Remove LLVM 8.0.1 files.

1 files changed, 0 insertions, 2373 deletions

diff --git a/gnu/llvm/lib/IR/ConstantFold.cpp b/gnu/llvm/lib/IR/ConstantFold.cpp
deleted file mode 100644
index 57de6b04230..00000000000
--- a/gnu/llvm/lib/IR/ConstantFold.cpp
+++ /dev/null
@@ -1,2373 +0,0 @@
-//===- ConstantFold.cpp - LLVM constant folder ----------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements folding of constants for LLVM.  This implements the
-// (internal) ConstantFold.h interface, which is used by the
-// ConstantExpr::get* methods to automatically fold constants when possible.
-//
-// The current constant folding implementation is implemented in two pieces: the
-// pieces that don't need DataLayout, and the pieces that do. This is to avoid
-// a dependence in IR on Target.
-//
-//===----------------------------------------------------------------------===//
-
-#include "ConstantFold.h"
-#include "llvm/ADT/APSInt.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/GetElementPtrTypeIterator.h"
-#include "llvm/IR/GlobalAlias.h"
-#include "llvm/IR/GlobalVariable.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/Operator.h"
-#include "llvm/IR/PatternMatch.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/ManagedStatic.h"
-#include "llvm/Support/MathExtras.h"
-using namespace llvm;
-using namespace llvm::PatternMatch;
-
-//===----------------------------------------------------------------------===//
-//                ConstantFold*Instruction Implementations
-//===----------------------------------------------------------------------===//
-
-/// Convert the specified vector Constant node to the specified vector type.
-/// At this point, we know that the elements of the input vector constant are
-/// all simple integer or FP values.
-static Constant *BitCastConstantVector(Constant *CV, VectorType *DstTy) {
-
-  if (CV->isAllOnesValue()) return Constant::getAllOnesValue(DstTy);
-  if (CV->isNullValue()) return Constant::getNullValue(DstTy);
-
-  // If this cast changes element count then we can't handle it here:
-  // doing so requires endianness information.  This should be handled by
-  // Analysis/ConstantFolding.cpp
-  unsigned NumElts = DstTy->getNumElements();
-  if (NumElts != CV->getType()->getVectorNumElements())
-    return nullptr;
-
-  Type *DstEltTy = DstTy->getElementType();
-
-  SmallVector<Constant*, 16> Result;
-  Type *Ty = IntegerType::get(CV->getContext(), 32);
-  for (unsigned i = 0; i != NumElts; ++i) {
-    Constant *C =
-      ConstantExpr::getExtractElement(CV, ConstantInt::get(Ty, i));
-    C = ConstantExpr::getBitCast(C, DstEltTy);
-    Result.push_back(C);
-  }
-
-  return ConstantVector::get(Result);
-}
-
-/// This function determines which opcode to use to fold two constant cast
-/// expressions together. It uses CastInst::isEliminableCastPair to determine
-/// the opcode. Consequently its just a wrapper around that function.
-/// Determine if it is valid to fold a cast of a cast
-static unsigned
-foldConstantCastPair(
-  unsigned opc,          ///< opcode of the second cast constant expression
-  ConstantExpr *Op,      ///< the first cast constant expression
-  Type *DstTy            ///< destination type of the first cast
-) {
-  assert(Op && Op->isCast() && "Can't fold cast of cast without a cast!");
-  assert(DstTy && DstTy->isFirstClassType() && "Invalid cast destination type");
-  assert(CastInst::isCast(opc) && "Invalid cast opcode");
-
-  // The types and opcodes for the two Cast constant expressions
-  Type *SrcTy = Op->getOperand(0)->getType();
-  Type *MidTy = Op->getType();
-  Instruction::CastOps firstOp = Instruction::CastOps(Op->getOpcode());
-  Instruction::CastOps secondOp = Instruction::CastOps(opc);
-
-  // Assume that pointers are never more than 64 bits wide, and only use this
-  // for the middle type. Otherwise we could end up folding away illegal
-  // bitcasts between address spaces with different sizes.
-  IntegerType *FakeIntPtrTy = Type::getInt64Ty(DstTy->getContext());
-
-  // Let CastInst::isEliminableCastPair do the heavy lifting.
-  return CastInst::isEliminableCastPair(firstOp, secondOp, SrcTy, MidTy, DstTy,
-                                        nullptr, FakeIntPtrTy, nullptr);
-}
-
-static Constant *FoldBitCast(Constant *V, Type *DestTy) {
-  Type *SrcTy = V->getType();
-  if (SrcTy == DestTy)
-    return V; // no-op cast
-
-  // Check to see if we are casting a pointer to an aggregate to a pointer to
-  // the first element.  If so, return the appropriate GEP instruction.
-  if (PointerType *PTy = dyn_cast<PointerType>(V->getType()))
-    if (PointerType *DPTy = dyn_cast<PointerType>(DestTy))
-      if (PTy->getAddressSpace() == DPTy->getAddressSpace()
-          && PTy->getElementType()->isSized()) {
-        SmallVector<Value*, 8> IdxList;
-        Value *Zero =
-          Constant::getNullValue(Type::getInt32Ty(DPTy->getContext()));
-        IdxList.push_back(Zero);
-        Type *ElTy = PTy->getElementType();
-        while (ElTy != DPTy->getElementType()) {
-          if (StructType *STy = dyn_cast<StructType>(ElTy)) {
-            if (STy->getNumElements() == 0) break;
-            ElTy = STy->getElementType(0);
-            IdxList.push_back(Zero);
-          } else if (SequentialType *STy =
-                     dyn_cast<SequentialType>(ElTy)) {
-            ElTy = STy->getElementType();
-            IdxList.push_back(Zero);
-          } else {
-            break;
-          }
-        }
-
-        if (ElTy == DPTy->getElementType())
-          // This GEP is inbounds because all indices are zero.
-          return ConstantExpr::getInBoundsGetElementPtr(PTy->getElementType(),
-                                                        V, IdxList);
-      }
-
-  // Handle casts from one vector constant to another.  We know that the src
-  // and dest type have the same size (otherwise its an illegal cast).
-  if (VectorType *DestPTy = dyn_cast<VectorType>(DestTy)) {
-    if (VectorType *SrcTy = dyn_cast<VectorType>(V->getType())) {
-      assert(DestPTy->getBitWidth() == SrcTy->getBitWidth() &&
-             "Not cast between same sized vectors!");
-      SrcTy = nullptr;
-      // First, check for null.  Undef is already handled.
-      if (isa<ConstantAggregateZero>(V))
-        return Constant::getNullValue(DestTy);
-
-      // Handle ConstantVector and ConstantAggregateVector.
-      return BitCastConstantVector(V, DestPTy);
-    }
-
-    // Canonicalize scalar-to-vector bitcasts into vector-to-vector bitcasts
-    // This allows for other simplifications (although some of them
-    // can only be handled by Analysis/ConstantFolding.cpp).
-    if (isa<ConstantInt>(V) || isa<ConstantFP>(V))
-      return ConstantExpr::getBitCast(ConstantVector::get(V), DestPTy);
-  }
-
-  // Finally, implement bitcast folding now.   The code below doesn't handle
-  // bitcast right.
-  if (isa<ConstantPointerNull>(V))  // ptr->ptr cast.
-    return ConstantPointerNull::get(cast<PointerType>(DestTy));
-
-  // Handle integral constant input.
-  if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
-    if (DestTy->isIntegerTy())
-      // Integral -> Integral. This is a no-op because the bit widths must
-      // be the same. Consequently, we just fold to V.
-      return V;
-
-    // See note below regarding the PPC_FP128 restriction.
-    if (DestTy->isFloatingPointTy() && !DestTy->isPPC_FP128Ty())
-      return ConstantFP::get(DestTy->getContext(),
-                             APFloat(DestTy->getFltSemantics(),
-                                     CI->getValue()));
-
-    // Otherwise, can't fold this (vector?)
-    return nullptr;
-  }
-
-  // Handle ConstantFP input: FP -> Integral.
-  if (ConstantFP *FP = dyn_cast<ConstantFP>(V)) {
-    // PPC_FP128 is really the sum of two consecutive doubles, where the first
-    // double is always stored first in memory, regardless of the target
-    // endianness. The memory layout of i128, however, depends on the target
-    // endianness, and so we can't fold this without target endianness
-    // information. This should instead be handled by
-    // Analysis/ConstantFolding.cpp
-    if (FP->getType()->isPPC_FP128Ty())
-      return nullptr;
-
-    // Make sure dest type is compatible with the folded integer constant.
-    if (!DestTy->isIntegerTy())
-      return nullptr;
-
-    return ConstantInt::get(FP->getContext(),
-                            FP->getValueAPF().bitcastToAPInt());
-  }
-
-  return nullptr;
-}
-
-
-/// V is an integer constant which only has a subset of its bytes used.
-/// The bytes used are indicated by ByteStart (which is the first byte used,
-/// counting from the least significant byte) and ByteSize, which is the number
-/// of bytes used.
-///
-/// This function analyzes the specified constant to see if the specified byte
-/// range can be returned as a simplified constant.  If so, the constant is
-/// returned, otherwise null is returned.
-static Constant *ExtractConstantBytes(Constant *C, unsigned ByteStart,
-                                      unsigned ByteSize) {
-  assert(C->getType()->isIntegerTy() &&
-         (cast<IntegerType>(C->getType())->getBitWidth() & 7) == 0 &&
-         "Non-byte sized integer input");
-  unsigned CSize = cast<IntegerType>(C->getType())->getBitWidth()/8;
-  assert(ByteSize && "Must be accessing some piece");
-  assert(ByteStart+ByteSize <= CSize && "Extracting invalid piece from input");
-  assert(ByteSize != CSize && "Should not extract everything");
-
-  // Constant Integers are simple.
-  if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
-    APInt V = CI->getValue();
-    if (ByteStart)
-      V.lshrInPlace(ByteStart*8);
-    V = V.trunc(ByteSize*8);
-    return ConstantInt::get(CI->getContext(), V);
-  }
-
-  // In the input is a constant expr, we might be able to recursively simplify.
-  // If not, we definitely can't do anything.
-  ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
-  if (!CE) return nullptr;
-
-  switch (CE->getOpcode()) {
-  default: return nullptr;
-  case Instruction::Or: {
-    Constant *RHS = ExtractConstantBytes(CE->getOperand(1), ByteStart,ByteSize);
-    if (!RHS)
-      return nullptr;
-
-    // X | -1 -> -1.
-    if (ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS))
-      if (RHSC->isMinusOne())
-        return RHSC;
-
-    Constant *LHS = ExtractConstantBytes(CE->getOperand(0), ByteStart,ByteSize);
-    if (!LHS)
-      return nullptr;
-    return ConstantExpr::getOr(LHS, RHS);
-  }
-  case Instruction::And: {
-    Constant *RHS = ExtractConstantBytes(CE->getOperand(1), ByteStart,ByteSize);
-    if (!RHS)
-      return nullptr;
-
-    // X & 0 -> 0.
-    if (RHS->isNullValue())
-      return RHS;
-
-    Constant *LHS = ExtractConstantBytes(CE->getOperand(0), ByteStart,ByteSize);
-    if (!LHS)
-      return nullptr;
-    return ConstantExpr::getAnd(LHS, RHS);
-  }
-  case Instruction::LShr: {
-    ConstantInt *Amt = dyn_cast<ConstantInt>(CE->getOperand(1));
-    if (!Amt)
-      return nullptr;
-    unsigned ShAmt = Amt->getZExtValue();
-    // Cannot analyze non-byte shifts.
-    if ((ShAmt & 7) != 0)
-      return nullptr;
-    ShAmt >>= 3;
-
-    // If the extract is known to be all zeros, return zero.
-    if (ByteStart >= CSize-ShAmt)
-      return Constant::getNullValue(IntegerType::get(CE->getContext(),
-                                                     ByteSize*8));
-    // If the extract is known to be fully in the input, extract it.
-    if (ByteStart+ByteSize+ShAmt <= CSize)
-      return ExtractConstantBytes(CE->getOperand(0), ByteStart+ShAmt, ByteSize);
-
-    // TODO: Handle the 'partially zero' case.
-    return nullptr;
-  }
-
-  case Instruction::Shl: {
-    ConstantInt *Amt = dyn_cast<ConstantInt>(CE->getOperand(1));
-    if (!Amt)
-      return nullptr;
-    unsigned ShAmt = Amt->getZExtValue();
-    // Cannot analyze non-byte shifts.
-    if ((ShAmt & 7) != 0)
-      return nullptr;
-    ShAmt >>= 3;
-
-    // If the extract is known to be all zeros, return zero.
-    if (ByteStart+ByteSize <= ShAmt)
-      return Constant::getNullValue(IntegerType::get(CE->getContext(),
-                                                     ByteSize*8));
-    // If the extract is known to be fully in the input, extract it.
-    if (ByteStart >= ShAmt)
-      return ExtractConstantBytes(CE->getOperand(0), ByteStart-ShAmt, ByteSize);
-
-    // TODO: Handle the 'partially zero' case.
-    return nullptr;
-  }
-
-  case Instruction::ZExt: {
-    unsigned SrcBitSize =
-      cast<IntegerType>(CE->getOperand(0)->getType())->getBitWidth();
-
-    // If extracting something that is completely zero, return 0.
-    if (ByteStart*8 >= SrcBitSize)
-      return Constant::getNullValue(IntegerType::get(CE->getContext(),
-                                                     ByteSize*8));
-
-    // If exactly extracting the input, return it.
-    if (ByteStart == 0 && ByteSize*8 == SrcBitSize)
-      return CE->getOperand(0);
-
-    // If extracting something completely in the input, if the input is a
-    // multiple of 8 bits, recurse.
-    if ((SrcBitSize&7) == 0 && (ByteStart+ByteSize)*8 <= SrcBitSize)
-      return ExtractConstantBytes(CE->getOperand(0), ByteStart, ByteSize);
-
-    // Otherwise, if extracting a subset of the input, which is not multiple of
-    // 8 bits, do a shift and trunc to get the bits.
-    if ((ByteStart+ByteSize)*8 < SrcBitSize) {
-      assert((SrcBitSize&7) && "Shouldn't get byte sized case here");
-      Constant *Res = CE->getOperand(0);
-      if (ByteStart)
-        Res = ConstantExpr::getLShr(Res,
-                                 ConstantInt::get(Res->getType(), ByteStart*8));
-      return ConstantExpr::getTrunc(Res, IntegerType::get(C->getContext(),
-                                                          ByteSize*8));
-    }
-
-    // TODO: Handle the 'partially zero' case.
-    return nullptr;
-  }
-  }
-}
-
-/// Return a ConstantExpr with type DestTy for sizeof on Ty, with any known
-/// factors factored out. If Folded is false, return null if no factoring was
-/// possible, to avoid endlessly bouncing an unfoldable expression back into the
-/// top-level folder.
-static Constant *getFoldedSizeOf(Type *Ty, Type *DestTy, bool Folded) {
-  if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
-    Constant *N = ConstantInt::get(DestTy, ATy->getNumElements());
-    Constant *E = getFoldedSizeOf(ATy->getElementType(), DestTy, true);
-    return ConstantExpr::getNUWMul(E, N);
-  }
-
-  if (StructType *STy = dyn_cast<StructType>(Ty))
-    if (!STy->isPacked()) {
-      unsigned NumElems = STy->getNumElements();
-      // An empty struct has size zero.
-      if (NumElems == 0)
-        return ConstantExpr::getNullValue(DestTy);
-      // Check for a struct with all members having the same size.
-      Constant *MemberSize =
-        getFoldedSizeOf(STy->getElementType(0), DestTy, true);
-      bool AllSame = true;
-      for (unsigned i = 1; i != NumElems; ++i)
-        if (MemberSize !=
-            getFoldedSizeOf(STy->getElementType(i), DestTy, true)) {
-          AllSame = false;
-          break;
-        }
-      if (AllSame) {
-        Constant *N = ConstantInt::get(DestTy, NumElems);
-        return ConstantExpr::getNUWMul(MemberSize, N);
-      }
-    }
-
-  // Pointer size doesn't depend on the pointee type, so canonicalize them
-  // to an arbitrary pointee.
-  if (PointerType *PTy = dyn_cast<PointerType>(Ty))
-    if (!PTy->getElementType()->isIntegerTy(1))
-      return
-        getFoldedSizeOf(PointerType::get(IntegerType::get(PTy->getContext(), 1),
-                                         PTy->getAddressSpace()),
-                        DestTy, true);
-
-  // If there's no interesting folding happening, bail so that we don't create
-  // a constant that looks like it needs folding but really doesn't.
-  if (!Folded)
-    return nullptr;
-
-  // Base case: Get a regular sizeof expression.
-  Constant *C = ConstantExpr::getSizeOf(Ty);
-  C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
-                                                    DestTy, false),
-                            C, DestTy);
-  return C;
-}
-
-/// Return a ConstantExpr with type DestTy for alignof on Ty, with any known
-/// factors factored out. If Folded is false, return null if no factoring was
-/// possible, to avoid endlessly bouncing an unfoldable expression back into the
-/// top-level folder.
-static Constant *getFoldedAlignOf(Type *Ty, Type *DestTy, bool Folded) {
-  // The alignment of an array is equal to the alignment of the
-  // array element. Note that this is not always true for vectors.
-  if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
-    Constant *C = ConstantExpr::getAlignOf(ATy->getElementType());
-    C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
-                                                      DestTy,
-                                                      false),
-                              C, DestTy);
-    return C;
-  }
-
-  if (StructType *STy = dyn_cast<StructType>(Ty)) {
-    // Packed structs always have an alignment of 1.
-    if (STy->isPacked())
-      return ConstantInt::get(DestTy, 1);
-
-    // Otherwise, struct alignment is the maximum alignment of any member.
-    // Without target data, we can't compare much, but we can check to see
-    // if all the members have the same alignment.
-    unsigned NumElems = STy->getNumElements();
-    // An empty struct has minimal alignment.
-    if (NumElems == 0)
-      return ConstantInt::get(DestTy, 1);
-    // Check for a struct with all members having the same alignment.
-    Constant *MemberAlign =
-      getFoldedAlignOf(STy->getElementType(0), DestTy, true);
-    bool AllSame = true;
-    for (unsigned i = 1; i != NumElems; ++i)
-      if (MemberAlign != getFoldedAlignOf(STy->getElementType(i), DestTy, true)) {
-        AllSame = false;
-        break;
-      }
-    if (AllSame)
-      return MemberAlign;
-  }
-
-  // Pointer alignment doesn't depend on the pointee type, so canonicalize them
-  // to an arbitrary pointee.
-  if (PointerType *PTy = dyn_cast<PointerType>(Ty))
-    if (!PTy->getElementType()->isIntegerTy(1))
-      return
-        getFoldedAlignOf(PointerType::get(IntegerType::get(PTy->getContext(),
-                                                           1),
-                                          PTy->getAddressSpace()),
-                         DestTy, true);
-
-  // If there's no interesting folding happening, bail so that we don't create
-  // a constant that looks like it needs folding but really doesn't.
-  if (!Folded)
-    return nullptr;
-
-  // Base case: Get a regular alignof expression.
-  Constant *C = ConstantExpr::getAlignOf(Ty);
-  C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
-                                                    DestTy, false),
-                            C, DestTy);
-  return C;
-}
-
-/// Return a ConstantExpr with type DestTy for offsetof on Ty and FieldNo, with
-/// any known factors factored out. If Folded is false, return null if no
-/// factoring was possible, to avoid endlessly bouncing an unfoldable expression
-/// back into the top-level folder.
-static Constant *getFoldedOffsetOf(Type *Ty, Constant *FieldNo, Type *DestTy,
-                                   bool Folded) {
-  if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
-    Constant *N = ConstantExpr::getCast(CastInst::getCastOpcode(FieldNo, false,
-                                                                DestTy, false),
-                                        FieldNo, DestTy);
-    Constant *E = getFoldedSizeOf(ATy->getElementType(), DestTy, true);
-    return ConstantExpr::getNUWMul(E, N);
-  }
-
-  if (StructType *STy = dyn_cast<StructType>(Ty))
-    if (!STy->isPacked()) {
-      unsigned NumElems = STy->getNumElements();
-      // An empty struct has no members.
-      if (NumElems == 0)
-        return nullptr;
-      // Check for a struct with all members having the same size.
-      Constant *MemberSize =
-        getFoldedSizeOf(STy->getElementType(0), DestTy, true);
-      bool AllSame = true;
-      for (unsigned i = 1; i != NumElems; ++i)
-        if (MemberSize !=
-            getFoldedSizeOf(STy->getElementType(i), DestTy, true)) {
-          AllSame = false;
-          break;
-        }
-      if (AllSame) {
-        Constant *N = ConstantExpr::getCast(CastInst::getCastOpcode(FieldNo,
-                                                                    false,
-                                                                    DestTy,
-                                                                    false),
-                                            FieldNo, DestTy);
-        return ConstantExpr::getNUWMul(MemberSize, N);
-      }
-    }
-
-  // If there's no interesting folding happening, bail so that we don't create
-  // a constant that looks like it needs folding but really doesn't.
-  if (!Folded)
-    return nullptr;
-
-  // Base case: Get a regular offsetof expression.
-  Constant *C = ConstantExpr::getOffsetOf(Ty, FieldNo);
-  C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
-                                                    DestTy, false),
-                            C, DestTy);
-  return C;
-}
-
-Constant *llvm::ConstantFoldCastInstruction(unsigned opc, Constant *V,
-                                            Type *DestTy) {
-  if (isa<UndefValue>(V)) {
-    // zext(undef) = 0, because the top bits will be zero.
-    // sext(undef) = 0, because the top bits will all be the same.
-    // [us]itofp(undef) = 0, because the result value is bounded.
-    if (opc == Instruction::ZExt || opc == Instruction::SExt ||
-        opc == Instruction::UIToFP || opc == Instruction::SIToFP)
-      return Constant::getNullValue(DestTy);
-    return UndefValue::get(DestTy);
-  }
-
-  if (V->isNullValue() && !DestTy->isX86_MMXTy() &&
-      opc != Instruction::AddrSpaceCast)
-    return Constant::getNullValue(DestTy);
-
-  // If the cast operand is a constant expression, there's a few things we can
-  // do to try to simplify it.
-  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
-    if (CE->isCast()) {
-      // Try hard to fold cast of cast because they are often eliminable.
-      if (unsigned newOpc = foldConstantCastPair(opc, CE, DestTy))
-        return ConstantExpr::getCast(newOpc, CE->getOperand(0), DestTy);
-    } else if (CE->getOpcode() == Instruction::GetElementPtr &&
-               // Do not fold addrspacecast (gep 0, .., 0). It might make the
-               // addrspacecast uncanonicalized.
-               opc != Instruction::AddrSpaceCast &&
-               // Do not fold bitcast (gep) with inrange index, as this loses
-               // information.
-               !cast<GEPOperator>(CE)->getInRangeIndex().hasValue() &&
-               // Do not fold if the gep type is a vector, as bitcasting
-               // operand 0 of a vector gep will result in a bitcast between
-               // different sizes.
-               !CE->getType()->isVectorTy()) {
-      // If all of the indexes in the GEP are null values, there is no pointer
-      // adjustment going on.  We might as well cast the source pointer.
-      bool isAllNull = true;
-      for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i)
-        if (!CE->getOperand(i)->isNullValue()) {
-          isAllNull = false;
-          break;
-        }
-      if (isAllNull)
-        // This is casting one pointer type to another, always BitCast
-        return ConstantExpr::getPointerCast(CE->getOperand(0), DestTy);
-    }
-  }
-
-  // If the cast operand is a constant vector, perform the cast by
-  // operating on each element. In the cast of bitcasts, the element
-  // count may be mismatched; don't attempt to handle that here.
-  if ((isa<ConstantVector>(V) || isa<ConstantDataVector>(V)) &&
-      DestTy->isVectorTy() &&
-      DestTy->getVectorNumElements() == V->getType()->getVectorNumElements()) {
-    SmallVector<Constant*, 16> res;
-    VectorType *DestVecTy = cast<VectorType>(DestTy);
-    Type *DstEltTy = DestVecTy->getElementType();
-    Type *Ty = IntegerType::get(V->getContext(), 32);
-    for (unsigned i = 0, e = V->getType()->getVectorNumElements(); i != e; ++i) {
-      Constant *C =
-        ConstantExpr::getExtractElement(V, ConstantInt::get(Ty, i));
-      res.push_back(ConstantExpr::getCast(opc, C, DstEltTy));
-    }
-    return ConstantVector::get(res);
-  }
-
-  // We actually have to do a cast now. Perform the cast according to the
-  // opcode specified.
-  switch (opc) {
-  default:
-    llvm_unreachable("Failed to cast constant expression");
-  case Instruction::FPTrunc:
-  case Instruction::FPExt:
-    if (ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
-      bool ignored;
-      APFloat Val = FPC->getValueAPF();
-      Val.convert(DestTy->isHalfTy() ? APFloat::IEEEhalf() :
-                  DestTy->isFloatTy() ? APFloat::IEEEsingle() :
-                  DestTy->isDoubleTy() ? APFloat::IEEEdouble() :
-                  DestTy->isX86_FP80Ty() ? APFloat::x87DoubleExtended() :
-                  DestTy->isFP128Ty() ? APFloat::IEEEquad() :
-                  DestTy->isPPC_FP128Ty() ? APFloat::PPCDoubleDouble() :
-                  APFloat::Bogus(),
-                  APFloat::rmNearestTiesToEven, &ignored);
-      return ConstantFP::get(V->getContext(), Val);
-    }
-    return nullptr; // Can't fold.
-  case Instruction::FPToUI:
-  case Instruction::FPToSI:
-    if (ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
-      const APFloat &V = FPC->getValueAPF();
-      bool ignored;
-      uint32_t DestBitWidth = cast<IntegerType>(DestTy)->getBitWidth();
-      APSInt IntVal(DestBitWidth, opc == Instruction::FPToUI);
-      if (APFloat::opInvalidOp ==
-          V.convertToInteger(IntVal, APFloat::rmTowardZero, &ignored)) {
-        // Undefined behavior invoked - the destination type can't represent
-        // the input constant.
-        return UndefValue::get(DestTy);
-      }
-      return ConstantInt::get(FPC->getContext(), IntVal);
-    }
-    return nullptr; // Can't fold.
-  case Instruction::IntToPtr:   //always treated as unsigned
-    if (V->isNullValue())       // Is it an integral null value?
-      return ConstantPointerNull::get(cast<PointerType>(DestTy));
-    return nullptr;                   // Other pointer types cannot be casted
-  case Instruction::PtrToInt:   // always treated as unsigned
-    // Is it a null pointer value?
-    if (V->isNullValue())
-      return ConstantInt::get(DestTy, 0);
-    // If this is a sizeof-like expression, pull out multiplications by
-    // known factors to expose them to subsequent folding. If it's an
-    // alignof-like expression, factor out known factors.
-    if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
-      if (CE->getOpcode() == Instruction::GetElementPtr &&
-          CE->getOperand(0)->isNullValue()) {
-        // FIXME: Looks like getFoldedSizeOf(), getFoldedOffsetOf() and
-        // getFoldedAlignOf() don't handle the case when DestTy is a vector of
-        // pointers yet. We end up in asserts in CastInst::getCastOpcode (see
-        // test/Analysis/ConstantFolding/cast-vector.ll). I've only seen this
-        // happen in one "real" C-code test case, so it does not seem to be an
-        // important optimization to handle vectors here. For now, simply bail
-        // out.
-        if (DestTy->isVectorTy())
-          return nullptr;
-        GEPOperator *GEPO = cast<GEPOperator>(CE);
-        Type *Ty = GEPO->getSourceElementType();
-        if (CE->getNumOperands() == 2) {
-          // Handle a sizeof-like expression.
-          Constant *Idx = CE->getOperand(1);
-          bool isOne = isa<ConstantInt>(Idx) && cast<ConstantInt>(Idx)->isOne();
-          if (Constant *C = getFoldedSizeOf(Ty, DestTy, !isOne)) {
-            Idx = ConstantExpr::getCast(CastInst::getCastOpcode(Idx, true,
-                                                                DestTy, false),
-                                        Idx, DestTy);
-            return ConstantExpr::getMul(C, Idx);
-          }
-        } else if (CE->getNumOperands() == 3 &&
-                   CE->getOperand(1)->isNullValue()) {
-          // Handle an alignof-like expression.
-          if (StructType *STy = dyn_cast<StructType>(Ty))
-            if (!STy->isPacked()) {
-              ConstantInt *CI = cast<ConstantInt>(CE->getOperand(2));
-              if (CI->isOne() &&
-                  STy->getNumElements() == 2 &&
-                  STy->getElementType(0)->isIntegerTy(1)) {
-                return getFoldedAlignOf(STy->getElementType(1), DestTy, false);
-              }
-            }
-          // Handle an offsetof-like expression.
-          if (Ty->isStructTy() || Ty->isArrayTy()) {
-            if (Constant *C = getFoldedOffsetOf(Ty, CE->getOperand(2),
-                                                DestTy, false))
-              return C;
-          }
-        }
-      }
-    // Other pointer types cannot be casted
-    return nullptr;
-  case Instruction::UIToFP:
-  case Instruction::SIToFP:
-    if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
-      const APInt &api = CI->getValue();
-      APFloat apf(DestTy->getFltSemantics(),
-                  APInt::getNullValue(DestTy->getPrimitiveSizeInBits()));
-      apf.convertFromAPInt(api, opc==Instruction::SIToFP,
-                           APFloat::rmNearestTiesToEven);
-      return ConstantFP::get(V->getContext(), apf);
-    }
-    return nullptr;
-  case Instruction::ZExt:
-    if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
-      uint32_t BitWidth = cast<IntegerType>(DestTy)->getBitWidth();
-      return ConstantInt::get(V->getContext(),
-                              CI->getValue().zext(BitWidth));
-    }
-    return nullptr;
-  case Instruction::SExt:
-    if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
-      uint32_t BitWidth = cast<IntegerType>(DestTy)->getBitWidth();
-      return ConstantInt::get(V->getContext(),
-                              CI->getValue().sext(BitWidth));
-    }
-    return nullptr;
-  case Instruction::Trunc: {
-    if (V->getType()->isVectorTy())
-      return nullptr;
-
-    uint32_t DestBitWidth = cast<IntegerType>(DestTy)->getBitWidth();
-    if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
-      return ConstantInt::get(V->getContext(),
-                              CI->getValue().trunc(DestBitWidth));
-    }
-
-    // The input must be a constantexpr.  See if we can simplify this based on
-    // the bytes we are demanding.  Only do this if the source and dest are an
-    // even multiple of a byte.
-    if ((DestBitWidth & 7) == 0 &&
-        (cast<IntegerType>(V->getType())->getBitWidth() & 7) == 0)
-      if (Constant *Res = ExtractConstantBytes(V, 0, DestBitWidth / 8))
-        return Res;
-
-    return nullptr;
-  }
-  case Instruction::BitCast:
-    return FoldBitCast(V, DestTy);
-  case Instruction::AddrSpaceCast:
-    return nullptr;
-  }
-}
-
-Constant *llvm::ConstantFoldSelectInstruction(Constant *Cond,
-                                              Constant *V1, Constant *V2) {
-  // Check for i1 and vector true/false conditions.
-  if (Cond->isNullValue()) return V2;
-  if (Cond->isAllOnesValue()) return V1;
-
-  // If the condition is a vector constant, fold the result elementwise.
-  if (ConstantVector *CondV = dyn_cast<ConstantVector>(Cond)) {
-    SmallVector<Constant*, 16> Result;
-    Type *Ty = IntegerType::get(CondV->getContext(), 32);
-    for (unsigned i = 0, e = V1->getType()->getVectorNumElements(); i != e;++i){
-      Constant *V;
-      Constant *V1Element = ConstantExpr::getExtractElement(V1,
-                                                    ConstantInt::get(Ty, i));
-      Constant *V2Element = ConstantExpr::getExtractElement(V2,
-                                                    ConstantInt::get(Ty, i));
-      Constant *Cond = dyn_cast<Constant>(CondV->getOperand(i));
-      if (V1Element == V2Element) {
-        V = V1Element;
-      } else if (isa<UndefValue>(Cond)) {
-        V = isa<UndefValue>(V1Element) ? V1Element : V2Element;
-      } else {
-        if (!isa<ConstantInt>(Cond)) break;
-        V = Cond->isNullValue() ? V2Element : V1Element;
-      }
-      Result.push_back(V);
-    }
-
-    // If we were able to build the vector, return it.
-    if (Result.size() == V1->getType()->getVectorNumElements())
-      return ConstantVector::get(Result);
-  }
-
-  if (isa<UndefValue>(Cond)) {
-    if (isa<UndefValue>(V1)) return V1;
-    return V2;
-  }
-  if (isa<UndefValue>(V1)) return V2;
-  if (isa<UndefValue>(V2)) return V1;
-  if (V1 == V2) return V1;
-
-  if (ConstantExpr *TrueVal = dyn_cast<ConstantExpr>(V1)) {
-    if (TrueVal->getOpcode() == Instruction::Select)
-      if (TrueVal->getOperand(0) == Cond)
-        return ConstantExpr::getSelect(Cond, TrueVal->getOperand(1), V2);
-  }
-  if (ConstantExpr *FalseVal = dyn_cast<ConstantExpr>(V2)) {
-    if (FalseVal->getOpcode() == Instruction::Select)
-      if (FalseVal->getOperand(0) == Cond)
-        return ConstantExpr::getSelect(Cond, V1, FalseVal->getOperand(2));
-  }
-
-  return nullptr;
-}
-
-Constant *llvm::ConstantFoldExtractElementInstruction(Constant *Val,
-                                                      Constant *Idx) {
-  if (isa<UndefValue>(Val))  // ee(undef, x) -> undef
-    return UndefValue::get(Val->getType()->getVectorElementType());
-  if (Val->isNullValue())  // ee(zero, x) -> zero
-    return Constant::getNullValue(Val->getType()->getVectorElementType());
-  // ee({w,x,y,z}, undef) -> undef
-  if (isa<UndefValue>(Idx))
-    return UndefValue::get(Val->getType()->getVectorElementType());
-
-  if (ConstantInt *CIdx = dyn_cast<ConstantInt>(Idx)) {
-    // ee({w,x,y,z}, wrong_value) -> undef
-    if (CIdx->uge(Val->getType()->getVectorNumElements()))
-      return UndefValue::get(Val->getType()->getVectorElementType());
-    return Val->getAggregateElement(CIdx->getZExtValue());
-  }
-  return nullptr;
-}
-
-Constant *llvm::ConstantFoldInsertElementInstruction(Constant *Val,
-                                                     Constant *Elt,
-                                                     Constant *Idx) {
-  if (isa<UndefValue>(Idx))
-    return UndefValue::get(Val->getType());
-
-  ConstantInt *CIdx = dyn_cast<ConstantInt>(Idx);
-  if (!CIdx) return nullptr;
-
-  unsigned NumElts = Val->getType()->getVectorNumElements();
-  if (CIdx->uge(NumElts))
-    return UndefValue::get(Val->getType());
-
-  SmallVector<Constant*, 16> Result;
-  Result.reserve(NumElts);
-  auto *Ty = Type::getInt32Ty(Val->getContext());
-  uint64_t IdxVal = CIdx->getZExtValue();
-  for (unsigned i = 0; i != NumElts; ++i) {
-    if (i == IdxVal) {
-      Result.push_back(Elt);
-      continue;
-    }
-
-    Constant *C = ConstantExpr::getExtractElement(Val, ConstantInt::get(Ty, i));
-    Result.push_back(C);
-  }
-
-  return ConstantVector::get(Result);
-}
-
-Constant *llvm::ConstantFoldShuffleVectorInstruction(Constant *V1,
-                                                     Constant *V2,
-                                                     Constant *Mask) {
-  unsigned MaskNumElts = Mask->getType()->getVectorNumElements();
-  Type *EltTy = V1->getType()->getVectorElementType();
-
-  // Undefined shuffle mask -> undefined value.
-  if (isa<UndefValue>(Mask))
-    return UndefValue::get(VectorType::get(EltTy, MaskNumElts));
-
-  // Don't break the bitcode reader hack.
-  if (isa<ConstantExpr>(Mask)) return nullptr;
-
-  unsigned SrcNumElts = V1->getType()->getVectorNumElements();
-
-  // Loop over the shuffle mask, evaluating each element.
-  SmallVector<Constant*, 32> Result;
-  for (unsigned i = 0; i != MaskNumElts; ++i) {
-    int Elt = ShuffleVectorInst::getMaskValue(Mask, i);
-    if (Elt == -1) {
-      Result.push_back(UndefValue::get(EltTy));
-      continue;
-    }
-    Constant *InElt;
-    if (unsigned(Elt) >= SrcNumElts*2)
-      InElt = UndefValue::get(EltTy);
-    else if (unsigned(Elt) >= SrcNumElts) {
-      Type *Ty = IntegerType::get(V2->getContext(), 32);
-      InElt =
-        ConstantExpr::getExtractElement(V2,
-                                        ConstantInt::get(Ty, Elt - SrcNumElts));
-    } else {
-      Type *Ty = IntegerType::get(V1->getContext(), 32);
-      InElt = ConstantExpr::getExtractElement(V1, ConstantInt::get(Ty, Elt));
-    }
-    Result.push_back(InElt);
-  }
-
-  return ConstantVector::get(Result);
-}
-
-Constant *llvm::ConstantFoldExtractValueInstruction(Constant *Agg,
-                                                    ArrayRef<unsigned> Idxs) {
-  // Base case: no indices, so return the entire value.
-  if (Idxs.empty())
-    return Agg;
-
-  if (Constant *C = Agg->getAggregateElement(Idxs[0]))
-    return ConstantFoldExtractValueInstruction(C, Idxs.slice(1));
-
-  return nullptr;
-}
-
-Constant *llvm::ConstantFoldInsertValueInstruction(Constant *Agg,
-                                                   Constant *Val,
-                                                   ArrayRef<unsigned> Idxs) {
-  // Base case: no indices, so replace the entire value.
-  if (Idxs.empty())
-    return Val;
-
-  unsigned NumElts;
-  if (StructType *ST = dyn_cast<StructType>(Agg->getType()))
-    NumElts = ST->getNumElements();
-  else
-    NumElts = cast<SequentialType>(Agg->getType())->getNumElements();
-
-  SmallVector<Constant*, 32> Result;
-  for (unsigned i = 0; i != NumElts; ++i) {
-    Constant *C = Agg->getAggregateElement(i);
-    if (!C) return nullptr;
-
-    if (Idxs[0] == i)
-      C = ConstantFoldInsertValueInstruction(C, Val, Idxs.slice(1));
-
-    Result.push_back(C);
-  }
-
-  if (StructType *ST = dyn_cast<StructType>(Agg->getType()))
-    return ConstantStruct::get(ST, Result);
-  if (ArrayType *AT = dyn_cast<ArrayType>(Agg->getType()))
-    return ConstantArray::get(AT, Result);
-  return ConstantVector::get(Result);
-}
-
-Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode, Constant *C1,
-                                              Constant *C2) {
-  assert(Instruction::isBinaryOp(Opcode) && "Non-binary instruction detected");
-
-  // Handle scalar UndefValue. Vectors are always evaluated per element.
-  bool HasScalarUndef = !C1->getType()->isVectorTy() &&
-                        (isa<UndefValue>(C1) || isa<UndefValue>(C2));
-  if (HasScalarUndef) {
-    switch (static_cast<Instruction::BinaryOps>(Opcode)) {
-    case Instruction::Xor:
-      if (isa<UndefValue>(C1) && isa<UndefValue>(C2))
-        // Handle undef ^ undef -> 0 special case. This is a common
-        // idiom (misuse).
-        return Constant::getNullValue(C1->getType());
-      LLVM_FALLTHROUGH;
-    case Instruction::Add:
-    case Instruction::Sub:
-      return UndefValue::get(C1->getType());
-    case Instruction::And:
-      if (isa<UndefValue>(C1) && isa<UndefValue>(C2)) // undef & undef -> undef
-        return C1;
-      return Constant::getNullValue(C1->getType());   // undef & X -> 0
-    case Instruction::Mul: {
-      // undef * undef -> undef
-      if (isa<UndefValue>(C1) && isa<UndefValue>(C2))
-        return C1;
-      const APInt *CV;
-      // X * undef -> undef   if X is odd
-      if (match(C1, m_APInt(CV)) || match(C2, m_APInt(CV)))
-        if ((*CV)[0])
-          return UndefValue::get(C1->getType());
-
-      // X * undef -> 0       otherwise
-      return Constant::getNullValue(C1->getType());
-    }
-    case Instruction::SDiv:
-    case Instruction::UDiv:
-      // X / undef -> undef
-      if (isa<UndefValue>(C2))
-        return C2;
-      // undef / 0 -> undef
-      // undef / 1 -> undef
-      if (match(C2, m_Zero()) || match(C2, m_One()))
-        return C1;
-      // undef / X -> 0       otherwise
-      return Constant::getNullValue(C1->getType());
-    case Instruction::URem:
-    case Instruction::SRem:
-      // X % undef -> undef
-      if (match(C2, m_Undef()))
-        return C2;
-      // undef % 0 -> undef
-      if (match(C2, m_Zero()))
-        return C1;
-      // undef % X -> 0       otherwise
-      return Constant::getNullValue(C1->getType());
-    case Instruction::Or:                          // X | undef -> -1
-      if (isa<UndefValue>(C1) && isa<UndefValue>(C2)) // undef | undef -> undef
-        return C1;
-      return Constant::getAllOnesValue(C1->getType()); // undef | X -> ~0
-    case Instruction::LShr:
-      // X >>l undef -> undef
-      if (isa<UndefValue>(C2))
-        return C2;
-      // undef >>l 0 -> undef
-      if (match(C2, m_Zero()))
-        return C1;
-      // undef >>l X -> 0
-      return Constant::getNullValue(C1->getType());
-    case Instruction::AShr:
-      // X >>a undef -> undef
-      if (isa<UndefValue>(C2))
-        return C2;
-      // undef >>a 0 -> undef
-      if (match(C2, m_Zero()))
-        return C1;
-      // TODO: undef >>a X -> undef if the shift is exact
-      // undef >>a X -> 0
-      return Constant::getNullValue(C1->getType());
-    case Instruction::Shl:
-      // X << undef -> undef
-      if (isa<UndefValue>(C2))
-        return C2;
-      // undef << 0 -> undef
-      if (match(C2, m_Zero()))
-        return C1;
-      // undef << X -> 0
-      return Constant::getNullValue(C1->getType());
-    case Instruction::FAdd:
-    case Instruction::FSub:
-    case Instruction::FMul:
-    case Instruction::FDiv:
-    case Instruction::FRem:
-      // [any flop] undef, undef -> undef
-      if (isa<UndefValue>(C1) && isa<UndefValue>(C2))
-        return C1;
-      // [any flop] C, undef -> NaN
-      // [any flop] undef, C -> NaN
-      // We could potentially specialize NaN/Inf constants vs. 'normal'
-      // constants (possibly differently depending on opcode and operand). This
-      // would allow returning undef sometimes. But it is always safe to fold to
-      // NaN because we can choose the undef operand as NaN, and any FP opcode
-      // with a NaN operand will propagate NaN.
-      return ConstantFP::getNaN(C1->getType());
-    case Instruction::BinaryOpsEnd:
-      llvm_unreachable("Invalid BinaryOp");
-    }
-  }
-
-  // Neither constant should be UndefValue, unless these are vector constants.
-  assert(!HasScalarUndef && "Unexpected UndefValue");
-
-  // Handle simplifications when the RHS is a constant int.
-  if (ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
-    switch (Opcode) {
-    case Instruction::Add:
-      if (CI2->isZero()) return C1;                             // X + 0 == X
-      break;
-    case Instruction::Sub:
-      if (CI2->isZero()) return C1;                             // X - 0 == X
-      break;
-    case Instruction::Mul:
-      if (CI2->isZero()) return C2;                             // X * 0 == 0
-      if (CI2->isOne())
-        return C1;                                              // X * 1 == X
-      break;
-    case Instruction::UDiv:
-    case Instruction::SDiv:
-      if (CI2->isOne())
-        return C1;                                            // X / 1 == X
-      if (CI2->isZero())
-        return UndefValue::get(CI2->getType());               // X / 0 == undef
-      break;
-    case Instruction::URem:
-    case Instruction::SRem:
-      if (CI2->isOne())
-        return Constant::getNullValue(CI2->getType());        // X % 1 == 0
-      if (CI2->isZero())
-        return UndefValue::get(CI2->getType());               // X % 0 == undef
-      break;
-    case Instruction::And:
-      if (CI2->isZero()) return C2;                           // X & 0 == 0
-      if (CI2->isMinusOne())
-        return C1;                                            // X & -1 == X
-
-      if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
-        // (zext i32 to i64) & 4294967295 -> (zext i32 to i64)
-        if (CE1->getOpcode() == Instruction::ZExt) {
-          unsigned DstWidth = CI2->getType()->getBitWidth();
-          unsigned SrcWidth =
-            CE1->getOperand(0)->getType()->getPrimitiveSizeInBits();
-          APInt PossiblySetBits(APInt::getLowBitsSet(DstWidth, SrcWidth));
-          if ((PossiblySetBits & CI2->getValue()) == PossiblySetBits)
-            return C1;
-        }
-
-        // If and'ing the address of a global with a constant, fold it.
-        if (CE1->getOpcode() == Instruction::PtrToInt &&
-            isa<GlobalValue>(CE1->getOperand(0))) {
-          GlobalValue *GV = cast<GlobalValue>(CE1->getOperand(0));
-
-          // Functions are at least 4-byte aligned.
-          unsigned GVAlign = GV->getAlignment();
-          if (isa<Function>(GV))
-            GVAlign = std::max(GVAlign, 4U);
-
-          if (GVAlign > 1) {
-            unsigned DstWidth = CI2->getType()->getBitWidth();
-            unsigned SrcWidth = std::min(DstWidth, Log2_32(GVAlign));
-            APInt BitsNotSet(APInt::getLowBitsSet(DstWidth, SrcWidth));
-
-            // If checking bits we know are clear, return zero.
-            if ((CI2->getValue() & BitsNotSet) == CI2->getValue())
-              return Constant::getNullValue(CI2->getType());
-          }
-        }
-      }
-      break;
-    case Instruction::Or:
-      if (CI2->isZero()) return C1;        // X | 0 == X
-      if (CI2->isMinusOne())
-        return C2;                         // X | -1 == -1
-      break;
-    case Instruction::Xor:
-      if (CI2->isZero()) return C1;        // X ^ 0 == X
-
-      if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
-        switch (CE1->getOpcode()) {
-        default: break;
-        case Instruction::ICmp:
-        case Instruction::FCmp:
-          // cmp pred ^ true -> cmp !pred
-          assert(CI2->isOne());
-          CmpInst::Predicate pred = (CmpInst::Predicate)CE1->getPredicate();
-          pred = CmpInst::getInversePredicate(pred);
-          return ConstantExpr::getCompare(pred, CE1->getOperand(0),
-                                          CE1->getOperand(1));
-        }
-      }
-      break;
-    case Instruction::AShr:
-      // ashr (zext C to Ty), C2 -> lshr (zext C, CSA), C2
-      if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1))
-        if (CE1->getOpcode() == Instruction::ZExt)  // Top bits known zero.
-          return ConstantExpr::getLShr(C1, C2);
-      break;
-    }
-  } else if (isa<ConstantInt>(C1)) {
-    // If C1 is a ConstantInt and C2 is not, swap the operands.
-    if (Instruction::isCommutative(Opcode))
-      return ConstantExpr::get(Opcode, C2, C1);
-  }
-
-  if (ConstantInt *CI1 = dyn_cast<ConstantInt>(C1)) {
-    if (ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
-      const APInt &C1V = CI1->getValue();
-      const APInt &C2V = CI2->getValue();
-      switch (Opcode) {
-      default:
-        break;
-      case Instruction::Add:
-        return ConstantInt::get(CI1->getContext(), C1V + C2V);
-      case Instruction::Sub:
-        return ConstantInt::get(CI1->getContext(), C1V - C2V);
-      case Instruction::Mul:
-        return ConstantInt::get(CI1->getContext(), C1V * C2V);
-      case Instruction::UDiv:
-        assert(!CI2->isZero() && "Div by zero handled above");
-        return ConstantInt::get(CI1->getContext(), C1V.udiv(C2V));
-      case Instruction::SDiv:
-        assert(!CI2->isZero() && "Div by zero handled above");
-        if (C2V.isAllOnesValue() && C1V.isMinSignedValue())
-          return UndefValue::get(CI1->getType());   // MIN_INT / -1 -> undef
-        return ConstantInt::get(CI1->getContext(), C1V.sdiv(C2V));
-      case Instruction::URem:
-        assert(!CI2->isZero() && "Div by zero handled above");
-        return ConstantInt::get(CI1->getContext(), C1V.urem(C2V));
-      case Instruction::SRem:
-        assert(!CI2->isZero() && "Div by zero handled above");
-        if (C2V.isAllOnesValue() && C1V.isMinSignedValue())
-          return UndefValue::get(CI1->getType());   // MIN_INT % -1 -> undef
-        return ConstantInt::get(CI1->getContext(), C1V.srem(C2V));
-      case Instruction::And:
-        return ConstantInt::get(CI1->getContext(), C1V & C2V);
-      case Instruction::Or:
-        return ConstantInt::get(CI1->getContext(), C1V | C2V);
-      case Instruction::Xor:
-        return ConstantInt::get(CI1->getContext(), C1V ^ C2V);
-      case Instruction::Shl:
-        if (C2V.ult(C1V.getBitWidth()))
-          return ConstantInt::get(CI1->getContext(), C1V.shl(C2V));
-        return UndefValue::get(C1->getType()); // too big shift is undef
-      case Instruction::LShr:
-        if (C2V.ult(C1V.getBitWidth()))
-          return ConstantInt::get(CI1->getContext(), C1V.lshr(C2V));
-        return UndefValue::get(C1->getType()); // too big shift is undef
-      case Instruction::AShr:
-        if (C2V.ult(C1V.getBitWidth()))
-          return ConstantInt::get(CI1->getContext(), C1V.ashr(C2V));
-        return UndefValue::get(C1->getType()); // too big shift is undef
-      }
-    }
-
-    switch (Opcode) {
-    case Instruction::SDiv:
-    case Instruction::UDiv:
-    case Instruction::URem:
-    case Instruction::SRem:
-    case Instruction::LShr:
-    case Instruction::AShr:
-    case Instruction::Shl:
-      if (CI1->isZero()) return C1;
-      break;
-    default:
-      break;
-    }
-  } else if (ConstantFP *CFP1 = dyn_cast<ConstantFP>(C1)) {
-    if (ConstantFP *CFP2 = dyn_cast<ConstantFP>(C2)) {
-      const APFloat &C1V = CFP1->getValueAPF();
-      const APFloat &C2V = CFP2->getValueAPF();
-      APFloat C3V = C1V;  // copy for modification
-      switch (Opcode) {
-      default:
-        break;
-      case Instruction::FAdd:
-        (void)C3V.add(C2V, APFloat::rmNearestTiesToEven);
-        return ConstantFP::get(C1->getContext(), C3V);
-      case Instruction::FSub:
-        (void)C3V.subtract(C2V, APFloat::rmNearestTiesToEven);
-        return ConstantFP::get(C1->getContext(), C3V);
-      case Instruction::FMul:
-        (void)C3V.multiply(C2V, APFloat::rmNearestTiesToEven);
-        return ConstantFP::get(C1->getContext(), C3V);
-      case Instruction::FDiv:
-        (void)C3V.divide(C2V, APFloat::rmNearestTiesToEven);
-        return ConstantFP::get(C1->getContext(), C3V);
-      case Instruction::FRem:
-        (void)C3V.mod(C2V);
-        return ConstantFP::get(C1->getContext(), C3V);
-      }
-    }
-  } else if (VectorType *VTy = dyn_cast<VectorType>(C1->getType())) {
-    // Fold each element and create a vector constant from those constants.
-    SmallVector<Constant*, 16> Result;
-    Type *Ty = IntegerType::get(VTy->getContext(), 32);
-    for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
-      Constant *ExtractIdx = ConstantInt::get(Ty, i);
-      Constant *LHS = ConstantExpr::getExtractElement(C1, ExtractIdx);
-      Constant *RHS = ConstantExpr::getExtractElement(C2, ExtractIdx);
-
-      // If any element of a divisor vector is zero, the whole op is undef.
-      if (Instruction::isIntDivRem(Opcode) && RHS->isNullValue())
-        return UndefValue::get(VTy);
-
-      Result.push_back(ConstantExpr::get(Opcode, LHS, RHS));
-    }
-
-    return ConstantVector::get(Result);
-  }
-
-  if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
-    // There are many possible foldings we could do here.  We should probably
-    // at least fold add of a pointer with an integer into the appropriate
-    // getelementptr.  This will improve alias analysis a bit.
-
-    // Given ((a + b) + c), if (b + c) folds to something interesting, return
-    // (a + (b + c)).
-    if (Instruction::isAssociative(Opcode) && CE1->getOpcode() == Opcode) {
-      Constant *T = ConstantExpr::get(Opcode, CE1->getOperand(1), C2);
-      if (!isa<ConstantExpr>(T) || cast<ConstantExpr>(T)->getOpcode() != Opcode)
-        return ConstantExpr::get(Opcode, CE1->getOperand(0), T);
-    }
-  } else if (isa<ConstantExpr>(C2)) {
-    // If C2 is a constant expr and C1 isn't, flop them around and fold the
-    // other way if possible.
-    if (Instruction::isCommutative(Opcode))
-      return ConstantFoldBinaryInstruction(Opcode, C2, C1);
-  }
-
-  // i1 can be simplified in many cases.
-  if (C1->getType()->isIntegerTy(1)) {
-    switch (Opcode) {
-    case Instruction::Add:
-    case Instruction::Sub:
-      return ConstantExpr::getXor(C1, C2);
-    case Instruction::Mul:
-      return ConstantExpr::getAnd(C1, C2);
-    case Instruction::Shl:
-    case Instruction::LShr:
-    case Instruction::AShr:
-      // We can assume that C2 == 0.  If it were one the result would be
-      // undefined because the shift value is as large as the bitwidth.
-      return C1;
-    case Instruction::SDiv:
-    case Instruction::UDiv:
-      // We can assume that C2 == 1.  If it were zero the result would be
-      // undefined through division by zero.
-      return C1;
-    case Instruction::URem:
-    case Instruction::SRem:
-      // We can assume that C2 == 1.  If it were zero the result would be
-      // undefined through division by zero.
-      return ConstantInt::getFalse(C1->getContext());
-    default:
-      break;
-    }
-  }
-
-  // We don't know how to fold this.
-  return nullptr;
-}
-
-/// This type is zero-sized if it's an array or structure of zero-sized types.
-/// The only leaf zero-sized type is an empty structure.
-static bool isMaybeZeroSizedType(Type *Ty) {
-  if (StructType *STy = dyn_cast<StructType>(Ty)) {
-    if (STy->isOpaque()) return true;  // Can't say.
-
-    // If all of elements have zero size, this does too.
-    for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i)
-      if (!isMaybeZeroSizedType(STy->getElementType(i))) return false;
-    return true;
-
-  } else if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
-    return isMaybeZeroSizedType(ATy->getElementType());
-  }
-  return false;
-}
-
-/// Compare the two constants as though they were getelementptr indices.
-/// This allows coercion of the types to be the same thing.
-///
-/// If the two constants are the "same" (after coercion), return 0.  If the
-/// first is less than the second, return -1, if the second is less than the
-/// first, return 1.  If the constants are not integral, return -2.
-///
-static int IdxCompare(Constant *C1, Constant *C2, Type *ElTy) {
-  if (C1 == C2) return 0;
-
-  // Ok, we found a different index.  If they are not ConstantInt, we can't do
-  // anything with them.
-  if (!isa<ConstantInt>(C1) || !isa<ConstantInt>(C2))
-    return -2; // don't know!
-
-  // We cannot compare the indices if they don't fit in an int64_t.
-  if (cast<ConstantInt>(C1)->getValue().getActiveBits() > 64 ||
-      cast<ConstantInt>(C2)->getValue().getActiveBits() > 64)
-    return -2; // don't know!
-
-  // Ok, we have two differing integer indices.  Sign extend them to be the same
-  // type.
-  int64_t C1Val = cast<ConstantInt>(C1)->getSExtValue();
-  int64_t C2Val = cast<ConstantInt>(C2)->getSExtValue();
-
-  if (C1Val == C2Val) return 0;  // They are equal
-
-  // If the type being indexed over is really just a zero sized type, there is
-  // no pointer difference being made here.
-  if (isMaybeZeroSizedType(ElTy))
-    return -2; // dunno.
-
-  // If they are really different, now that they are the same type, then we
-  // found a difference!
-  if (C1Val < C2Val)
-    return -1;
-  else
-    return 1;
-}
-
-/// This function determines if there is anything we can decide about the two
-/// constants provided. This doesn't need to handle simple things like
-/// ConstantFP comparisons, but should instead handle ConstantExprs.
-/// If we can determine that the two constants have a particular relation to
-/// each other, we should return the corresponding FCmpInst predicate,
-/// otherwise return FCmpInst::BAD_FCMP_PREDICATE. This is used below in
-/// ConstantFoldCompareInstruction.
-///
-/// To simplify this code we canonicalize the relation so that the first
-/// operand is always the most "complex" of the two.  We consider ConstantFP
-/// to be the simplest, and ConstantExprs to be the most complex.
-static FCmpInst::Predicate evaluateFCmpRelation(Constant *V1, Constant *V2) {
-  assert(V1->getType() == V2->getType() &&
-         "Cannot compare values of different types!");
-
-  // Handle degenerate case quickly
-  if (V1 == V2) return FCmpInst::FCMP_OEQ;
-
-  if (!isa<ConstantExpr>(V1)) {
-    if (!isa<ConstantExpr>(V2)) {
-      // Simple case, use the standard constant folder.
-      ConstantInt *R = nullptr;
-      R = dyn_cast<ConstantInt>(
-                      ConstantExpr::getFCmp(FCmpInst::FCMP_OEQ, V1, V2));
-      if (R && !R->isZero())
-        return FCmpInst::FCMP_OEQ;
-      R = dyn_cast<ConstantInt>(
-                      ConstantExpr::getFCmp(FCmpInst::FCMP_OLT, V1, V2));
-      if (R && !R->isZero())
-        return FCmpInst::FCMP_OLT;
-      R = dyn_cast<ConstantInt>(
-                      ConstantExpr::getFCmp(FCmpInst::FCMP_OGT, V1, V2));
-      if (R && !R->isZero())
-        return FCmpInst::FCMP_OGT;
-
-      // Nothing more we can do
-      return FCmpInst::BAD_FCMP_PREDICATE;
-    }
-
-    // If the first operand is simple and second is ConstantExpr, swap operands.
-    FCmpInst::Predicate SwappedRelation = evaluateFCmpRelation(V2, V1);
-    if (SwappedRelation != FCmpInst::BAD_FCMP_PREDICATE)
-      return FCmpInst::getSwappedPredicate(SwappedRelation);
-  } else {
-    // Ok, the LHS is known to be a constantexpr.  The RHS can be any of a
-    // constantexpr or a simple constant.
-    ConstantExpr *CE1 = cast<ConstantExpr>(V1);
-    switch (CE1->getOpcode()) {
-    case Instruction::FPTrunc:
-    case Instruction::FPExt:
-    case Instruction::UIToFP:
-    case Instruction::SIToFP:
-      // We might be able to do something with these but we don't right now.
-      break;
-    default:
-      break;
-    }
-  }
-  // There are MANY other foldings that we could perform here.  They will
-  // probably be added on demand, as they seem needed.
-  return FCmpInst::BAD_FCMP_PREDICATE;
-}
-
-static ICmpInst::Predicate areGlobalsPotentiallyEqual(const GlobalValue *GV1,
-                                                      const GlobalValue *GV2) {
-  auto isGlobalUnsafeForEquality = [](const GlobalValue *GV) {
-    if (GV->hasExternalWeakLinkage() || GV->hasWeakAnyLinkage())
-      return true;
-    if (const auto *GVar = dyn_cast<GlobalVariable>(GV)) {
-      Type *Ty = GVar->getValueType();
-      // A global with opaque type might end up being zero sized.
-      if (!Ty->isSized())
-        return true;
-      // A global with an empty type might lie at the address of any other
-      // global.
-      if (Ty->isEmptyTy())
-        return true;
-    }
-    return false;
-  };
-  // Don't try to decide equality of aliases.
-  if (!isa<GlobalAlias>(GV1) && !isa<GlobalAlias>(GV2))
-    if (!isGlobalUnsafeForEquality(GV1) && !isGlobalUnsafeForEquality(GV2))
-      return ICmpInst::ICMP_NE;
-  return ICmpInst::BAD_ICMP_PREDICATE;
-}
-
-/// This function determines if there is anything we can decide about the two
-/// constants provided. This doesn't need to handle simple things like integer
-/// comparisons, but should instead handle ConstantExprs and GlobalValues.
-/// If we can determine that the two constants have a particular relation to
-/// each other, we should return the corresponding ICmp predicate, otherwise
-/// return ICmpInst::BAD_ICMP_PREDICATE.
-///
-/// To simplify this code we canonicalize the relation so that the first
-/// operand is always the most "complex" of the two.  We consider simple
-/// constants (like ConstantInt) to be the simplest, followed by
-/// GlobalValues, followed by ConstantExpr's (the most complex).
-///
-static ICmpInst::Predicate evaluateICmpRelation(Constant *V1, Constant *V2,
-                                                bool isSigned) {
-  assert(V1->getType() == V2->getType() &&
-         "Cannot compare different types of values!");
-  if (V1 == V2) return ICmpInst::ICMP_EQ;
-
-  if (!isa<ConstantExpr>(V1) && !isa<GlobalValue>(V1) &&
-      !isa<BlockAddress>(V1)) {
-    if (!isa<GlobalValue>(V2) && !isa<ConstantExpr>(V2) &&
-        !isa<BlockAddress>(V2)) {
-      // We distilled this down to a simple case, use the standard constant
-      // folder.
-      ConstantInt *R = nullptr;
-      ICmpInst::Predicate pred = ICmpInst::ICMP_EQ;
-      R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, V1, V2));
-      if (R && !R->isZero())
-        return pred;
-      pred = isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
-      R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, V1, V2));
-      if (R && !R->isZero())
-        return pred;
-      pred = isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
-      R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, V1, V2));
-      if (R && !R->isZero())
-        return pred;
-
-      // If we couldn't figure it out, bail.
-      return ICmpInst::BAD_ICMP_PREDICATE;
-    }
-
-    // If the first operand is simple, swap operands.
-    ICmpInst::Predicate SwappedRelation =
-      evaluateICmpRelation(V2, V1, isSigned);
-    if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
-      return ICmpInst::getSwappedPredicate(SwappedRelation);
-
-  } else if (const GlobalValue *GV = dyn_cast<GlobalValue>(V1)) {
-    if (isa<ConstantExpr>(V2)) {  // Swap as necessary.
-      ICmpInst::Predicate SwappedRelation =
-        evaluateICmpRelation(V2, V1, isSigned);
-      if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
-        return ICmpInst::getSwappedPredicate(SwappedRelation);
-      return ICmpInst::BAD_ICMP_PREDICATE;
-    }
-
-    // Now we know that the RHS is a GlobalValue, BlockAddress or simple
-    // constant (which, since the types must match, means that it's a
-    // ConstantPointerNull).
-    if (const GlobalValue *GV2 = dyn_cast<GlobalValue>(V2)) {
-      return areGlobalsPotentiallyEqual(GV, GV2);
-    } else if (isa<BlockAddress>(V2)) {
-      return ICmpInst::ICMP_NE; // Globals never equal labels.
-    } else {
-      assert(isa<ConstantPointerNull>(V2) && "Canonicalization guarantee!");
-      // GlobalVals can never be null unless they have external weak linkage.
-      // We don't try to evaluate aliases here.
-      // NOTE: We should not be doing this constant folding if null pointer
-      // is considered valid for the function. But currently there is no way to
-      // query it from the Constant type.
-      if (!GV->hasExternalWeakLinkage() && !isa<GlobalAlias>(GV) &&
-          !NullPointerIsDefined(nullptr /* F */,
-                                GV->getType()->getAddressSpace()))
-        return ICmpInst::ICMP_NE;
-    }
-  } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(V1)) {
-    if (isa<ConstantExpr>(V2)) {  // Swap as necessary.
-      ICmpInst::Predicate SwappedRelation =
-        evaluateICmpRelation(V2, V1, isSigned);
-      if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
-        return ICmpInst::getSwappedPredicate(SwappedRelation);
-      return ICmpInst::BAD_ICMP_PREDICATE;
-    }
-
-    // Now we know that the RHS is a GlobalValue, BlockAddress or simple
-    // constant (which, since the types must match, means that it is a
-    // ConstantPointerNull).
-    if (const BlockAddress *BA2 = dyn_cast<BlockAddress>(V2)) {
-      // Block address in another function can't equal this one, but block
-      // addresses in the current function might be the same if blocks are
-      // empty.
-      if (BA2->getFunction() != BA->getFunction())
-        return ICmpInst::ICMP_NE;
-    } else {
-      // Block addresses aren't null, don't equal the address of globals.
-      assert((isa<ConstantPointerNull>(V2) || isa<GlobalValue>(V2)) &&
-             "Canonicalization guarantee!");
-      return ICmpInst::ICMP_NE;
-    }
-  } else {
-    // Ok, the LHS is known to be a constantexpr.  The RHS can be any of a
-    // constantexpr, a global, block address, or a simple constant.
-    ConstantExpr *CE1 = cast<ConstantExpr>(V1);
-    Constant *CE1Op0 = CE1->getOperand(0);
-
-    switch (CE1->getOpcode()) {
-    case Instruction::Trunc:
-    case Instruction::FPTrunc:
-    case Instruction::FPExt:
-    case Instruction::FPToUI:
-    case Instruction::FPToSI:
-      break; // We can't evaluate floating point casts or truncations.
-
-    case Instruction::UIToFP:
-    case Instruction::SIToFP:
-    case Instruction::BitCast:
-    case Instruction::ZExt:
-    case Instruction::SExt:
-      // We can't evaluate floating point casts or truncations.
-      if (CE1Op0->getType()->isFloatingPointTy())
-        break;
-
-      // If the cast is not actually changing bits, and the second operand is a
-      // null pointer, do the comparison with the pre-casted value.
-      if (V2->isNullValue() && CE1->getType()->isIntOrPtrTy()) {
-        if (CE1->getOpcode() == Instruction::ZExt) isSigned = false;
-        if (CE1->getOpcode() == Instruction::SExt) isSigned = true;
-        return evaluateICmpRelation(CE1Op0,
-                                    Constant::getNullValue(CE1Op0->getType()),
-                                    isSigned);
-      }
-      break;
-
-    case Instruction::GetElementPtr: {
-      GEPOperator *CE1GEP = cast<GEPOperator>(CE1);
-      // Ok, since this is a getelementptr, we know that the constant has a
-      // pointer type.  Check the various cases.
-      if (isa<ConstantPointerNull>(V2)) {
-        // If we are comparing a GEP to a null pointer, check to see if the base
-        // of the GEP equals the null pointer.
-        if (const GlobalValue *GV = dyn_cast<GlobalValue>(CE1Op0)) {
-          if (GV->hasExternalWeakLinkage())
-            // Weak linkage GVals could be zero or not. We're comparing that
-            // to null pointer so its greater-or-equal
-            return isSigned ? ICmpInst::ICMP_SGE : ICmpInst::ICMP_UGE;
-          else
-            // If its not weak linkage, the GVal must have a non-zero address
-            // so the result is greater-than
-            return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
-        } else if (isa<ConstantPointerNull>(CE1Op0)) {
-          // If we are indexing from a null pointer, check to see if we have any
-          // non-zero indices.
-          for (unsigned i = 1, e = CE1->getNumOperands(); i != e; ++i)
-            if (!CE1->getOperand(i)->isNullValue())
-              // Offsetting from null, must not be equal.
-              return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
-          // Only zero indexes from null, must still be zero.
-          return ICmpInst::ICMP_EQ;
-        }
-        // Otherwise, we can't really say if the first operand is null or not.
-      } else if (const GlobalValue *GV2 = dyn_cast<GlobalValue>(V2)) {
-        if (isa<ConstantPointerNull>(CE1Op0)) {
-          if (GV2->hasExternalWeakLinkage())
-            // Weak linkage GVals could be zero or not. We're comparing it to
-            // a null pointer, so its less-or-equal
-            return isSigned ? ICmpInst::ICMP_SLE : ICmpInst::ICMP_ULE;
-          else
-            // If its not weak linkage, the GVal must have a non-zero address
-            // so the result is less-than
-            return isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
-        } else if (const GlobalValue *GV = dyn_cast<GlobalValue>(CE1Op0)) {
-          if (GV == GV2) {
-            // If this is a getelementptr of the same global, then it must be
-            // different.  Because the types must match, the getelementptr could
-            // only have at most one index, and because we fold getelementptr's
-            // with a single zero index, it must be nonzero.
-            assert(CE1->getNumOperands() == 2 &&
-                   !CE1->getOperand(1)->isNullValue() &&
-                   "Surprising getelementptr!");
-            return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
-          } else {
-            if (CE1GEP->hasAllZeroIndices())
-              return areGlobalsPotentiallyEqual(GV, GV2);
-            return ICmpInst::BAD_ICMP_PREDICATE;
-          }
-        }
-      } else {
-        ConstantExpr *CE2 = cast<ConstantExpr>(V2);
-        Constant *CE2Op0 = CE2->getOperand(0);
-
-        // There are MANY other foldings that we could perform here.  They will
-        // probably be added on demand, as they seem needed.
-        switch (CE2->getOpcode()) {
-        default: break;
-        case Instruction::GetElementPtr:
-          // By far the most common case to handle is when the base pointers are
-          // obviously to the same global.
-          if (isa<GlobalValue>(CE1Op0) && isa<GlobalValue>(CE2Op0)) {
-            // Don't know relative ordering, but check for inequality.
-            if (CE1Op0 != CE2Op0) {
-              GEPOperator *CE2GEP = cast<GEPOperator>(CE2);
-              if (CE1GEP->hasAllZeroIndices() && CE2GEP->hasAllZeroIndices())
-                return areGlobalsPotentiallyEqual(cast<GlobalValue>(CE1Op0),
-                                                  cast<GlobalValue>(CE2Op0));
-              return ICmpInst::BAD_ICMP_PREDICATE;
-            }
-            // Ok, we know that both getelementptr instructions are based on the
-            // same global.  From this, we can precisely determine the relative
-            // ordering of the resultant pointers.
-            unsigned i = 1;
-
-            // The logic below assumes that the result of the comparison
-            // can be determined by finding the first index that differs.
-            // This doesn't work if there is over-indexing in any
-            // subsequent indices, so check for that case first.
-            if (!CE1->isGEPWithNoNotionalOverIndexing() ||
-                !CE2->isGEPWithNoNotionalOverIndexing())
-               return ICmpInst::BAD_ICMP_PREDICATE; // Might be equal.
-
-            // Compare all of the operands the GEP's have in common.
-            gep_type_iterator GTI = gep_type_begin(CE1);
-            for (;i != CE1->getNumOperands() && i != CE2->getNumOperands();
-                 ++i, ++GTI)
-              switch (IdxCompare(CE1->getOperand(i),
-                                 CE2->getOperand(i), GTI.getIndexedType())) {
-              case -1: return isSigned ? ICmpInst::ICMP_SLT:ICmpInst::ICMP_ULT;
-              case 1:  return isSigned ? ICmpInst::ICMP_SGT:ICmpInst::ICMP_UGT;
-              case -2: return ICmpInst::BAD_ICMP_PREDICATE;
-              }
-
-            // Ok, we ran out of things they have in common.  If any leftovers
-            // are non-zero then we have a difference, otherwise we are equal.
-            for (; i < CE1->getNumOperands(); ++i)
-              if (!CE1->getOperand(i)->isNullValue()) {
-                if (isa<ConstantInt>(CE1->getOperand(i)))
-                  return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
-                else
-                  return ICmpInst::BAD_ICMP_PREDICATE; // Might be equal.
-              }
-
-            for (; i < CE2->getNumOperands(); ++i)
-              if (!CE2->getOperand(i)->isNullValue()) {
-                if (isa<ConstantInt>(CE2->getOperand(i)))
-                  return isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
-                else
-                  return ICmpInst::BAD_ICMP_PREDICATE; // Might be equal.
-              }
-            return ICmpInst::ICMP_EQ;
-          }
-        }
-      }
-      break;
-    }
-    default:
-      break;
-    }
-  }
-
-  return ICmpInst::BAD_ICMP_PREDICATE;
-}
-
-Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
-                                               Constant *C1, Constant *C2) {
-  Type *ResultTy;
-  if (VectorType *VT = dyn_cast<VectorType>(C1->getType()))
-    ResultTy = VectorType::get(Type::getInt1Ty(C1->getContext()),
-                               VT->getNumElements());
-  else
-    ResultTy = Type::getInt1Ty(C1->getContext());
-
-  // Fold FCMP_FALSE/FCMP_TRUE unconditionally.
-  if (pred == FCmpInst::FCMP_FALSE)
-    return Constant::getNullValue(ResultTy);
-
-  if (pred == FCmpInst::FCMP_TRUE)
-    return Constant::getAllOnesValue(ResultTy);
-
-  // Handle some degenerate cases first
-  if (isa<UndefValue>(C1) || isa<UndefValue>(C2)) {
-    CmpInst::Predicate Predicate = CmpInst::Predicate(pred);
-    bool isIntegerPredicate = ICmpInst::isIntPredicate(Predicate);
-    // For EQ and NE, we can always pick a value for the undef to make the
-    // predicate pass or fail, so we can return undef.
-    // Also, if both operands are undef, we can return undef for int comparison.
-    if (ICmpInst::isEquality(Predicate) || (isIntegerPredicate && C1 == C2))
-      return UndefValue::get(ResultTy);
-
-    // Otherwise, for integer compare, pick the same value as the non-undef
-    // operand, and fold it to true or false.
-    if (isIntegerPredicate)
-      return ConstantInt::get(ResultTy, CmpInst::isTrueWhenEqual(Predicate));
-
-    // Choosing NaN for the undef will always make unordered comparison succeed
-    // and ordered comparison fails.
-    return ConstantInt::get(ResultTy, CmpInst::isUnordered(Predicate));
-  }
-
-  // icmp eq/ne(null,GV) -> false/true
-  if (C1->isNullValue()) {
-    if (const GlobalValue *GV = dyn_cast<GlobalValue>(C2))
-      // Don't try to evaluate aliases.  External weak GV can be null.
-      if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage() &&
-          !NullPointerIsDefined(nullptr /* F */,
-                                GV->getType()->getAddressSpace())) {
-        if (pred == ICmpInst::ICMP_EQ)
-          return ConstantInt::getFalse(C1->getContext());
-        else if (pred == ICmpInst::ICMP_NE)
-          return ConstantInt::getTrue(C1->getContext());
-      }
-  // icmp eq/ne(GV,null) -> false/true
-  } else if (C2->isNullValue()) {
-    if (const GlobalValue *GV = dyn_cast<GlobalValue>(C1))
-      // Don't try to evaluate aliases.  External weak GV can be null.
-      if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage() &&
-          !NullPointerIsDefined(nullptr /* F */,
-                                GV->getType()->getAddressSpace())) {
-        if (pred == ICmpInst::ICMP_EQ)
-          return ConstantInt::getFalse(C1->getContext());
-        else if (pred == ICmpInst::ICMP_NE)
-          return ConstantInt::getTrue(C1->getContext());
-      }
-  }
-
-  // If the comparison is a comparison between two i1's, simplify it.
-  if (C1->getType()->isIntegerTy(1)) {
-    switch(pred) {
-    case ICmpInst::ICMP_EQ:
-      if (isa<ConstantInt>(C2))
-        return ConstantExpr::getXor(C1, ConstantExpr::getNot(C2));
-      return ConstantExpr::getXor(ConstantExpr::getNot(C1), C2);
-    case ICmpInst::ICMP_NE:
-      return ConstantExpr::getXor(C1, C2);
-    default:
-      break;
-    }
-  }
-
-  if (isa<ConstantInt>(C1) && isa<ConstantInt>(C2)) {
-    const APInt &V1 = cast<ConstantInt>(C1)->getValue();
-    const APInt &V2 = cast<ConstantInt>(C2)->getValue();
-    switch (pred) {
-    default: llvm_unreachable("Invalid ICmp Predicate");
-    case ICmpInst::ICMP_EQ:  return ConstantInt::get(ResultTy, V1 == V2);
-    case ICmpInst::ICMP_NE:  return ConstantInt::get(ResultTy, V1 != V2);
-    case ICmpInst::ICMP_SLT: return ConstantInt::get(ResultTy, V1.slt(V2));
-    case ICmpInst::ICMP_SGT: return ConstantInt::get(ResultTy, V1.sgt(V2));
-    case ICmpInst::ICMP_SLE: return ConstantInt::get(ResultTy, V1.sle(V2));
-    case ICmpInst::ICMP_SGE: return ConstantInt::get(ResultTy, V1.sge(V2));
-    case ICmpInst::ICMP_ULT: return ConstantInt::get(ResultTy, V1.ult(V2));
-    case ICmpInst::ICMP_UGT: return ConstantInt::get(ResultTy, V1.ugt(V2));
-    case ICmpInst::ICMP_ULE: return ConstantInt::get(ResultTy, V1.ule(V2));
-    case ICmpInst::ICMP_UGE: return ConstantInt::get(ResultTy, V1.uge(V2));
-    }
-  } else if (isa<ConstantFP>(C1) && isa<ConstantFP>(C2)) {
-    const APFloat &C1V = cast<ConstantFP>(C1)->getValueAPF();
-    const APFloat &C2V = cast<ConstantFP>(C2)->getValueAPF();
-    APFloat::cmpResult R = C1V.compare(C2V);
-    switch (pred) {
-    default: llvm_unreachable("Invalid FCmp Predicate");
-    case FCmpInst::FCMP_FALSE: return Constant::getNullValue(ResultTy);
-    case FCmpInst::FCMP_TRUE:  return Constant::getAllOnesValue(ResultTy);
-    case FCmpInst::FCMP_UNO:
-      return ConstantInt::get(ResultTy, R==APFloat::cmpUnordered);
-    case FCmpInst::FCMP_ORD:
-      return ConstantInt::get(ResultTy, R!=APFloat::cmpUnordered);
-    case FCmpInst::FCMP_UEQ:
-      return ConstantInt::get(ResultTy, R==APFloat::cmpUnordered ||
-                                        R==APFloat::cmpEqual);
-    case FCmpInst::FCMP_OEQ:
-      return ConstantInt::get(ResultTy, R==APFloat::cmpEqual);
-    case FCmpInst::FCMP_UNE:
-      return ConstantInt::get(ResultTy, R!=APFloat::cmpEqual);
-    case FCmpInst::FCMP_ONE:
-      return ConstantInt::get(ResultTy, R==APFloat::cmpLessThan ||
-                                        R==APFloat::cmpGreaterThan);
-    case FCmpInst::FCMP_ULT:
-      return ConstantInt::get(ResultTy, R==APFloat::cmpUnordered ||
-                                        R==APFloat::cmpLessThan);
-    case FCmpInst::FCMP_OLT:
-      return ConstantInt::get(ResultTy, R==APFloat::cmpLessThan);
-    case FCmpInst::FCMP_UGT:
-      return ConstantInt::get(ResultTy, R==APFloat::cmpUnordered ||
-                                        R==APFloat::cmpGreaterThan);
-    case FCmpInst::FCMP_OGT:
-      return ConstantInt::get(ResultTy, R==APFloat::cmpGreaterThan);
-    case FCmpInst::FCMP_ULE:
-      return ConstantInt::get(ResultTy, R!=APFloat::cmpGreaterThan);
-    case FCmpInst::FCMP_OLE:
-      return ConstantInt::get(ResultTy, R==APFloat::cmpLessThan ||
-                                        R==APFloat::cmpEqual);
-    case FCmpInst::FCMP_UGE:
-      return ConstantInt::get(ResultTy, R!=APFloat::cmpLessThan);
-    case FCmpInst::FCMP_OGE:
-      return ConstantInt::get(ResultTy, R==APFloat::cmpGreaterThan ||
-                                        R==APFloat::cmpEqual);
-    }
-  } else if (C1->getType()->isVectorTy()) {
-    // If we can constant fold the comparison of each element, constant fold
-    // the whole vector comparison.
-    SmallVector<Constant*, 4> ResElts;
-    Type *Ty = IntegerType::get(C1->getContext(), 32);
-    // Compare the elements, producing an i1 result or constant expr.
-    for (unsigned i = 0, e = C1->getType()->getVectorNumElements(); i != e;++i){
-      Constant *C1E =
-        ConstantExpr::getExtractElement(C1, ConstantInt::get(Ty, i));
-      Constant *C2E =
-        ConstantExpr::getExtractElement(C2, ConstantInt::get(Ty, i));
-
-      ResElts.push_back(ConstantExpr::getCompare(pred, C1E, C2E));
-    }
-
-    return ConstantVector::get(ResElts);
-  }
-
-  if (C1->getType()->isFloatingPointTy() &&
-      // Only call evaluateFCmpRelation if we have a constant expr to avoid
-      // infinite recursive loop
-      (isa<ConstantExpr>(C1) || isa<ConstantExpr>(C2))) {
-    int Result = -1;  // -1 = unknown, 0 = known false, 1 = known true.
-    switch (evaluateFCmpRelation(C1, C2)) {
-    default: llvm_unreachable("Unknown relation!");
-    case FCmpInst::FCMP_UNO:
-    case FCmpInst::FCMP_ORD:
-    case FCmpInst::FCMP_UEQ:
-    case FCmpInst::FCMP_UNE:
-    case FCmpInst::FCMP_ULT:
-    case FCmpInst::FCMP_UGT:
-    case FCmpInst::FCMP_ULE:
-    case FCmpInst::FCMP_UGE:
-    case FCmpInst::FCMP_TRUE:
-    case FCmpInst::FCMP_FALSE:
-    case FCmpInst::BAD_FCMP_PREDICATE:
-      break; // Couldn't determine anything about these constants.
-    case FCmpInst::FCMP_OEQ: // We know that C1 == C2
-      Result = (pred == FCmpInst::FCMP_UEQ || pred == FCmpInst::FCMP_OEQ ||
-                pred == FCmpInst::FCMP_ULE || pred == FCmpInst::FCMP_OLE ||
-                pred == FCmpInst::FCMP_UGE || pred == FCmpInst::FCMP_OGE);
-      break;
-    case FCmpInst::FCMP_OLT: // We know that C1 < C2
-      Result = (pred == FCmpInst::FCMP_UNE || pred == FCmpInst::FCMP_ONE ||
-                pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT ||
-                pred == FCmpInst::FCMP_ULE || pred == FCmpInst::FCMP_OLE);
-      break;
-    case FCmpInst::FCMP_OGT: // We know that C1 > C2
-      Result = (pred == FCmpInst::FCMP_UNE || pred == FCmpInst::FCMP_ONE ||
-                pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT ||
-                pred == FCmpInst::FCMP_UGE || pred == FCmpInst::FCMP_OGE);
-      break;
-    case FCmpInst::FCMP_OLE: // We know that C1 <= C2
-      // We can only partially decide this relation.
-      if (pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT)
-        Result = 0;
-      else if (pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT)
-        Result = 1;
-      break;
-    case FCmpInst::FCMP_OGE: // We known that C1 >= C2
-      // We can only partially decide this relation.
-      if (pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT)
-        Result = 0;
-      else if (pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT)
-        Result = 1;
-      break;
-    case FCmpInst::FCMP_ONE: // We know that C1 != C2
-      // We can only partially decide this relation.
-      if (pred == FCmpInst::FCMP_OEQ || pred == FCmpInst::FCMP_UEQ)
-        Result = 0;
-      else if (pred == FCmpInst::FCMP_ONE || pred == FCmpInst::FCMP_UNE)
-        Result = 1;
-      break;
-    }
-
-    // If we evaluated the result, return it now.
-    if (Result != -1)
-      return ConstantInt::get(ResultTy, Result);
-
-  } else {
-    // Evaluate the relation between the two constants, per the predicate.
-    int Result = -1;  // -1 = unknown, 0 = known false, 1 = known true.
-    switch (evaluateICmpRelation(C1, C2,
-                                 CmpInst::isSigned((CmpInst::Predicate)pred))) {
-    default: llvm_unreachable("Unknown relational!");
-    case ICmpInst::BAD_ICMP_PREDICATE:
-      break;  // Couldn't determine anything about these constants.
-    case ICmpInst::ICMP_EQ:   // We know the constants are equal!
-      // If we know the constants are equal, we can decide the result of this
-      // computation precisely.
-      Result = ICmpInst::isTrueWhenEqual((ICmpInst::Predicate)pred);
-      break;
-    case ICmpInst::ICMP_ULT:
-      switch (pred) {
-      case ICmpInst::ICMP_ULT: case ICmpInst::ICMP_NE: case ICmpInst::ICMP_ULE:
-        Result = 1; break;
-      case ICmpInst::ICMP_UGT: case ICmpInst::ICMP_EQ: case ICmpInst::ICMP_UGE:
-        Result = 0; break;
-      }
-      break;
-    case ICmpInst::ICMP_SLT:
-      switch (pred) {
-      case ICmpInst::ICMP_SLT: case ICmpInst::ICMP_NE: case ICmpInst::ICMP_SLE:
-        Result = 1; break;
-      case ICmpInst::ICMP_SGT: case ICmpInst::ICMP_EQ: case ICmpInst::ICMP_SGE:
-        Result = 0; break;
-      }
-      break;
-    case ICmpInst::ICMP_UGT:
-      switch (pred) {
-      case ICmpInst::ICMP_UGT: case ICmpInst::ICMP_NE: case ICmpInst::ICMP_UGE:
-        Result = 1; break;
-      case ICmpInst::ICMP_ULT: case ICmpInst::ICMP_EQ: case ICmpInst::ICMP_ULE:
-        Result = 0; break;
-      }
-      break;
-    case ICmpInst::ICMP_SGT:
-      switch (pred) {
-      case ICmpInst::ICMP_SGT: case ICmpInst::ICMP_NE: case ICmpInst::ICMP_SGE:
-        Result = 1; break;
-      case ICmpInst::ICMP_SLT: case ICmpInst::ICMP_EQ: case ICmpInst::ICMP_SLE:
-        Result = 0; break;
-      }
-      break;
-    case ICmpInst::ICMP_ULE:
-      if (pred == ICmpInst::ICMP_UGT) Result = 0;
-      if (pred == ICmpInst::ICMP_ULT || pred == ICmpInst::ICMP_ULE) Result = 1;
-      break;
-    case ICmpInst::ICMP_SLE:
-      if (pred == ICmpInst::ICMP_SGT) Result = 0;
-      if (pred == ICmpInst::ICMP_SLT || pred == ICmpInst::ICMP_SLE) Result = 1;
-      break;
-    case ICmpInst::ICMP_UGE:
-      if (pred == ICmpInst::ICMP_ULT) Result = 0;
-      if (pred == ICmpInst::ICMP_UGT || pred == ICmpInst::ICMP_UGE) Result = 1;
-      break;
-    case ICmpInst::ICMP_SGE:
-      if (pred == ICmpInst::ICMP_SLT) Result = 0;
-      if (pred == ICmpInst::ICMP_SGT || pred == ICmpInst::ICMP_SGE) Result = 1;
-      break;
-    case ICmpInst::ICMP_NE:
-      if (pred == ICmpInst::ICMP_EQ) Result = 0;
-      if (pred == ICmpInst::ICMP_NE) Result = 1;
-      break;
-    }
-
-    // If we evaluated the result, return it now.
-    if (Result != -1)
-      return ConstantInt::get(ResultTy, Result);
-
-    // If the right hand side is a bitcast, try using its inverse to simplify
-    // it by moving it to the left hand side.  We can't do this if it would turn
-    // a vector compare into a scalar compare or visa versa.
-    if (ConstantExpr *CE2 = dyn_cast<ConstantExpr>(C2)) {
-      Constant *CE2Op0 = CE2->getOperand(0);
-      if (CE2->getOpcode() == Instruction::BitCast &&
-          CE2->getType()->isVectorTy() == CE2Op0->getType()->isVectorTy()) {
-        Constant *Inverse = ConstantExpr::getBitCast(C1, CE2Op0->getType());
-        return ConstantExpr::getICmp(pred, Inverse, CE2Op0);
-      }
-    }
-
-    // If the left hand side is an extension, try eliminating it.
-    if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
-      if ((CE1->getOpcode() == Instruction::SExt &&
-           ICmpInst::isSigned((ICmpInst::Predicate)pred)) ||
-          (CE1->getOpcode() == Instruction::ZExt &&
-           !ICmpInst::isSigned((ICmpInst::Predicate)pred))){
-        Constant *CE1Op0 = CE1->getOperand(0);
-        Constant *CE1Inverse = ConstantExpr::getTrunc(CE1, CE1Op0->getType());
-        if (CE1Inverse == CE1Op0) {
-          // Check whether we can safely truncate the right hand side.
-          Constant *C2Inverse = ConstantExpr::getTrunc(C2, CE1Op0->getType());
-          if (ConstantExpr::getCast(CE1->getOpcode(), C2Inverse,
-                                    C2->getType()) == C2)
-            return ConstantExpr::getICmp(pred, CE1Inverse, C2Inverse);
-        }
-      }
-    }
-
-    if ((!isa<ConstantExpr>(C1) && isa<ConstantExpr>(C2)) ||
-        (C1->isNullValue() && !C2->isNullValue())) {
-      // If C2 is a constant expr and C1 isn't, flip them around and fold the
-      // other way if possible.
-      // Also, if C1 is null and C2 isn't, flip them around.
-      pred = ICmpInst::getSwappedPredicate((ICmpInst::Predicate)pred);
-      return ConstantExpr::getICmp(pred, C2, C1);
-    }
-  }
-  return nullptr;
-}
-
-/// Test whether the given sequence of *normalized* indices is "inbounds".
-template<typename IndexTy>
-static bool isInBoundsIndices(ArrayRef<IndexTy> Idxs) {
-  // No indices means nothing that could be out of bounds.
-  if (Idxs.empty()) return true;
-
-  // If the first index is zero, it's in bounds.
-  if (cast<Constant>(Idxs[0])->isNullValue()) return true;
-
-  // If the first index is one and all the rest are zero, it's in bounds,
-  // by the one-past-the-end rule.
-  if (auto *CI = dyn_cast<ConstantInt>(Idxs[0])) {
-    if (!CI->isOne())
-      return false;
-  } else {
-    auto *CV = cast<ConstantDataVector>(Idxs[0]);
-    CI = dyn_cast_or_null<ConstantInt>(CV->getSplatValue());
-    if (!CI || !CI->isOne())
-      return false;
-  }
-
-  for (unsigned i = 1, e = Idxs.size(); i != e; ++i)
-    if (!cast<Constant>(Idxs[i])->isNullValue())
-      return false;
-  return true;
-}
-
-/// Test whether a given ConstantInt is in-range for a SequentialType.
-static bool isIndexInRangeOfArrayType(uint64_t NumElements,
-                                      const ConstantInt *CI) {
-  // We cannot bounds check the index if it doesn't fit in an int64_t.
-  if (CI->getValue().getMinSignedBits() > 64)
-    return false;
-
-  // A negative index or an index past the end of our sequential type is
-  // considered out-of-range.
-  int64_t IndexVal = CI->getSExtValue();
-  if (IndexVal < 0 || (NumElements > 0 && (uint64_t)IndexVal >= NumElements))
-    return false;
-
-  // Otherwise, it is in-range.
-  return true;
-}
-
-Constant *llvm::ConstantFoldGetElementPtr(Type *PointeeTy, Constant *C,
-                                          bool InBounds,
-                                          Optional<unsigned> InRangeIndex,
-                                          ArrayRef<Value *> Idxs) {
-  if (Idxs.empty()) return C;
-
-  Type *GEPTy = GetElementPtrInst::getGEPReturnType(
-      C, makeArrayRef((Value *const *)Idxs.data(), Idxs.size()));
-
-  if (isa<UndefValue>(C))
-    return UndefValue::get(GEPTy);
-
-  Constant *Idx0 = cast<Constant>(Idxs[0]);
-  if (Idxs.size() == 1 && (Idx0->isNullValue() || isa<UndefValue>(Idx0)))
-    return GEPTy->isVectorTy() && !C->getType()->isVectorTy()
-               ? ConstantVector::getSplat(
-                     cast<VectorType>(GEPTy)->getNumElements(), C)
-               : C;
-
-  if (C->isNullValue()) {
-    bool isNull = true;
-    for (unsigned i = 0, e = Idxs.size(); i != e; ++i)
-      if (!isa<UndefValue>(Idxs[i]) &&
-          !cast<Constant>(Idxs[i])->isNullValue()) {
-        isNull = false;
-        break;
-      }
-    if (isNull) {
-      PointerType *PtrTy = cast<PointerType>(C->getType()->getScalarType());
-      Type *Ty = GetElementPtrInst::getIndexedType(PointeeTy, Idxs);
-
-      assert(Ty && "Invalid indices for GEP!");
-      Type *OrigGEPTy = PointerType::get(Ty, PtrTy->getAddressSpace());
-      Type *GEPTy = PointerType::get(Ty, PtrTy->getAddressSpace());
-      if (VectorType *VT = dyn_cast<VectorType>(C->getType()))
-        GEPTy = VectorType::get(OrigGEPTy, VT->getNumElements());
-
-      // The GEP returns a vector of pointers when one of more of
-      // its arguments is a vector.
-      for (unsigned i = 0, e = Idxs.size(); i != e; ++i) {
-        if (auto *VT = dyn_cast<VectorType>(Idxs[i]->getType())) {
-          GEPTy = VectorType::get(OrigGEPTy, VT->getNumElements());
-          break;
-        }
-      }
-
-      return Constant::getNullValue(GEPTy);
-    }
-  }
-
-  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
-    // Combine Indices - If the source pointer to this getelementptr instruction
-    // is a getelementptr instruction, combine the indices of the two
-    // getelementptr instructions into a single instruction.
-    //
-    if (CE->getOpcode() == Instruction::GetElementPtr) {
-      gep_type_iterator LastI = gep_type_end(CE);
-      for (gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE);
-           I != E; ++I)
-        LastI = I;
-
-      // We cannot combine indices if doing so would take us outside of an
-      // array or vector.  Doing otherwise could trick us if we evaluated such a
-      // GEP as part of a load.
-      //
-      // e.g. Consider if the original GEP was:
-      // i8* getelementptr ({ [2 x i8], i32, i8, [3 x i8] }* @main.c,
-      //                    i32 0, i32 0, i64 0)
-      //
-      // If we then tried to offset it by '8' to get to the third element,
-      // an i8, we should *not* get:
-      // i8* getelementptr ({ [2 x i8], i32, i8, [3 x i8] }* @main.c,
-      //                    i32 0, i32 0, i64 8)
-      //
-      // This GEP tries to index array element '8  which runs out-of-bounds.
-      // Subsequent evaluation would get confused and produce erroneous results.
-      //
-      // The following prohibits such a GEP from being formed by checking to see
-      // if the index is in-range with respect to an array.
-      // TODO: This code may be extended to handle vectors as well.
-      bool PerformFold = false;
-      if (Idx0->isNullValue())
-        PerformFold = true;
-      else if (LastI.isSequential())
-        if (ConstantInt *CI = dyn_cast<ConstantInt>(Idx0))
-          PerformFold = (!LastI.isBoundedSequential() ||
-                         isIndexInRangeOfArrayType(
-                             LastI.getSequentialNumElements(), CI)) &&
-                        !CE->getOperand(CE->getNumOperands() - 1)
-                             ->getType()
-                             ->isVectorTy();
-
-      if (PerformFold) {
-        SmallVector<Value*, 16> NewIndices;
-        NewIndices.reserve(Idxs.size() + CE->getNumOperands());
-        NewIndices.append(CE->op_begin() + 1, CE->op_end() - 1);
-
-        // Add the last index of the source with the first index of the new GEP.
-        // Make sure to handle the case when they are actually different types.
-        Constant *Combined = CE->getOperand(CE->getNumOperands()-1);
-        // Otherwise it must be an array.
-        if (!Idx0->isNullValue()) {
-          Type *IdxTy = Combined->getType();
-          if (IdxTy != Idx0->getType()) {
-            unsigned CommonExtendedWidth =
-                std::max(IdxTy->getIntegerBitWidth(),
-                         Idx0->getType()->getIntegerBitWidth());
-            CommonExtendedWidth = std::max(CommonExtendedWidth, 64U);
-
-            Type *CommonTy =
-                Type::getIntNTy(IdxTy->getContext(), CommonExtendedWidth);
-            Constant *C1 = ConstantExpr::getSExtOrBitCast(Idx0, CommonTy);
-            Constant *C2 = ConstantExpr::getSExtOrBitCast(Combined, CommonTy);
-            Combined = ConstantExpr::get(Instruction::Add, C1, C2);
-          } else {
-            Combined =
-              ConstantExpr::get(Instruction::Add, Idx0, Combined);
-          }
-        }
-
-        NewIndices.push_back(Combined);
-        NewIndices.append(Idxs.begin() + 1, Idxs.end());
-
-        // The combined GEP normally inherits its index inrange attribute from
-        // the inner GEP, but if the inner GEP's last index was adjusted by the
-        // outer GEP, any inbounds attribute on that index is invalidated.
-        Optional<unsigned> IRIndex = cast<GEPOperator>(CE)->getInRangeIndex();
-        if (IRIndex && *IRIndex == CE->getNumOperands() - 2 && !Idx0->isNullValue())
-          IRIndex = None;
-
-        return ConstantExpr::getGetElementPtr(
-            cast<GEPOperator>(CE)->getSourceElementType(), CE->getOperand(0),
-            NewIndices, InBounds && cast<GEPOperator>(CE)->isInBounds(),
-            IRIndex);
-      }
-    }
-
-    // Attempt to fold casts to the same type away.  For example, folding:
-    //
-    //   i32* getelementptr ([2 x i32]* bitcast ([3 x i32]* %X to [2 x i32]*),
-    //                       i64 0, i64 0)
-    // into:
-    //
-    //   i32* getelementptr ([3 x i32]* %X, i64 0, i64 0)
-    //
-    // Don't fold if the cast is changing address spaces.
-    if (CE->isCast() && Idxs.size() > 1 && Idx0->isNullValue()) {
-      PointerType *SrcPtrTy =
-        dyn_cast<PointerType>(CE->getOperand(0)->getType());
-      PointerType *DstPtrTy = dyn_cast<PointerType>(CE->getType());
-      if (SrcPtrTy && DstPtrTy) {
-        ArrayType *SrcArrayTy =
-          dyn_cast<ArrayType>(SrcPtrTy->getElementType());
-        ArrayType *DstArrayTy =
-          dyn_cast<ArrayType>(DstPtrTy->getElementType());
-        if (SrcArrayTy && DstArrayTy
-            && SrcArrayTy->getElementType() == DstArrayTy->getElementType()
-            && SrcPtrTy->getAddressSpace() == DstPtrTy->getAddressSpace())
-          return ConstantExpr::getGetElementPtr(SrcArrayTy,
-                                                (Constant *)CE->getOperand(0),
-                                                Idxs, InBounds, InRangeIndex);
-      }
-    }
-  }
-
-  // Check to see if any array indices are not within the corresponding
-  // notional array or vector bounds. If so, try to determine if they can be
-  // factored out into preceding dimensions.
-  SmallVector<Constant *, 8> NewIdxs;
-  Type *Ty = PointeeTy;
-  Type *Prev = C->getType();
-  bool Unknown =
-      !isa<ConstantInt>(Idxs[0]) && !isa<ConstantDataVector>(Idxs[0]);
-  for (unsigned i = 1, e = Idxs.size(); i != e;
-       Prev = Ty, Ty = cast<CompositeType>(Ty)->getTypeAtIndex(Idxs[i]), ++i) {
-    if (!isa<ConstantInt>(Idxs[i]) && !isa<ConstantDataVector>(Idxs[i])) {
-      // We don't know if it's in range or not.
-      Unknown = true;
-      continue;
-    }
-    if (!isa<ConstantInt>(Idxs[i - 1]) && !isa<ConstantDataVector>(Idxs[i - 1]))
-      // Skip if the type of the previous index is not supported.
-      continue;
-    if (InRangeIndex && i == *InRangeIndex + 1) {
-      // If an index is marked inrange, we cannot apply this canonicalization to
-      // the following index, as that will cause the inrange index to point to
-      // the wrong element.
-      continue;
-    }
-    if (isa<StructType>(Ty)) {
-      // The verify makes sure that GEPs into a struct are in range.
-      continue;
-    }
-    auto *STy = cast<SequentialType>(Ty);
-    if (isa<VectorType>(STy)) {
-      // There can be awkward padding in after a non-power of two vector.
-      Unknown = true;
-      continue;
-    }
-    if (ConstantInt *CI = dyn_cast<ConstantInt>(Idxs[i])) {
-      if (isIndexInRangeOfArrayType(STy->getNumElements(), CI))
-        // It's in range, skip to the next index.
-        continue;
-      if (CI->getSExtValue() < 0) {
-        // It's out of range and negative, don't try to factor it.
-        Unknown = true;
-        continue;
-      }
-    } else {
-      auto *CV = cast<ConstantDataVector>(Idxs[i]);
-      bool InRange = true;
-      for (unsigned I = 0, E = CV->getNumElements(); I != E; ++I) {
-        auto *CI = cast<ConstantInt>(CV->getElementAsConstant(I));
-        InRange &= isIndexInRangeOfArrayType(STy->getNumElements(), CI);
-        if (CI->getSExtValue() < 0) {
-          Unknown = true;
-          break;
-        }
-      }
-      if (InRange || Unknown)
-        // It's in range, skip to the next index.
-        // It's out of range and negative, don't try to factor it.
-        continue;
-    }
-    if (isa<StructType>(Prev)) {
-      // It's out of range, but the prior dimension is a struct
-      // so we can't do anything about it.
-      Unknown = true;
-      continue;
-    }
-    // It's out of range, but we can factor it into the prior
-    // dimension.
-    NewIdxs.resize(Idxs.size());
-    // Determine the number of elements in our sequential type.
-    uint64_t NumElements = STy->getArrayNumElements();
-
-    // Expand the current index or the previous index to a vector from a scalar
-    // if necessary.
-    Constant *CurrIdx = cast<Constant>(Idxs[i]);
-    auto *PrevIdx =
-        NewIdxs[i - 1] ? NewIdxs[i - 1] : cast<Constant>(Idxs[i - 1]);
-    bool IsCurrIdxVector = CurrIdx->getType()->isVectorTy();
-    bool IsPrevIdxVector = PrevIdx->getType()->isVectorTy();
-    bool UseVector = IsCurrIdxVector || IsPrevIdxVector;
-
-    if (!IsCurrIdxVector && IsPrevIdxVector)
-      CurrIdx = ConstantDataVector::getSplat(
-          PrevIdx->getType()->getVectorNumElements(), CurrIdx);
-
-    if (!IsPrevIdxVector && IsCurrIdxVector)
-      PrevIdx = ConstantDataVector::getSplat(
-          CurrIdx->getType()->getVectorNumElements(), PrevIdx);
-
-    Constant *Factor =
-        ConstantInt::get(CurrIdx->getType()->getScalarType(), NumElements);
-    if (UseVector)
-      Factor = ConstantDataVector::getSplat(
-          IsPrevIdxVector ? PrevIdx->getType()->getVectorNumElements()
-                          : CurrIdx->getType()->getVectorNumElements(),
-          Factor);
-
-    NewIdxs[i] = ConstantExpr::getSRem(CurrIdx, Factor);
-
-    Constant *Div = ConstantExpr::getSDiv(CurrIdx, Factor);
-
-    unsigned CommonExtendedWidth =
-        std::max(PrevIdx->getType()->getScalarSizeInBits(),
-                 Div->getType()->getScalarSizeInBits());
-    CommonExtendedWidth = std::max(CommonExtendedWidth, 64U);
-
-    // Before adding, extend both operands to i64 to avoid
-    // overflow trouble.
-    Type *ExtendedTy = Type::getIntNTy(Div->getContext(), CommonExtendedWidth);
-    if (UseVector)
-      ExtendedTy = VectorType::get(
-          ExtendedTy, IsPrevIdxVector
-                          ? PrevIdx->getType()->getVectorNumElements()
-                          : CurrIdx->getType()->getVectorNumElements());
-
-    if (!PrevIdx->getType()->isIntOrIntVectorTy(CommonExtendedWidth))
-      PrevIdx = ConstantExpr::getSExt(PrevIdx, ExtendedTy);
-
-    if (!Div->getType()->isIntOrIntVectorTy(CommonExtendedWidth))
-      Div = ConstantExpr::getSExt(Div, ExtendedTy);
-
-    NewIdxs[i - 1] = ConstantExpr::getAdd(PrevIdx, Div);
-  }
-
-  // If we did any factoring, start over with the adjusted indices.
-  if (!NewIdxs.empty()) {
-    for (unsigned i = 0, e = Idxs.size(); i != e; ++i)
-      if (!NewIdxs[i]) NewIdxs[i] = cast<Constant>(Idxs[i]);
-    return ConstantExpr::getGetElementPtr(PointeeTy, C, NewIdxs, InBounds,
-                                          InRangeIndex);
-  }
-
-  // If all indices are known integers and normalized, we can do a simple
-  // check for the "inbounds" property.
-  if (!Unknown && !InBounds)
-    if (auto *GV = dyn_cast<GlobalVariable>(C))
-      if (!GV->hasExternalWeakLinkage() && isInBoundsIndices(Idxs))
-        return ConstantExpr::getGetElementPtr(PointeeTy, C, Idxs,
-                                              /*InBounds=*/true, InRangeIndex);
-
-  return nullptr;
-}