases.
+
+  // Get the result type of the getelementptr!
+  Type *DestTy = GetElementPtrInst::getIndexedType(Ty, Idxs);
+  assert(DestTy && "GEP indices invalid!");
+  unsigned AS = C->getType()->getPointerAddressSpace();
+  Type *ReqTy = DestTy->getPointerTo(AS);
+
+  auto EltCount = ElementCount::getFixed(0);
+  if (VectorType *VecTy = dyn_cast<VectorType>(C->getType()))
+    EltCount = VecTy->getElementCount();
+  else
+    for (auto Idx : Idxs)
+      if (VectorType *VecTy = dyn_cast<VectorType>(Idx->getType()))
+        EltCount = VecTy->getElementCount();
+
+  if (EltCount.isNonZero())
+    ReqTy = VectorType::get(ReqTy, EltCount);
+
+  if (OnlyIfReducedTy == ReqTy)
+    return nullptr;
+
+  // Look up the constant in the table first to ensure uniqueness
+  std::vector<Constant*> ArgVec;
+  ArgVec.reserve(1 + Idxs.size());
+  ArgVec.push_back(C);
+  auto GTI = gep_type_begin(Ty, Idxs), GTE = gep_type_end(Ty, Idxs);
+  for (; GTI != GTE; ++GTI) {
+    auto *Idx = cast<Constant>(GTI.getOperand());
+    assert(
+        (!isa<VectorType>(Idx->getType()) ||
+         cast<VectorType>(Idx->getType())->getElementCount() == EltCount) &&
+        "getelementptr index type missmatch");
+
+    if (GTI.isStruct() && Idx->getType()->isVectorTy()) {
+      Idx = Idx->getSplatValue();
+    } else if (GTI.isSequential() && EltCount.isNonZero() &&
+               !Idx->getType()->isVectorTy()) {
+      Idx = ConstantVector::getSplat(EltCount, Idx);
+    }
+    ArgVec.push_back(Idx);
+  }
+
+  unsigned SubClassOptionalData = InBounds ? GEPOperator::IsInBounds : 0;
+  if (InRangeIndex && *InRangeIndex < 63)
+    SubClassOptionalData |= (*InRangeIndex + 1) << 1;
+  const ConstantExprKeyType Key(Instruction::GetElementPtr, ArgVec, 0,
+                                SubClassOptionalData, None, None, Ty);
+
+  LLVMContextImpl *pImpl = C->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
+}
+
+Constant *ConstantExpr::getICmp(unsigned short pred, Constant *LHS,
+                                Constant *RHS, bool OnlyIfReduced) {
+  assert(LHS->getType() == RHS->getType());
+  assert(CmpInst::isIntPredicate((CmpInst::Predicate)pred) &&
+         "Invalid ICmp Predicate");
+
+  if (Constant *FC = ConstantFoldCompareInstruction(pred, LHS, RHS))
+    return FC;          // Fold a few common cases...
+
+  if (OnlyIfReduced)
+    return nullptr;
+
+  // Look up the constant in the table first to ensure uniqueness
+  Constant *ArgVec[] = { LHS, RHS };
+  // Get the key type with both the opcode and predicate
+  const ConstantExprKeyType Key(Instruction::ICmp, ArgVec, pred);
+
+  Type *ResultTy = Type::getInt1Ty(LHS->getContext());
+  if (VectorType *VT = dyn_cast<VectorType>(LHS->getType()))
+    ResultTy = VectorType::get(ResultTy, VT->getElementCount());
+
+  LLVMContextImpl *pImpl = LHS->getType()->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(ResultTy, Key);
+}
+
+Constant *ConstantExpr::getFCmp(unsigned short pred, Constant *LHS,
+                                Constant *RHS, bool OnlyIfReduced) {
+  assert(LHS->getType() == RHS->getType());
+  assert(CmpInst::isFPPredicate((CmpInst::Predicate)pred) &&
+         "Invalid FCmp Predicate");
+
+  if (Constant *FC = ConstantFoldCompareInstruction(pred, LHS, RHS))
+    return FC;          // Fold a few common cases...
+
+  if (OnlyIfReduced)
+    return nullptr;
+
+  // Look up the constant in the table first to ensure uniqueness
+  Constant *ArgVec[] = { LHS, RHS };
+  // Get the key type with both the opcode and predicate
+  const ConstantExprKeyType Key(Instruction::FCmp, ArgVec, pred);
+
+  Type *ResultTy = Type::getInt1Ty(LHS->getContext());
+  if (VectorType *VT = dyn_cast<VectorType>(LHS->getType()))
+    ResultTy = VectorType::get(ResultTy, VT->getElementCount());
+
+  LLVMContextImpl *pImpl = LHS->getType()->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(ResultTy, Key);
+}
+
+Constant *ConstantExpr::getExtractElement(Constant *Val, Constant *Idx,
+                                          Type *OnlyIfReducedTy) {
+  assert(Val->getType()->isVectorTy() &&
+         "Tried to create extractelement operation on non-vector type!");
+  assert(Idx->getType()->isIntegerTy() &&
+         "Extractelement index must be an integer type!");
+
+  if (Constant *FC = ConstantFoldExtractElementInstruction(Val, Idx))
+    return FC;          // Fold a few common cases.
+
+  Type *ReqTy = cast<VectorType>(Val->getType())->getElementType();
+  if (OnlyIfReducedTy == ReqTy)
+    return nullptr;
+
+  // Look up the constant in the table first to ensure uniqueness
+  Constant *ArgVec[] = { Val, Idx };
+  const ConstantExprKeyType Key(Instruction::ExtractElement, ArgVec);
+
+  LLVMContextImpl *pImpl = Val->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
+}
+
+Constant *ConstantExpr::getInsertElement(Constant *Val, Constant *Elt,
+                                         Constant *Idx, Type *OnlyIfReducedTy) {
+  assert(Val->getType()->isVectorTy() &&
+         "Tried to create insertelement operation on non-vector type!");
+  assert(Elt->getType() == cast<VectorType>(Val->getType())->getElementType() &&
+         "Insertelement types must match!");
+  assert(Idx->getType()->isIntegerTy() &&
+         "Insertelement index must be i32 type!");
+
+  if (Constant *FC = ConstantFoldInsertElementInstruction(Val, Elt, Idx))
+    return FC;          // Fold a few common cases.
+
+  if (OnlyIfReducedTy == Val->getType())
+    return nullptr;
+
+  // Look up the constant in the table first to ensure uniqueness
+  Constant *ArgVec[] = { Val, Elt, Idx };
+  const ConstantExprKeyType Key(Instruction::InsertElement, ArgVec);
+
+  LLVMContextImpl *pImpl = Val->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(Val->getType(), Key);
+}
+
+Constant *ConstantExpr::getShuffleVector(Constant *V1, Constant *V2,
+                                         ArrayRef<int> Mask,
+                                         Type *OnlyIfReducedTy) {
+  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.size();
+  auto V1VTy = cast<VectorType>(V1->getType());
+  Type *EltTy = V1VTy->getElementType();
+  bool TypeIsScalable = isa<ScalableVectorType>(V1VTy);
+  Type *ShufTy = VectorType::get(EltTy, NElts, TypeIsScalable);
+
+  if (OnlyIfReducedTy == ShufTy)
+    return nullptr;
+
+  // Look up the constant in the table first to ensure uniqueness
+  Constant *ArgVec[] = {V1, V2};
+  ConstantExprKeyType Key(Instruction::ShuffleVector, ArgVec, 0, 0, None, Mask);
+
+  LLVMContextImpl *pImpl = ShufTy->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(ShufTy, Key);
+}
+
+Constant *ConstantExpr::getInsertValue(Constant *Agg, Constant *Val,
+                                       ArrayRef<unsigned> Idxs,
+                                       Type *OnlyIfReducedTy) {
+  assert(Agg->getType()->isFirstClassType() &&
+         "Non-first-class type for constant insertvalue expression");
+
+  assert(ExtractValueInst::getIndexedType(Agg->getType(),
+                                          Idxs) == Val->getType() &&
+         "insertvalue indices invalid!");
+  Type *ReqTy = Val->getType();
+
+  if (Constant *FC = ConstantFoldInsertValueInstruction(Agg, Val, Idxs))
+    return FC;
+
+  if (OnlyIfReducedTy == ReqTy)
+    return nullptr;
+
+  Constant *ArgVec[] = { Agg, Val };
+  const ConstantExprKeyType Key(Instruction::InsertValue, ArgVec, 0, 0, Idxs);
+
+  LLVMContextImpl *pImpl = Agg->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
+}
+
+Constant *ConstantExpr::getExtractValue(Constant *Agg, ArrayRef<unsigned> Idxs,
+                                        Type *OnlyIfReducedTy) {
+  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");
+  if (Constant *FC = ConstantFoldExtractValueInstruction(Agg, Idxs))
+    return FC;
+
+  if (OnlyIfReducedTy == ReqTy)
+    return nullptr;
+
+  Constant *ArgVec[] = { Agg };
+  const ConstantExprKeyType Key(Instruction::ExtractValue, ArgVec, 0, 0, Idxs);
+
+  LLVMContextImpl *pImpl = Agg->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
+}
+
+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 get(Instruction::FNeg, 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::getUMin(Constant *C1, Constant *C2) {
+  Constant *Cmp = ConstantExpr::getICmp(CmpInst::ICMP_ULT, C1, C2);
+  return getSelect(Cmp, 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);
+}
+
+Constant *ConstantExpr::getExactLogBase2(Constant *C) {
+  Type *Ty = C->getType();
+  const APInt *IVal;
+  if (match(C, m_APInt(IVal)) && IVal->isPowerOf2())
+    return ConstantInt::get(Ty, IVal->logBase2());
+
+  // FIXME: We can extract pow of 2 of splat constant for scalable vectors.
+  auto *VecTy = dyn_cast<FixedVectorType>(Ty);
+  if (!VecTy)
+    return nullptr;
+
+  SmallVector<Constant *, 4> Elts;
+  for (unsigned I = 0, E = VecTy->getNumElements(); I != E; ++I) {
+    Constant *Elt = C->getAggregateElement(I);
+    if (!Elt)
+      return nullptr;
+    // Note that log2(iN undef) is *NOT* iN undef, because log2(iN undef) u< N.
+    if (isa<UndefValue>(Elt)) {
+      Elts.push_back(Constant::getNullValue(Ty->getScalarType()));
+      continue;
+    }
+    if (!match(Elt, m_APInt(IVal)) || !IVal->isPowerOf2())
+      return nullptr;
+    Elts.push_back(ConstantInt::get(Ty->getScalarType(), IVal->logBase2()));
+  }
+
+  return ConstantVector::get(Elts);
+}
+
+Constant *ConstantExpr::getBinOpIdentity(unsigned Opcode, Type *Ty,
+                                         bool AllowRHSConstant) {
+  assert(Instruction::isBinaryOp(Opcode) && "Only binops allowed");
+
+  // Commutative opcodes: it does not matter if AllowRHSConstant is set.
+  if (Instruction::isCommutative(Opcode)) {
+    switch (Opcode) {
+      case Instruction::Add: // X + 0 = X
+      case Instruction::Or:  // X | 0 = X
+      case Instruction::Xor: // X ^ 0 = X
+        return Constant::getNullValue(Ty);
+      case Instruction::Mul: // X * 1 = X
+        return ConstantInt::get(Ty, 1);
+      case Instruction::And: // X & -1 = X
+        return Constant::getAllOnesValue(Ty);
+      case Instruction::FAdd: // X + -0.0 = X
+        // TODO: If the fadd has 'nsz', should we return +0.0?
+        return ConstantFP::getNegativeZero(Ty);
+      case Instruction::FMul: // X * 1.0 = X
+        return ConstantFP::get(Ty, 1.0);
+      default:
+        llvm_unreachable("Every commutative binop has an identity constant");
+    }
+  }
+
+  // Non-commutative opcodes: AllowRHSConstant must be set.
+  if (!AllowRHSConstant)
+    return nullptr;
+
+  switch (Opcode) {
+    case Instruction::Sub:  // X - 0 = X
+    case Instruction::Shl:  // X << 0 = X
+    case Instruction::LShr: // X >>u 0 = X
+    case Instruction::AShr: // X >> 0 = X
+    case Instruction::FSub: // X - 0.0 = X
+      return Constant::getNullValue(Ty);
+    case Instruction::SDiv: // X / 1 = X
+    case Instruction::UDiv: // X /u 1 = X
+      return ConstantInt::get(Ty, 1);
+    case Instruction::FDiv: // X / 1.0 = X
+      return ConstantFP::get(Ty, 1.0);
+    default:
+      return nullptr;
+  }
+}
+
+Constant *ConstantExpr::getBinOpAbsorber(unsigned Opcode, Type *Ty) {
+  switch (Opcode) {
+  default:
+    // Doesn't have an absorber.
+    return nullptr;
+
+  case Instruction::Or:
+    return Constant::getAllOnesValue(Ty);
+
+  case Instruction::And:
+  case Instruction::Mul:
+    return Constant::getNullValue(Ty);
+  }
+}
+
+/// Remove the constant from the constant table.
+void ConstantExpr::destroyConstantImpl() {
+  getType()->getContext().pImpl->ExprConstants.remove(this);
+}
+
+const char *ConstantExpr::getOpcodeName() const {
+  return Instruction::getOpcodeName(getOpcode());
+}
+
+GetElementPtrConstantExpr::GetElementPtrConstantExpr(
+    Type *SrcElementTy, Constant *C, ArrayRef<Constant *> IdxList, Type *DestTy)
+    : ConstantExpr(DestTy, Instruction::GetElementPtr,
+                   OperandTraits<GetElementPtrConstantExpr>::op_end(this) -
+                       (IdxList.size() + 1),
+                   IdxList.size() + 1),
+      SrcElementTy(SrcElementTy),
+      ResElementTy(GetElementPtrInst::getIndexedType(SrcElementTy, IdxList)) {
+  Op<0>() = C;
+  Use *OperandList = getOperandList();
+  for (unsigned i = 0, E = IdxList.size(); i != E; ++i)
+    OperandList[i+1] = IdxList[i];
+}
+
+Type *GetElementPtrConstantExpr::getSourceElementType() const {
+  return SrcElementTy;
+}
+
+Type *GetElementPtrConstantExpr::getResultElementType() const {
+  return ResElementTy;
+}
+
+//===----------------------------------------------------------------------===//
+//                       ConstantData* implementations
+
+Type *ConstantDataSequential::getElementType() const {
+  if (ArrayType *ATy = dyn_cast<ArrayType>(getType()))
+    return ATy->getElementType();
+  return cast<VectorType>(getType())->getElementType();
+}
+
+StringRef ConstantDataSequential::getRawDataValues() const {
+  return StringRef(DataElements, getNumElements()*getElementByteSize());
+}
+
+bool ConstantDataSequential::isElementTypeCompatible(Type *Ty) {
+  if (Ty->isHalfTy() || Ty->isBFloatTy() || Ty->isFloatTy() || Ty->isDoubleTy())
+    return true;
+  if (auto *IT = dyn_cast<IntegerType>(Ty)) {
+    switch (IT->getBitWidth()) {
+    case 8:
+    case 16:
+    case 32:
+    case 64:
+      return true;
+    default: break;
+    }
+  }
+  return false;
+}
+
+unsigned ConstantDataSequential::getNumElements() const {
+  if (ArrayType *AT = dyn_cast<ArrayType>(getType()))
+    return AT->getNumElements();
+  return cast<FixedVectorType>(getType())->getNumElements();
+}
+
+
+uint64_t ConstantDataSequential::getElementByteSize() const {
+  return getElementType()->getPrimitiveSizeInBits()/8;
+}
+
+/// Return the start of the specified element.
+const char *ConstantDataSequential::getElementPointer(unsigned Elt) const {
+  assert(Elt < getNumElements() && "Invalid Elt");
+  return DataElements+Elt*getElementByteSize();
+}
+
+
+/// Return true if the array is empty or all zeros.
+static bool isAllZeros(StringRef Arr) {
+  for (char I : Arr)
+    if (I != 0)
+      return false;
+  return true;
+}
+
+/// 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) {
+#ifndef NDEBUG
+  if (ArrayType *ATy = dyn_cast<ArrayType>(Ty))
+    assert(isElementTypeCompatible(ATy->getElementType()));
+  else
+    assert(isElementTypeCompatible(cast<VectorType>(Ty)->getElementType()));
+#endif
+  // 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.
+  auto &Slot =
+      *Ty->getContext()
+           .pImpl->CDSConstants.insert(std::make_pair(Elements, nullptr))
+           .first;
+
+  // 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.
+  std::unique_ptr<ConstantDataSequential> *Entry = &Slot.second;
+  for (; *Entry; Entry = &(*Entry)->Next)
+    if ((*Entry)->getType() == Ty)
+      return Entry->get();
+
+  // Okay, we didn't get a hit.  Create a node of the right class, link it in,
+  // and return it.
+  if (isa<ArrayType>(Ty)) {
+    // Use reset because std::make_unique can't access the constructor.
+    Entry->reset(new ConstantDataArray(Ty, Slot.first().data()));
+    return Entry->get();
+  }
+
+  assert(isa<VectorType>(Ty));
+  // Use reset because std::make_unique can't access the constructor.
+  Entry->reset(new ConstantDataVector(Ty, Slot.first().data()));
+  return Entry->get();
+}
+
+void ConstantDataSequential::destroyConstantImpl() {
+  // Remove the constant from the StringMap.
+  StringMap<std::unique_ptr<ConstantDataSequential>> &CDSConstants =
+      getType()->getContext().pImpl->CDSConstants;
+
+  auto Slot = CDSConstants.find(getRawDataValues());
+
+  assert(Slot != CDSConstants.end() && "CDS not found in uniquing table");
+
+  std::unique_ptr<ConstantDataSequential> *Entry = &Slot->getValue();
+
+  // Remove the entry from the hash table.
+  if (!(*Entry)->Next) {
+    // 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->get() == this && "Hash mismatch in ConstantDataSequential");
+    getContext().pImpl->CDSConstants.erase(Slot);
+    return;
+  }
+
+  // Otherwise, there are multiple entries linked off the bucket, unlink the
+  // node we care about but keep the bucket around.
+  while (true) {
+    std::unique_ptr<ConstantDataSequential> &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.get() == this) {
+      Node = std::move(Node->Next);
+      return;
+    }
+
+    Entry = &Node->Next;
+  }
+}
+
+/// getFP() constructors - Return a constant of array type with a float
+/// element type taken from argument `ElementType', and count taken from
+/// argument `Elts'.  The amount of bits of the contained type must match the
+/// number of bits of the type contained in the passed in ArrayRef.
+/// (i.e. half or bfloat for 16bits, float for 32bits, double for 64bits) Note
+/// that this can return a ConstantAggregateZero object.
+Constant *ConstantDataArray::getFP(Type *ElementType, ArrayRef<uint16_t> Elts) {
+  assert((ElementType->isHalfTy() || ElementType->isBFloatTy()) &&
+         "Element type is not a 16-bit float type");
+  Type *Ty = ArrayType::get(ElementType, Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(Data, Elts.size() * 2), Ty);
+}
+Constant *ConstantDataArray::getFP(Type *ElementType, ArrayRef<uint32_t> Elts) {
+  assert(ElementType->isFloatTy() && "Element type is not a 32-bit float type");
+  Type *Ty = ArrayType::get(ElementType, Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(Data, Elts.size() * 4), Ty);
+}
+Constant *ConstantDataArray::getFP(Type *ElementType, ArrayRef<uint64_t> Elts) {
+  assert(ElementType->isDoubleTy() &&
+         "Element type is not a 64-bit float type");
+  Type *Ty = ArrayType::get(ElementType, Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(Data, Elts.size() * 8), Ty);
+}
+
+Constant *ConstantDataArray::getString(LLVMContext &Context,
+                                       StringRef Str, bool AddNull) {
+  if (!AddNull) {
+    const uint8_t *Data = Str.bytes_begin();
+    return get(Context, makeArrayRef(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){
+  auto *Ty = FixedVectorType::get(Type::getInt8Ty(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(Data, Elts.size() * 1), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint16_t> Elts){
+  auto *Ty = FixedVectorType::get(Type::getInt16Ty(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(Data, Elts.size() * 2), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint32_t> Elts){
+  auto *Ty = FixedVectorType::get(Type::getInt32Ty(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(Data, Elts.size() * 4), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<uint64_t> Elts){
+  auto *Ty = FixedVectorType::get(Type::getInt64Ty(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(Data, Elts.size() * 8), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<float> Elts) {
+  auto *Ty = FixedVectorType::get(Type::getFloatTy(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(Data, Elts.size() * 4), Ty);
+}
+Constant *ConstantDataVector::get(LLVMContext &Context, ArrayRef<double> Elts) {
+  auto *Ty = FixedVectorType::get(Type::getDoubleTy(Context), Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(Data, Elts.size() * 8), Ty);
+}
+
+/// getFP() constructors - Return a constant of vector type with a float
+/// element type taken from argument `ElementType', and count taken from
+/// argument `Elts'.  The amount of bits of the contained type must match the
+/// number of bits of the type contained in the passed in ArrayRef.
+/// (i.e. half or bfloat for 16bits, float for 32bits, double for 64bits) Note
+/// that this can return a ConstantAggregateZero object.
+Constant *ConstantDataVector::getFP(Type *ElementType,
+                                    ArrayRef<uint16_t> Elts) {
+  assert((ElementType->isHalfTy() || ElementType->isBFloatTy()) &&
+         "Element type is not a 16-bit float type");
+  auto *Ty = FixedVectorType::get(ElementType, Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(Data, Elts.size() * 2), Ty);
+}
+Constant *ConstantDataVector::getFP(Type *ElementType,
+                                    ArrayRef<uint32_t> Elts) {
+  assert(ElementType->isFloatTy() && "Element type is not a 32-bit float type");
+  auto *Ty = FixedVectorType::get(ElementType, Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(Data, Elts.size() * 4), Ty);
+}
+Constant *ConstantDataVector::getFP(Type *ElementType,
+                                    ArrayRef<uint64_t> Elts) {
+  assert(ElementType->isDoubleTy() &&
+         "Element type is not a 64-bit float type");
+  auto *Ty = FixedVectorType::get(ElementType, Elts.size());
+  const char *Data = reinterpret_cast<const char *>(Elts.data());
+  return getImpl(StringRef(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()->isHalfTy()) {
+      SmallVector<uint16_t, 16> Elts(
+          NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
+      return getFP(V->getType(), Elts);
+    }
+    if (CFP->getType()->isBFloatTy()) {
+      SmallVector<uint16_t, 16> Elts(
+          NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
+      return getFP(V->getType(), Elts);
+    }
+    if (CFP->getType()->isFloatTy()) {
+      SmallVector<uint32_t, 16> Elts(
+          NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
+      return getFP(V->getType(), Elts);
+    }
+    if (CFP->getType()->isDoubleTy()) {
+      SmallVector<uint64_t, 16> Elts(
+          NumElts, CFP->getValueAPF().bitcastToAPInt().getLimitedValue());
+      return getFP(V->getType(), Elts);
+    }
+  }
+  return ConstantVector::getSplat(ElementCount::getFixed(NumElts), V);
+}
+
+
+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 *reinterpret_cast<const uint8_t *>(EltPtr);
+  case 16:
+    return *reinterpret_cast<const uint16_t *>(EltPtr);
+  case 32:
+    return *reinterpret_cast<const uint32_t *>(EltPtr);
+  case 64:
+    return *reinterpret_cast<const uint64_t *>(EltPtr);
+  }
+}
+
+APInt ConstantDataSequential::getElementAsAPInt(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: {
+    auto EltVal = *reinterpret_cast<const uint8_t *>(EltPtr);
+    return APInt(8, EltVal);
+  }
+  case 16: {
+    auto EltVal = *reinterpret_cast<const uint16_t *>(EltPtr);
+    return APInt(16, EltVal);
+  }
+  case 32: {
+    auto EltVal = *reinterpret_cast<const uint32_t *>(EltPtr);
+    return APInt(32, EltVal);
+  }
+  case 64: {
+    auto EltVal = *reinterpret_cast<const uint64_t *>(EltPtr);
+    return APInt(64, EltVal);
+  }
+  }
+}
+
+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::HalfTyID: {
+    auto EltVal = *reinterpret_cast<const uint16_t *>(EltPtr);
+    return APFloat(APFloat::IEEEhalf(), APInt(16, EltVal));
+  }
+  case Type::BFloatTyID: {
+    auto EltVal = *reinterpret_cast<const uint16_t *>(EltPtr);
+    return APFloat(APFloat::BFloat(), APInt(16, EltVal));
+  }
+  case Type::FloatTyID: {
+    auto EltVal = *reinterpret_cast<const uint32_t *>(EltPtr);
+    return APFloat(APFloat::IEEEsingle(), APInt(32, EltVal));
+  }
+  case Type::DoubleTyID: {
+    auto EltVal = *reinterpret_cast<const uint64_t *>(EltPtr);
+    return APFloat(APFloat::IEEEdouble(), APInt(64, EltVal));
+  }
+  }
+}
+
+float ConstantDataSequential::getElementAsFloat(unsigned Elt) const {
+  assert(getElementType()->isFloatTy() &&
+         "Accessor can only be used when element is a 'float'");
+  return *reinterpret_cast<const float *>(getElementPointer(Elt));
+}
+
+double ConstantDataSequential::getElementAsDouble(unsigned Elt) const {
+  assert(getElementType()->isDoubleTy() &&
+         "Accessor can only be used when element is a 'float'");
+  return *reinterpret_cast<const double *>(getElementPointer(Elt));
+}
+
+Constant *ConstantDataSequential::getElementAsConstant(unsigned Elt) const {
+  if (getElementType()->isHalfTy() || getElementType()->isBFloatTy() ||
+      getElementType()->isFloatTy() || getElementType()->isDoubleTy())
+    return ConstantFP::get(getContext(), getElementAsAPFloat(Elt));
+
+  return ConstantInt::get(getElementType(), getElementAsInteger(Elt));
+}
+
+bool ConstantDataSequential::isString(unsigned CharSize) const {
+  return isa<ArrayType>(getType()) && getElementType()->isIntegerTy(CharSize);
+}
+
+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;
+}
+
+bool ConstantDataVector::isSplatData() 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 false;
+
+  return true;
+}
+
+bool ConstantDataVector::isSplat() const {
+  if (!IsSplatSet) {
+    IsSplatSet = true;
+    IsSplat = isSplatData();
+  }
+  return IsSplat;
+}
+
+Constant *ConstantDataVector::getSplatValue() const {
+  // If they're all the same, return the 0th one as a representative.
+  return isSplat() ? getElementAsConstant(0) : nullptr;
+}
+
+//===----------------------------------------------------------------------===//
+//                handleOperandChange implementations
+
+/// 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::handleOperandChange 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 Constant::handleOperandChange(Value *From, Value *To) {
+  Value *Replacement = nullptr;
+  switch (getValueID()) {
+  default:
+    llvm_unreachable("Not a constant!");
+#define HANDLE_CONSTANT(Name)                                                  \
+  case Value::Name##Val:                                                       \
+    Replacement = cast<Name>(this)->handleOperandChangeImpl(From, To);         \
+    break;
+#include "llvm/IR/Value.def"
+  }
+
+  // If handleOperandChangeImpl returned nullptr, then it handled
+  // replacing itself and we don't want to delete or replace anything else here.
+  if (!Replacement)
+    return;
+
+  // 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();
+}
+
+Value *ConstantArray::handleOperandChangeImpl(Value *From, Value *To) {
+  assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
+  Constant *ToC = cast<Constant>(To);
+
+  SmallVector<Constant*, 8> Values;
+  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;
+  Use *OperandList = getOperandList();
+  unsigned OperandNo = 0;
+  for (Use *O = OperandList, *E = OperandList+getNumOperands(); O != E; ++O) {
+    Constant *Val = cast<Constant>(O->get());
+    if (Val == From) {
+      OperandNo = (O - OperandList);
+      Val = ToC;
+      ++NumUpdated;
+    }
+    Values.push_back(Val);
+    AllSame &= Val == ToC;
+  }
+
+  if (AllSame && ToC->isNullValue())
+    return ConstantAggregateZero::get(getType());
+
+  if (AllSame && isa<UndefValue>(ToC))
+    return UndefValue::get(getType());
+
+  // Check for any other type of constant-folding.
+  if (Constant *C = getImpl(getType(), Values))
+    return C;
+
+  // Update to the new value.
+  return getContext().pImpl->ArrayConstants.replaceOperandsInPlace(
+      Values, this, From, ToC, NumUpdated, OperandNo);
+}
+
+Value *ConstantStruct::handleOperandChangeImpl(Value *From, Value *To) {
+  assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
+  Constant *ToC = cast<Constant>(To);
+
+  Use *OperandList = getOperandList();
+
+  SmallVector<Constant*, 8> Values;
+  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.
+  unsigned NumUpdated = 0;
+  bool AllSame = true;
+  unsigned OperandNo = 0;
+  for (Use *O = OperandList, *E = OperandList + getNumOperands(); O != E; ++O) {
+    Constant *Val = cast<Constant>(O->get());
+    if (Val == From) {
+      OperandNo = (O - OperandList);
+      Val = ToC;
+      ++NumUpdated;
+    }
+    Values.push_back(Val);
+    AllSame &= Val == ToC;
+  }
+
+  if (AllSame && ToC->isNullValue())
+    return ConstantAggregateZero::get(getType());
+
+  if (AllSame && isa<UndefValue>(ToC))
+    return UndefValue::get(getType());
+
+  // Update to the new value.
+  return getContext().pImpl->StructConstants.replaceOperandsInPlace(
+      Values, this, From, ToC, NumUpdated, OperandNo);
+}
+
+Value *ConstantVector::handleOperandChangeImpl(Value *From, Value *To) {
+  assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
+  Constant *ToC = cast<Constant>(To);
+
+  SmallVector<Constant*, 8> Values;
+  Values.reserve(getNumOperands());  // Build replacement array...
+  unsigned NumUpdated = 0;
+  unsigned OperandNo = 0;
+  for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
+    Constant *Val = getOperand(i);
+    if (Val == From) {
+      OperandNo = i;
+      ++NumUpdated;
+      Val = ToC;
+    }
+    Values.push_back(Val);
+  }
+
+  if (Constant *C = getImpl(Values))
+    return C;
+
+  // Update to the new value.
+  return getContext().pImpl->VectorConstants.replaceOperandsInPlace(
+      Values, this, From, ToC, NumUpdated, OperandNo);
+}
+
+Value *ConstantExpr::handleOperandChangeImpl(Value *From, Value *ToV) {
+  assert(isa<Constant>(ToV) && "Cannot make Constant refer to non-constant!");
+  Constant *To = cast<Constant>(ToV);
+
+  SmallVector<Constant*, 8> NewOps;
+  unsigned NumUpdated = 0;
+  unsigned OperandNo = 0;
+  for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
+    Constant *Op = getOperand(i);
+    if (Op == From) {
+      OperandNo = i;
+      ++NumUpdated;
+      Op = To;
+    }
+    NewOps.push_back(Op);
+  }
+  assert(NumUpdated && "I didn't contain From!");
+
+  if (Constant *C = getWithOperands(NewOps, getType(), true))
+    return C;
+
+  // Update to the new value.
+  return getContext().pImpl->ExprConstants.replaceOperandsInPlace(
+      NewOps, this, From, To, NumUpdated, OperandNo);
+}
+
+Instruction *ConstantExpr::getAsInstruction() const {
+  SmallVector<Value *, 4> ValueOperands(operands());
+  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:
+  case Instruction::AddrSpaceCast:
+    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], getShuffleMask());
+
+  case Instruction::GetElementPtr: {
+    const auto *GO = cast<GEPOperator>(this);
+    if (GO->isInBounds())
+      return GetElementPtrInst::CreateInBounds(GO->getSourceElementType(),
+                                               Ops[0], Ops.slice(1));
+    return GetElementPtrInst::Create(GO->getSourceElementType(), Ops[0],
+                                     Ops.slice(1));
+  }
+  case Instruction::ICmp:
+  case Instruction::FCmp:
+    return CmpInst::Create((Instruction::OtherOps)getOpcode(),
+                           (CmpInst::Predicate)getPredicate(), Ops[0], Ops[1]);
+  case Instruction::FNeg:
+    return UnaryOperator::Create((Instruction::UnaryOps)getOpcode(), Ops[0]);
+  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;
+  }
+}