Remove LLVM 8.0.1 files.

1 files changed, 0 insertions, 2601 deletions

diff --git a/gnu/llvm/lib/Transforms/Scalar/GVN.cpp b/gnu/llvm/lib/Transforms/Scalar/GVN.cpp
deleted file mode 100644
index 9861948c829..00000000000
--- a/gnu/llvm/lib/Transforms/Scalar/GVN.cpp
+++ /dev/null
@@ -1,2601 +0,0 @@
-//===- GVN.cpp - Eliminate redundant values and loads ---------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This pass performs global value numbering to eliminate fully redundant
-// instructions.  It also performs simple dead load elimination.
-//
-// Note that this pass does the value numbering itself; it does not use the
-// ValueNumbering analysis passes.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Transforms/Scalar/GVN.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/Hashing.h"
-#include "llvm/ADT/MapVector.h"
-#include "llvm/ADT/PointerIntPair.h"
-#include "llvm/ADT/PostOrderIterator.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SetVector.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/AliasAnalysis.h"
-#include "llvm/Analysis/AssumptionCache.h"
-#include "llvm/Analysis/CFG.h"
-#include "llvm/Analysis/GlobalsModRef.h"
-#include "llvm/Analysis/InstructionSimplify.h"
-#include "llvm/Analysis/LoopInfo.h"
-#include "llvm/Analysis/MemoryBuiltins.h"
-#include "llvm/Analysis/MemoryDependenceAnalysis.h"
-#include "llvm/Analysis/OptimizationRemarkEmitter.h"
-#include "llvm/Analysis/PHITransAddr.h"
-#include "llvm/Analysis/TargetLibraryInfo.h"
-#include "llvm/Analysis/ValueTracking.h"
-#include "llvm/Config/llvm-config.h"
-#include "llvm/IR/Attributes.h"
-#include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CallSite.h"
-#include "llvm/IR/Constant.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/DataLayout.h"
-#include "llvm/IR/DebugLoc.h"
-#include "llvm/IR/DomTreeUpdater.h"
-#include "llvm/IR/Dominators.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/InstrTypes.h"
-#include "llvm/IR/Instruction.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/Intrinsics.h"
-#include "llvm/IR/LLVMContext.h"
-#include "llvm/IR/Metadata.h"
-#include "llvm/IR/Module.h"
-#include "llvm/IR/Operator.h"
-#include "llvm/IR/PassManager.h"
-#include "llvm/IR/PatternMatch.h"
-#include "llvm/IR/Type.h"
-#include "llvm/IR/Use.h"
-#include "llvm/IR/Value.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/Casting.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Compiler.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Transforms/Utils/SSAUpdater.h"
-#include "llvm/Transforms/Utils/VNCoercion.h"
-#include <algorithm>
-#include <cassert>
-#include <cstdint>
-#include <utility>
-#include <vector>
-
-using namespace llvm;
-using namespace llvm::gvn;
-using namespace llvm::VNCoercion;
-using namespace PatternMatch;
-
-#define DEBUG_TYPE "gvn"
-
-STATISTIC(NumGVNInstr,  "Number of instructions deleted");
-STATISTIC(NumGVNLoad,   "Number of loads deleted");
-STATISTIC(NumGVNPRE,    "Number of instructions PRE'd");
-STATISTIC(NumGVNBlocks, "Number of blocks merged");
-STATISTIC(NumGVNSimpl,  "Number of instructions simplified");
-STATISTIC(NumGVNEqProp, "Number of equalities propagated");
-STATISTIC(NumPRELoad,   "Number of loads PRE'd");
-
-static cl::opt<bool> EnablePRE("enable-pre",
-                               cl::init(true), cl::Hidden);
-static cl::opt<bool> EnableLoadPRE("enable-load-pre", cl::init(true));
-static cl::opt<bool> EnableMemDep("enable-gvn-memdep", cl::init(true));
-
-// Maximum allowed recursion depth.
-static cl::opt<uint32_t>
-MaxRecurseDepth("gvn-max-recurse-depth", cl::Hidden, cl::init(1000), cl::ZeroOrMore,
-                cl::desc("Max recurse depth in GVN (default = 1000)"));
-
-static cl::opt<uint32_t> MaxNumDeps(
-    "gvn-max-num-deps", cl::Hidden, cl::init(100), cl::ZeroOrMore,
-    cl::desc("Max number of dependences to attempt Load PRE (default = 100)"));
-
-struct llvm::GVN::Expression {
-  uint32_t opcode;
-  Type *type;
-  bool commutative = false;
-  SmallVector<uint32_t, 4> varargs;
-
-  Expression(uint32_t o = ~2U) : opcode(o) {}
-
-  bool operator==(const Expression &other) const {
-    if (opcode != other.opcode)
-      return false;
-    if (opcode == ~0U || opcode == ~1U)
-      return true;
-    if (type != other.type)
-      return false;
-    if (varargs != other.varargs)
-      return false;
-    return true;
-  }
-
-  friend hash_code hash_value(const Expression &Value) {
-    return hash_combine(
-        Value.opcode, Value.type,
-        hash_combine_range(Value.varargs.begin(), Value.varargs.end()));
-  }
-};
-
-namespace llvm {
-
-template <> struct DenseMapInfo<GVN::Expression> {
-  static inline GVN::Expression getEmptyKey() { return ~0U; }
-  static inline GVN::Expression getTombstoneKey() { return ~1U; }
-
-  static unsigned getHashValue(const GVN::Expression &e) {
-    using llvm::hash_value;
-
-    return static_cast<unsigned>(hash_value(e));
-  }
-
-  static bool isEqual(const GVN::Expression &LHS, const GVN::Expression &RHS) {
-    return LHS == RHS;
-  }
-};
-
-} // end namespace llvm
-
-/// Represents a particular available value that we know how to materialize.
-/// Materialization of an AvailableValue never fails.  An AvailableValue is
-/// implicitly associated with a rematerialization point which is the
-/// location of the instruction from which it was formed.
-struct llvm::gvn::AvailableValue {
-  enum ValType {
-    SimpleVal, // A simple offsetted value that is accessed.
-    LoadVal,   // A value produced by a load.
-    MemIntrin, // A memory intrinsic which is loaded from.
-    UndefVal   // A UndefValue representing a value from dead block (which
-               // is not yet physically removed from the CFG).
-  };
-
-  /// V - The value that is live out of the block.
-  PointerIntPair<Value *, 2, ValType> Val;
-
-  /// Offset - The byte offset in Val that is interesting for the load query.
-  unsigned Offset;
-
-  static AvailableValue get(Value *V, unsigned Offset = 0) {
-    AvailableValue Res;
-    Res.Val.setPointer(V);
-    Res.Val.setInt(SimpleVal);
-    Res.Offset = Offset;
-    return Res;
-  }
-
-  static AvailableValue getMI(MemIntrinsic *MI, unsigned Offset = 0) {
-    AvailableValue Res;
-    Res.Val.setPointer(MI);
-    Res.Val.setInt(MemIntrin);
-    Res.Offset = Offset;
-    return Res;
-  }
-
-  static AvailableValue getLoad(LoadInst *LI, unsigned Offset = 0) {
-    AvailableValue Res;
-    Res.Val.setPointer(LI);
-    Res.Val.setInt(LoadVal);
-    Res.Offset = Offset;
-    return Res;
-  }
-
-  static AvailableValue getUndef() {
-    AvailableValue Res;
-    Res.Val.setPointer(nullptr);
-    Res.Val.setInt(UndefVal);
-    Res.Offset = 0;
-    return Res;
-  }
-
-  bool isSimpleValue() const { return Val.getInt() == SimpleVal; }
-  bool isCoercedLoadValue() const { return Val.getInt() == LoadVal; }
-  bool isMemIntrinValue() const { return Val.getInt() == MemIntrin; }
-  bool isUndefValue() const { return Val.getInt() == UndefVal; }
-
-  Value *getSimpleValue() const {
-    assert(isSimpleValue() && "Wrong accessor");
-    return Val.getPointer();
-  }
-
-  LoadInst *getCoercedLoadValue() const {
-    assert(isCoercedLoadValue() && "Wrong accessor");
-    return cast<LoadInst>(Val.getPointer());
-  }
-
-  MemIntrinsic *getMemIntrinValue() const {
-    assert(isMemIntrinValue() && "Wrong accessor");
-    return cast<MemIntrinsic>(Val.getPointer());
-  }
-
-  /// Emit code at the specified insertion point to adjust the value defined
-  /// here to the specified type. This handles various coercion cases.
-  Value *MaterializeAdjustedValue(LoadInst *LI, Instruction *InsertPt,
-                                  GVN &gvn) const;
-};
-
-/// Represents an AvailableValue which can be rematerialized at the end of
-/// the associated BasicBlock.
-struct llvm::gvn::AvailableValueInBlock {
-  /// BB - The basic block in question.
-  BasicBlock *BB;
-
-  /// AV - The actual available value
-  AvailableValue AV;
-
-  static AvailableValueInBlock get(BasicBlock *BB, AvailableValue &&AV) {
-    AvailableValueInBlock Res;
-    Res.BB = BB;
-    Res.AV = std::move(AV);
-    return Res;
-  }
-
-  static AvailableValueInBlock get(BasicBlock *BB, Value *V,
-                                   unsigned Offset = 0) {
-    return get(BB, AvailableValue::get(V, Offset));
-  }
-
-  static AvailableValueInBlock getUndef(BasicBlock *BB) {
-    return get(BB, AvailableValue::getUndef());
-  }
-
-  /// Emit code at the end of this block to adjust the value defined here to
-  /// the specified type. This handles various coercion cases.
-  Value *MaterializeAdjustedValue(LoadInst *LI, GVN &gvn) const {
-    return AV.MaterializeAdjustedValue(LI, BB->getTerminator(), gvn);
-  }
-};
-
-//===----------------------------------------------------------------------===//
-//                     ValueTable Internal Functions
-//===----------------------------------------------------------------------===//
-
-GVN::Expression GVN::ValueTable::createExpr(Instruction *I) {
-  Expression e;
-  e.type = I->getType();
-  e.opcode = I->getOpcode();
-  for (Instruction::op_iterator OI = I->op_begin(), OE = I->op_end();
-       OI != OE; ++OI)
-    e.varargs.push_back(lookupOrAdd(*OI));
-  if (I->isCommutative()) {
-    // Ensure that commutative instructions that only differ by a permutation
-    // of their operands get the same value number by sorting the operand value
-    // numbers.  Since all commutative instructions have two operands it is more
-    // efficient to sort by hand rather than using, say, std::sort.
-    assert(I->getNumOperands() == 2 && "Unsupported commutative instruction!");
-    if (e.varargs[0] > e.varargs[1])
-      std::swap(e.varargs[0], e.varargs[1]);
-    e.commutative = true;
-  }
-
-  if (CmpInst *C = dyn_cast<CmpInst>(I)) {
-    // Sort the operand value numbers so x<y and y>x get the same value number.
-    CmpInst::Predicate Predicate = C->getPredicate();
-    if (e.varargs[0] > e.varargs[1]) {
-      std::swap(e.varargs[0], e.varargs[1]);
-      Predicate = CmpInst::getSwappedPredicate(Predicate);
-    }
-    e.opcode = (C->getOpcode() << 8) | Predicate;
-    e.commutative = true;
-  } else if (InsertValueInst *E = dyn_cast<InsertValueInst>(I)) {
-    for (InsertValueInst::idx_iterator II = E->idx_begin(), IE = E->idx_end();
-         II != IE; ++II)
-      e.varargs.push_back(*II);
-  }
-
-  return e;
-}
-
-GVN::Expression GVN::ValueTable::createCmpExpr(unsigned Opcode,
-                                               CmpInst::Predicate Predicate,
-                                               Value *LHS, Value *RHS) {
-  assert((Opcode == Instruction::ICmp || Opcode == Instruction::FCmp) &&
-         "Not a comparison!");
-  Expression e;
-  e.type = CmpInst::makeCmpResultType(LHS->getType());
-  e.varargs.push_back(lookupOrAdd(LHS));
-  e.varargs.push_back(lookupOrAdd(RHS));
-
-  // Sort the operand value numbers so x<y and y>x get the same value number.
-  if (e.varargs[0] > e.varargs[1]) {
-    std::swap(e.varargs[0], e.varargs[1]);
-    Predicate = CmpInst::getSwappedPredicate(Predicate);
-  }
-  e.opcode = (Opcode << 8) | Predicate;
-  e.commutative = true;
-  return e;
-}
-
-GVN::Expression GVN::ValueTable::createExtractvalueExpr(ExtractValueInst *EI) {
-  assert(EI && "Not an ExtractValueInst?");
-  Expression e;
-  e.type = EI->getType();
-  e.opcode = 0;
-
-  IntrinsicInst *I = dyn_cast<IntrinsicInst>(EI->getAggregateOperand());
-  if (I != nullptr && EI->getNumIndices() == 1 && *EI->idx_begin() == 0 ) {
-    // EI might be an extract from one of our recognised intrinsics. If it
-    // is we'll synthesize a semantically equivalent expression instead on
-    // an extract value expression.
-    switch (I->getIntrinsicID()) {
-      case Intrinsic::sadd_with_overflow:
-      case Intrinsic::uadd_with_overflow:
-        e.opcode = Instruction::Add;
-        break;
-      case Intrinsic::ssub_with_overflow:
-      case Intrinsic::usub_with_overflow:
-        e.opcode = Instruction::Sub;
-        break;
-      case Intrinsic::smul_with_overflow:
-      case Intrinsic::umul_with_overflow:
-        e.opcode = Instruction::Mul;
-        break;
-      default:
-        break;
-    }
-
-    if (e.opcode != 0) {
-      // Intrinsic recognized. Grab its args to finish building the expression.
-      assert(I->getNumArgOperands() == 2 &&
-             "Expect two args for recognised intrinsics.");
-      e.varargs.push_back(lookupOrAdd(I->getArgOperand(0)));
-      e.varargs.push_back(lookupOrAdd(I->getArgOperand(1)));
-      return e;
-    }
-  }
-
-  // Not a recognised intrinsic. Fall back to producing an extract value
-  // expression.
-  e.opcode = EI->getOpcode();
-  for (Instruction::op_iterator OI = EI->op_begin(), OE = EI->op_end();
-       OI != OE; ++OI)
-    e.varargs.push_back(lookupOrAdd(*OI));
-
-  for (ExtractValueInst::idx_iterator II = EI->idx_begin(), IE = EI->idx_end();
-         II != IE; ++II)
-    e.varargs.push_back(*II);
-
-  return e;
-}
-
-//===----------------------------------------------------------------------===//
-//                     ValueTable External Functions
-//===----------------------------------------------------------------------===//
-
-GVN::ValueTable::ValueTable() = default;
-GVN::ValueTable::ValueTable(const ValueTable &) = default;
-GVN::ValueTable::ValueTable(ValueTable &&) = default;
-GVN::ValueTable::~ValueTable() = default;
-
-/// add - Insert a value into the table with a specified value number.
-void GVN::ValueTable::add(Value *V, uint32_t num) {
-  valueNumbering.insert(std::make_pair(V, num));
-  if (PHINode *PN = dyn_cast<PHINode>(V))
-    NumberingPhi[num] = PN;
-}
-
-uint32_t GVN::ValueTable::lookupOrAddCall(CallInst *C) {
-  if (AA->doesNotAccessMemory(C)) {
-    Expression exp = createExpr(C);
-    uint32_t e = assignExpNewValueNum(exp).first;
-    valueNumbering[C] = e;
-    return e;
-  } else if (MD && AA->onlyReadsMemory(C)) {
-    Expression exp = createExpr(C);
-    auto ValNum = assignExpNewValueNum(exp);
-    if (ValNum.second) {
-      valueNumbering[C] = ValNum.first;
-      return ValNum.first;
-    }
-
-    MemDepResult local_dep = MD->getDependency(C);
-
-    if (!local_dep.isDef() && !local_dep.isNonLocal()) {
-      valueNumbering[C] =  nextValueNumber;
-      return nextValueNumber++;
-    }
-
-    if (local_dep.isDef()) {
-      CallInst* local_cdep = cast<CallInst>(local_dep.getInst());
-
-      if (local_cdep->getNumArgOperands() != C->getNumArgOperands()) {
-        valueNumbering[C] = nextValueNumber;
-        return nextValueNumber++;
-      }
-
-      for (unsigned i = 0, e = C->getNumArgOperands(); i < e; ++i) {
-        uint32_t c_vn = lookupOrAdd(C->getArgOperand(i));
-        uint32_t cd_vn = lookupOrAdd(local_cdep->getArgOperand(i));
-        if (c_vn != cd_vn) {
-          valueNumbering[C] = nextValueNumber;
-          return nextValueNumber++;
-        }
-      }
-
-      uint32_t v = lookupOrAdd(local_cdep);
-      valueNumbering[C] = v;
-      return v;
-    }
-
-    // Non-local case.
-    const MemoryDependenceResults::NonLocalDepInfo &deps =
-        MD->getNonLocalCallDependency(C);
-    // FIXME: Move the checking logic to MemDep!
-    CallInst* cdep = nullptr;
-
-    // Check to see if we have a single dominating call instruction that is
-    // identical to C.
-    for (unsigned i = 0, e = deps.size(); i != e; ++i) {
-      const NonLocalDepEntry *I = &deps[i];
-      if (I->getResult().isNonLocal())
-        continue;
-
-      // We don't handle non-definitions.  If we already have a call, reject
-      // instruction dependencies.
-      if (!I->getResult().isDef() || cdep != nullptr) {
-        cdep = nullptr;
-        break;
-      }
-
-      CallInst *NonLocalDepCall = dyn_cast<CallInst>(I->getResult().getInst());
-      // FIXME: All duplicated with non-local case.
-      if (NonLocalDepCall && DT->properlyDominates(I->getBB(), C->getParent())){
-        cdep = NonLocalDepCall;
-        continue;
-      }
-
-      cdep = nullptr;
-      break;
-    }
-
-    if (!cdep) {
-      valueNumbering[C] = nextValueNumber;
-      return nextValueNumber++;
-    }
-
-    if (cdep->getNumArgOperands() != C->getNumArgOperands()) {
-      valueNumbering[C] = nextValueNumber;
-      return nextValueNumber++;
-    }
-    for (unsigned i = 0, e = C->getNumArgOperands(); i < e; ++i) {
-      uint32_t c_vn = lookupOrAdd(C->getArgOperand(i));
-      uint32_t cd_vn = lookupOrAdd(cdep->getArgOperand(i));
-      if (c_vn != cd_vn) {
-        valueNumbering[C] = nextValueNumber;
-        return nextValueNumber++;
-      }
-    }
-
-    uint32_t v = lookupOrAdd(cdep);
-    valueNumbering[C] = v;
-    return v;
-  } else {
-    valueNumbering[C] = nextValueNumber;
-    return nextValueNumber++;
-  }
-}
-
-/// Returns true if a value number exists for the specified value.
-bool GVN::ValueTable::exists(Value *V) const { return valueNumbering.count(V) != 0; }
-
-/// lookup_or_add - Returns the value number for the specified value, assigning
-/// it a new number if it did not have one before.
-uint32_t GVN::ValueTable::lookupOrAdd(Value *V) {
-  DenseMap<Value*, uint32_t>::iterator VI = valueNumbering.find(V);
-  if (VI != valueNumbering.end())
-    return VI->second;
-
-  if (!isa<Instruction>(V)) {
-    valueNumbering[V] = nextValueNumber;
-    return nextValueNumber++;
-  }
-
-  Instruction* I = cast<Instruction>(V);
-  Expression exp;
-  switch (I->getOpcode()) {
-    case Instruction::Call:
-      return lookupOrAddCall(cast<CallInst>(I));
-    case Instruction::Add:
-    case Instruction::FAdd:
-    case Instruction::Sub:
-    case Instruction::FSub:
-    case Instruction::Mul:
-    case Instruction::FMul:
-    case Instruction::UDiv:
-    case Instruction::SDiv:
-    case Instruction::FDiv:
-    case Instruction::URem:
-    case Instruction::SRem:
-    case Instruction::FRem:
-    case Instruction::Shl:
-    case Instruction::LShr:
-    case Instruction::AShr:
-    case Instruction::And:
-    case Instruction::Or:
-    case Instruction::Xor:
-    case Instruction::ICmp:
-    case Instruction::FCmp:
-    case Instruction::Trunc:
-    case Instruction::ZExt:
-    case Instruction::SExt:
-    case Instruction::FPToUI:
-    case Instruction::FPToSI:
-    case Instruction::UIToFP:
-    case Instruction::SIToFP:
-    case Instruction::FPTrunc:
-    case Instruction::FPExt:
-    case Instruction::PtrToInt:
-    case Instruction::IntToPtr:
-    case Instruction::BitCast:
-    case Instruction::Select:
-    case Instruction::ExtractElement:
-    case Instruction::InsertElement:
-    case Instruction::ShuffleVector:
-    case Instruction::InsertValue:
-    case Instruction::GetElementPtr:
-      exp = createExpr(I);
-      break;
-    case Instruction::ExtractValue:
-      exp = createExtractvalueExpr(cast<ExtractValueInst>(I));
-      break;
-    case Instruction::PHI:
-      valueNumbering[V] = nextValueNumber;
-      NumberingPhi[nextValueNumber] = cast<PHINode>(V);
-      return nextValueNumber++;
-    default:
-      valueNumbering[V] = nextValueNumber;
-      return nextValueNumber++;
-  }
-
-  uint32_t e = assignExpNewValueNum(exp).first;
-  valueNumbering[V] = e;
-  return e;
-}
-
-/// Returns the value number of the specified value. Fails if
-/// the value has not yet been numbered.
-uint32_t GVN::ValueTable::lookup(Value *V, bool Verify) const {
-  DenseMap<Value*, uint32_t>::const_iterator VI = valueNumbering.find(V);
-  if (Verify) {
-    assert(VI != valueNumbering.end() && "Value not numbered?");
-    return VI->second;
-  }
-  return (VI != valueNumbering.end()) ? VI->second : 0;
-}
-
-/// Returns the value number of the given comparison,
-/// assigning it a new number if it did not have one before.  Useful when
-/// we deduced the result of a comparison, but don't immediately have an
-/// instruction realizing that comparison to hand.
-uint32_t GVN::ValueTable::lookupOrAddCmp(unsigned Opcode,
-                                         CmpInst::Predicate Predicate,
-                                         Value *LHS, Value *RHS) {
-  Expression exp = createCmpExpr(Opcode, Predicate, LHS, RHS);
-  return assignExpNewValueNum(exp).first;
-}
-
-/// Remove all entries from the ValueTable.
-void GVN::ValueTable::clear() {
-  valueNumbering.clear();
-  expressionNumbering.clear();
-  NumberingPhi.clear();
-  PhiTranslateTable.clear();
-  nextValueNumber = 1;
-  Expressions.clear();
-  ExprIdx.clear();
-  nextExprNumber = 0;
-}
-
-/// Remove a value from the value numbering.
-void GVN::ValueTable::erase(Value *V) {
-  uint32_t Num = valueNumbering.lookup(V);
-  valueNumbering.erase(V);
-  // If V is PHINode, V <--> value number is an one-to-one mapping.
-  if (isa<PHINode>(V))
-    NumberingPhi.erase(Num);
-}
-
-/// verifyRemoved - Verify that the value is removed from all internal data
-/// structures.
-void GVN::ValueTable::verifyRemoved(const Value *V) const {
-  for (DenseMap<Value*, uint32_t>::const_iterator
-         I = valueNumbering.begin(), E = valueNumbering.end(); I != E; ++I) {
-    assert(I->first != V && "Inst still occurs in value numbering map!");
-  }
-}
-
-//===----------------------------------------------------------------------===//
-//                                GVN Pass
-//===----------------------------------------------------------------------===//
-
-PreservedAnalyses GVN::run(Function &F, FunctionAnalysisManager &AM) {
-  // FIXME: The order of evaluation of these 'getResult' calls is very
-  // significant! Re-ordering these variables will cause GVN when run alone to
-  // be less effective! We should fix memdep and basic-aa to not exhibit this
-  // behavior, but until then don't change the order here.
-  auto &AC = AM.getResult<AssumptionAnalysis>(F);
-  auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
-  auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
-  auto &AA = AM.getResult<AAManager>(F);
-  auto &MemDep = AM.getResult<MemoryDependenceAnalysis>(F);
-  auto *LI = AM.getCachedResult<LoopAnalysis>(F);
-  auto &ORE = AM.getResult<OptimizationRemarkEmitterAnalysis>(F);
-  bool Changed = runImpl(F, AC, DT, TLI, AA, &MemDep, LI, &ORE);
-  if (!Changed)
-    return PreservedAnalyses::all();
-  PreservedAnalyses PA;
-  PA.preserve<DominatorTreeAnalysis>();
-  PA.preserve<GlobalsAA>();
-  PA.preserve<TargetLibraryAnalysis>();
-  return PA;
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-LLVM_DUMP_METHOD void GVN::dump(DenseMap<uint32_t, Value*>& d) const {
-  errs() << "{\n";
-  for (DenseMap<uint32_t, Value*>::iterator I = d.begin(),
-       E = d.end(); I != E; ++I) {
-      errs() << I->first << "\n";
-      I->second->dump();
-  }
-  errs() << "}\n";
-}
-#endif
-
-/// Return true if we can prove that the value
-/// we're analyzing is fully available in the specified block.  As we go, keep
-/// track of which blocks we know are fully alive in FullyAvailableBlocks.  This
-/// map is actually a tri-state map with the following values:
-///   0) we know the block *is not* fully available.
-///   1) we know the block *is* fully available.
-///   2) we do not know whether the block is fully available or not, but we are
-///      currently speculating that it will be.
-///   3) we are speculating for this block and have used that to speculate for
-///      other blocks.
-static bool IsValueFullyAvailableInBlock(BasicBlock *BB,
-                            DenseMap<BasicBlock*, char> &FullyAvailableBlocks,
-                            uint32_t RecurseDepth) {
-  if (RecurseDepth > MaxRecurseDepth)
-    return false;
-
-  // Optimistically assume that the block is fully available and check to see
-  // if we already know about this block in one lookup.
-  std::pair<DenseMap<BasicBlock*, char>::iterator, bool> IV =
-    FullyAvailableBlocks.insert(std::make_pair(BB, 2));
-
-  // If the entry already existed for this block, return the precomputed value.
-  if (!IV.second) {
-    // If this is a speculative "available" value, mark it as being used for
-    // speculation of other blocks.
-    if (IV.first->second == 2)
-      IV.first->second = 3;
-    return IV.first->second != 0;
-  }
-
-  // Otherwise, see if it is fully available in all predecessors.
-  pred_iterator PI = pred_begin(BB), PE = pred_end(BB);
-
-  // If this block has no predecessors, it isn't live-in here.
-  if (PI == PE)
-    goto SpeculationFailure;
-
-  for (; PI != PE; ++PI)
-    // If the value isn't fully available in one of our predecessors, then it
-    // isn't fully available in this block either.  Undo our previous
-    // optimistic assumption and bail out.
-    if (!IsValueFullyAvailableInBlock(*PI, FullyAvailableBlocks,RecurseDepth+1))
-      goto SpeculationFailure;
-
-  return true;
-
-// If we get here, we found out that this is not, after
-// all, a fully-available block.  We have a problem if we speculated on this and
-// used the speculation to mark other blocks as available.
-SpeculationFailure:
-  char &BBVal = FullyAvailableBlocks[BB];
-
-  // If we didn't speculate on this, just return with it set to false.
-  if (BBVal == 2) {
-    BBVal = 0;
-    return false;
-  }
-
-  // If we did speculate on this value, we could have blocks set to 1 that are
-  // incorrect.  Walk the (transitive) successors of this block and mark them as
-  // 0 if set to one.
-  SmallVector<BasicBlock*, 32> BBWorklist;
-  BBWorklist.push_back(BB);
-
-  do {
-    BasicBlock *Entry = BBWorklist.pop_back_val();
-    // Note that this sets blocks to 0 (unavailable) if they happen to not
-    // already be in FullyAvailableBlocks.  This is safe.
-    char &EntryVal = FullyAvailableBlocks[Entry];
-    if (EntryVal == 0) continue;  // Already unavailable.
-
-    // Mark as unavailable.
-    EntryVal = 0;
-
-    BBWorklist.append(succ_begin(Entry), succ_end(Entry));
-  } while (!BBWorklist.empty());
-
-  return false;
-}
-
-/// Given a set of loads specified by ValuesPerBlock,
-/// construct SSA form, allowing us to eliminate LI.  This returns the value
-/// that should be used at LI's definition site.
-static Value *ConstructSSAForLoadSet(LoadInst *LI,
-                         SmallVectorImpl<AvailableValueInBlock> &ValuesPerBlock,
-                                     GVN &gvn) {
-  // Check for the fully redundant, dominating load case.  In this case, we can
-  // just use the dominating value directly.
-  if (ValuesPerBlock.size() == 1 &&
-      gvn.getDominatorTree().properlyDominates(ValuesPerBlock[0].BB,
-                                               LI->getParent())) {
-    assert(!ValuesPerBlock[0].AV.isUndefValue() &&
-           "Dead BB dominate this block");
-    return ValuesPerBlock[0].MaterializeAdjustedValue(LI, gvn);
-  }
-
-  // Otherwise, we have to construct SSA form.
-  SmallVector<PHINode*, 8> NewPHIs;
-  SSAUpdater SSAUpdate(&NewPHIs);
-  SSAUpdate.Initialize(LI->getType(), LI->getName());
-
-  for (const AvailableValueInBlock &AV : ValuesPerBlock) {
-    BasicBlock *BB = AV.BB;
-
-    if (SSAUpdate.HasValueForBlock(BB))
-      continue;
-
-    // If the value is the load that we will be eliminating, and the block it's
-    // available in is the block that the load is in, then don't add it as
-    // SSAUpdater will resolve the value to the relevant phi which may let it
-    // avoid phi construction entirely if there's actually only one value.
-    if (BB == LI->getParent() &&
-        ((AV.AV.isSimpleValue() && AV.AV.getSimpleValue() == LI) ||
-         (AV.AV.isCoercedLoadValue() && AV.AV.getCoercedLoadValue() == LI)))
-      continue;
-
-    SSAUpdate.AddAvailableValue(BB, AV.MaterializeAdjustedValue(LI, gvn));
-  }
-
-  // Perform PHI construction.
-  return SSAUpdate.GetValueInMiddleOfBlock(LI->getParent());
-}
-
-Value *AvailableValue::MaterializeAdjustedValue(LoadInst *LI,
-                                                Instruction *InsertPt,
-                                                GVN &gvn) const {
-  Value *Res;
-  Type *LoadTy = LI->getType();
-  const DataLayout &DL = LI->getModule()->getDataLayout();
-  if (isSimpleValue()) {
-    Res = getSimpleValue();
-    if (Res->getType() != LoadTy) {
-      Res = getStoreValueForLoad(Res, Offset, LoadTy, InsertPt, DL);
-
-      LLVM_DEBUG(dbgs() << "GVN COERCED NONLOCAL VAL:\nOffset: " << Offset
-                        << "  " << *getSimpleValue() << '\n'
-                        << *Res << '\n'
-                        << "\n\n\n");
-    }
-  } else if (isCoercedLoadValue()) {
-    LoadInst *Load = getCoercedLoadValue();
-    if (Load->getType() == LoadTy && Offset == 0) {
-      Res = Load;
-    } else {
-      Res = getLoadValueForLoad(Load, Offset, LoadTy, InsertPt, DL);
-      // We would like to use gvn.markInstructionForDeletion here, but we can't
-      // because the load is already memoized into the leader map table that GVN
-      // tracks.  It is potentially possible to remove the load from the table,
-      // but then there all of the operations based on it would need to be
-      // rehashed.  Just leave the dead load around.
-      gvn.getMemDep().removeInstruction(Load);
-      LLVM_DEBUG(dbgs() << "GVN COERCED NONLOCAL LOAD:\nOffset: " << Offset
-                        << "  " << *getCoercedLoadValue() << '\n'
-                        << *Res << '\n'
-                        << "\n\n\n");
-    }
-  } else if (isMemIntrinValue()) {
-    Res = getMemInstValueForLoad(getMemIntrinValue(), Offset, LoadTy,
-                                 InsertPt, DL);
-    LLVM_DEBUG(dbgs() << "GVN COERCED NONLOCAL MEM INTRIN:\nOffset: " << Offset
-                      << "  " << *getMemIntrinValue() << '\n'
-                      << *Res << '\n'
-                      << "\n\n\n");
-  } else {
-    assert(isUndefValue() && "Should be UndefVal");
-    LLVM_DEBUG(dbgs() << "GVN COERCED NONLOCAL Undef:\n";);
-    return UndefValue::get(LoadTy);
-  }
-  assert(Res && "failed to materialize?");
-  return Res;
-}
-
-static bool isLifetimeStart(const Instruction *Inst) {
-  if (const IntrinsicInst* II = dyn_cast<IntrinsicInst>(Inst))
-    return II->getIntrinsicID() == Intrinsic::lifetime_start;
-  return false;
-}
-
-/// Try to locate the three instruction involved in a missed
-/// load-elimination case that is due to an intervening store.
-static void reportMayClobberedLoad(LoadInst *LI, MemDepResult DepInfo,
-                                   DominatorTree *DT,
-                                   OptimizationRemarkEmitter *ORE) {
-  using namespace ore;
-
-  User *OtherAccess = nullptr;
-
-  OptimizationRemarkMissed R(DEBUG_TYPE, "LoadClobbered", LI);
-  R << "load of type " << NV("Type", LI->getType()) << " not eliminated"
-    << setExtraArgs();
-
-  for (auto *U : LI->getPointerOperand()->users())
-    if (U != LI && (isa<LoadInst>(U) || isa<StoreInst>(U)) &&
-        DT->dominates(cast<Instruction>(U), LI)) {
-      // FIXME: for now give up if there are multiple memory accesses that
-      // dominate the load.  We need further analysis to decide which one is
-      // that we're forwarding from.
-      if (OtherAccess)
-        OtherAccess = nullptr;
-      else
-        OtherAccess = U;
-    }
-
-  if (OtherAccess)
-    R << " in favor of " << NV("OtherAccess", OtherAccess);
-
-  R << " because it is clobbered by " << NV("ClobberedBy", DepInfo.getInst());
-
-  ORE->emit(R);
-}
-
-bool GVN::AnalyzeLoadAvailability(LoadInst *LI, MemDepResult DepInfo,
-                                  Value *Address, AvailableValue &Res) {
-  assert((DepInfo.isDef() || DepInfo.isClobber()) &&
-         "expected a local dependence");
-  assert(LI->isUnordered() && "rules below are incorrect for ordered access");
-
-  const DataLayout &DL = LI->getModule()->getDataLayout();
-
-  if (DepInfo.isClobber()) {
-    // If the dependence is to a store that writes to a superset of the bits
-    // read by the load, we can extract the bits we need for the load from the
-    // stored value.
-    if (StoreInst *DepSI = dyn_cast<StoreInst>(DepInfo.getInst())) {
-      // Can't forward from non-atomic to atomic without violating memory model.
-      if (Address && LI->isAtomic() <= DepSI->isAtomic()) {
-        int Offset =
-          analyzeLoadFromClobberingStore(LI->getType(), Address, DepSI, DL);
-        if (Offset != -1) {
-          Res = AvailableValue::get(DepSI->getValueOperand(), Offset);
-          return true;
-        }
-      }
-    }
-
-    // Check to see if we have something like this:
-    //    load i32* P
-    //    load i8* (P+1)
-    // if we have this, replace the later with an extraction from the former.
-    if (LoadInst *DepLI = dyn_cast<LoadInst>(DepInfo.getInst())) {
-      // If this is a clobber and L is the first instruction in its block, then
-      // we have the first instruction in the entry block.
-      // Can't forward from non-atomic to atomic without violating memory model.
-      if (DepLI != LI && Address && LI->isAtomic() <= DepLI->isAtomic()) {
-        int Offset =
-          analyzeLoadFromClobberingLoad(LI->getType(), Address, DepLI, DL);
-
-        if (Offset != -1) {
-          Res = AvailableValue::getLoad(DepLI, Offset);
-          return true;
-        }
-      }
-    }
-
-    // If the clobbering value is a memset/memcpy/memmove, see if we can
-    // forward a value on from it.
-    if (MemIntrinsic *DepMI = dyn_cast<MemIntrinsic>(DepInfo.getInst())) {
-      if (Address && !LI->isAtomic()) {
-        int Offset = analyzeLoadFromClobberingMemInst(LI->getType(), Address,
-                                                      DepMI, DL);
-        if (Offset != -1) {
-          Res = AvailableValue::getMI(DepMI, Offset);
-          return true;
-        }
-      }
-    }
-    // Nothing known about this clobber, have to be conservative
-    LLVM_DEBUG(
-        // fast print dep, using operator<< on instruction is too slow.
-        dbgs() << "GVN: load "; LI->printAsOperand(dbgs());
-        Instruction *I = DepInfo.getInst();
-        dbgs() << " is clobbered by " << *I << '\n';);
-    if (ORE->allowExtraAnalysis(DEBUG_TYPE))
-      reportMayClobberedLoad(LI, DepInfo, DT, ORE);
-
-    return false;
-  }
-  assert(DepInfo.isDef() && "follows from above");
-
-  Instruction *DepInst = DepInfo.getInst();
-
-  // Loading the allocation -> undef.
-  if (isa<AllocaInst>(DepInst) || isMallocLikeFn(DepInst, TLI) ||
-      // Loading immediately after lifetime begin -> undef.
-      isLifetimeStart(DepInst)) {
-    Res = AvailableValue::get(UndefValue::get(LI->getType()));
-    return true;
-  }
-
-  // Loading from calloc (which zero initializes memory) -> zero
-  if (isCallocLikeFn(DepInst, TLI)) {
-    Res = AvailableValue::get(Constant::getNullValue(LI->getType()));
-    return true;
-  }
-
-  if (StoreInst *S = dyn_cast<StoreInst>(DepInst)) {
-    // Reject loads and stores that are to the same address but are of
-    // different types if we have to. If the stored value is larger or equal to
-    // the loaded value, we can reuse it.
-    if (S->getValueOperand()->getType() != LI->getType() &&
-        !canCoerceMustAliasedValueToLoad(S->getValueOperand(),
-                                         LI->getType(), DL))
-      return false;
-
-    // Can't forward from non-atomic to atomic without violating memory model.
-    if (S->isAtomic() < LI->isAtomic())
-      return false;
-
-    Res = AvailableValue::get(S->getValueOperand());
-    return true;
-  }
-
-  if (LoadInst *LD = dyn_cast<LoadInst>(DepInst)) {
-    // If the types mismatch and we can't handle it, reject reuse of the load.
-    // If the stored value is larger or equal to the loaded value, we can reuse
-    // it.
-    if (LD->getType() != LI->getType() &&
-        !canCoerceMustAliasedValueToLoad(LD, LI->getType(), DL))
-      return false;
-
-    // Can't forward from non-atomic to atomic without violating memory model.
-    if (LD->isAtomic() < LI->isAtomic())
-      return false;
-
-    Res = AvailableValue::getLoad(LD);
-    return true;
-  }
-
-  // Unknown def - must be conservative
-  LLVM_DEBUG(
-      // fast print dep, using operator<< on instruction is too slow.
-      dbgs() << "GVN: load "; LI->printAsOperand(dbgs());
-      dbgs() << " has unknown def " << *DepInst << '\n';);
-  return false;
-}
-
-void GVN::AnalyzeLoadAvailability(LoadInst *LI, LoadDepVect &Deps,
-                                  AvailValInBlkVect &ValuesPerBlock,
-                                  UnavailBlkVect &UnavailableBlocks) {
-  // Filter out useless results (non-locals, etc).  Keep track of the blocks
-  // where we have a value available in repl, also keep track of whether we see
-  // dependencies that produce an unknown value for the load (such as a call
-  // that could potentially clobber the load).
-  unsigned NumDeps = Deps.size();
-  for (unsigned i = 0, e = NumDeps; i != e; ++i) {
-    BasicBlock *DepBB = Deps[i].getBB();
-    MemDepResult DepInfo = Deps[i].getResult();
-
-    if (DeadBlocks.count(DepBB)) {
-      // Dead dependent mem-op disguise as a load evaluating the same value
-      // as the load in question.
-      ValuesPerBlock.push_back(AvailableValueInBlock::getUndef(DepBB));
-      continue;
-    }
-
-    if (!DepInfo.isDef() && !DepInfo.isClobber()) {
-      UnavailableBlocks.push_back(DepBB);
-      continue;
-    }
-
-    // The address being loaded in this non-local block may not be the same as
-    // the pointer operand of the load if PHI translation occurs.  Make sure
-    // to consider the right address.
-    Value *Address = Deps[i].getAddress();
-
-    AvailableValue AV;
-    if (AnalyzeLoadAvailability(LI, DepInfo, Address, AV)) {
-      // subtlety: because we know this was a non-local dependency, we know
-      // it's safe to materialize anywhere between the instruction within
-      // DepInfo and the end of it's block.
-      ValuesPerBlock.push_back(AvailableValueInBlock::get(DepBB,
-                                                          std::move(AV)));
-    } else {
-      UnavailableBlocks.push_back(DepBB);
-    }
-  }
-
-  assert(NumDeps == ValuesPerBlock.size() + UnavailableBlocks.size() &&
-         "post condition violation");
-}
-
-bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
-                         UnavailBlkVect &UnavailableBlocks) {
-  // Okay, we have *some* definitions of the value.  This means that the value
-  // is available in some of our (transitive) predecessors.  Lets think about
-  // doing PRE of this load.  This will involve inserting a new load into the
-  // predecessor when it's not available.  We could do this in general, but
-  // prefer to not increase code size.  As such, we only do this when we know
-  // that we only have to insert *one* load (which means we're basically moving
-  // the load, not inserting a new one).
-
-  SmallPtrSet<BasicBlock *, 4> Blockers(UnavailableBlocks.begin(),
-                                        UnavailableBlocks.end());
-
-  // Let's find the first basic block with more than one predecessor.  Walk
-  // backwards through predecessors if needed.
-  BasicBlock *LoadBB = LI->getParent();
-  BasicBlock *TmpBB = LoadBB;
-  bool IsSafeToSpeculativelyExecute = isSafeToSpeculativelyExecute(LI);
-
-  // Check that there is no implicit control flow instructions above our load in
-  // its block. If there is an instruction that doesn't always pass the
-  // execution to the following instruction, then moving through it may become
-  // invalid. For example:
-  //
-  // int arr[LEN];
-  // int index = ???;
-  // ...
-  // guard(0 <= index && index < LEN);
-  // use(arr[index]);
-  //
-  // It is illegal to move the array access to any point above the guard,
-  // because if the index is out of bounds we should deoptimize rather than
-  // access the array.
-  // Check that there is no guard in this block above our instruction.
-  if (!IsSafeToSpeculativelyExecute && ICF->isDominatedByICFIFromSameBlock(LI))
-    return false;
-  while (TmpBB->getSinglePredecessor()) {
-    TmpBB = TmpBB->getSinglePredecessor();
-    if (TmpBB == LoadBB) // Infinite (unreachable) loop.
-      return false;
-    if (Blockers.count(TmpBB))
-      return false;
-
-    // If any of these blocks has more than one successor (i.e. if the edge we
-    // just traversed was critical), then there are other paths through this
-    // block along which the load may not be anticipated.  Hoisting the load
-    // above this block would be adding the load to execution paths along
-    // which it was not previously executed.
-    if (TmpBB->getTerminator()->getNumSuccessors() != 1)
-      return false;
-
-    // Check that there is no implicit control flow in a block above.
-    if (!IsSafeToSpeculativelyExecute && ICF->hasICF(TmpBB))
-      return false;
-  }
-
-  assert(TmpBB);
-  LoadBB = TmpBB;
-
-  // Check to see how many predecessors have the loaded value fully
-  // available.
-  MapVector<BasicBlock *, Value *> PredLoads;
-  DenseMap<BasicBlock*, char> FullyAvailableBlocks;
-  for (const AvailableValueInBlock &AV : ValuesPerBlock)
-    FullyAvailableBlocks[AV.BB] = true;
-  for (BasicBlock *UnavailableBB : UnavailableBlocks)
-    FullyAvailableBlocks[UnavailableBB] = false;
-
-  SmallVector<BasicBlock *, 4> CriticalEdgePred;
-  for (BasicBlock *Pred : predecessors(LoadBB)) {
-    // If any predecessor block is an EH pad that does not allow non-PHI
-    // instructions before the terminator, we can't PRE the load.
-    if (Pred->getTerminator()->isEHPad()) {
-      LLVM_DEBUG(
-          dbgs() << "COULD NOT PRE LOAD BECAUSE OF AN EH PAD PREDECESSOR '"
-                 << Pred->getName() << "': " << *LI << '\n');
-      return false;
-    }
-
-    if (IsValueFullyAvailableInBlock(Pred, FullyAvailableBlocks, 0)) {
-      continue;
-    }
-
-    if (Pred->getTerminator()->getNumSuccessors() != 1) {
-      if (isa<IndirectBrInst>(Pred->getTerminator())) {
-        LLVM_DEBUG(
-            dbgs() << "COULD NOT PRE LOAD BECAUSE OF INDBR CRITICAL EDGE '"
-                   << Pred->getName() << "': " << *LI << '\n');
-        return false;
-      }
-
-      if (LoadBB->isEHPad()) {
-        LLVM_DEBUG(
-            dbgs() << "COULD NOT PRE LOAD BECAUSE OF AN EH PAD CRITICAL EDGE '"
-                   << Pred->getName() << "': " << *LI << '\n');
-        return false;
-      }
-
-      CriticalEdgePred.push_back(Pred);
-    } else {
-      // Only add the predecessors that will not be split for now.
-      PredLoads[Pred] = nullptr;
-    }
-  }
-
-  // Decide whether PRE is profitable for this load.
-  unsigned NumUnavailablePreds = PredLoads.size() + CriticalEdgePred.size();
-  assert(NumUnavailablePreds != 0 &&
-         "Fully available value should already be eliminated!");
-
-  // If this load is unavailable in multiple predecessors, reject it.
-  // FIXME: If we could restructure the CFG, we could make a common pred with
-  // all the preds that don't have an available LI and insert a new load into
-  // that one block.
-  if (NumUnavailablePreds != 1)
-      return false;
-
-  // Split critical edges, and update the unavailable predecessors accordingly.
-  for (BasicBlock *OrigPred : CriticalEdgePred) {
-    BasicBlock *NewPred = splitCriticalEdges(OrigPred, LoadBB);
-    assert(!PredLoads.count(OrigPred) && "Split edges shouldn't be in map!");
-    PredLoads[NewPred] = nullptr;
-    LLVM_DEBUG(dbgs() << "Split critical edge " << OrigPred->getName() << "->"
-                      << LoadBB->getName() << '\n');
-  }
-
-  // Check if the load can safely be moved to all the unavailable predecessors.
-  bool CanDoPRE = true;
-  const DataLayout &DL = LI->getModule()->getDataLayout();
-  SmallVector<Instruction*, 8> NewInsts;
-  for (auto &PredLoad : PredLoads) {
-    BasicBlock *UnavailablePred = PredLoad.first;
-
-    // Do PHI translation to get its value in the predecessor if necessary.  The
-    // returned pointer (if non-null) is guaranteed to dominate UnavailablePred.
-
-    // If all preds have a single successor, then we know it is safe to insert
-    // the load on the pred (?!?), so we can insert code to materialize the
-    // pointer if it is not available.
-    PHITransAddr Address(LI->getPointerOperand(), DL, AC);
-    Value *LoadPtr = nullptr;
-    LoadPtr = Address.PHITranslateWithInsertion(LoadBB, UnavailablePred,
-                                                *DT, NewInsts);
-
-    // If we couldn't find or insert a computation of this phi translated value,
-    // we fail PRE.
-    if (!LoadPtr) {
-      LLVM_DEBUG(dbgs() << "COULDN'T INSERT PHI TRANSLATED VALUE OF: "
-                        << *LI->getPointerOperand() << "\n");
-      CanDoPRE = false;
-      break;
-    }
-
-    PredLoad.second = LoadPtr;
-  }
-
-  if (!CanDoPRE) {
-    while (!NewInsts.empty()) {
-      Instruction *I = NewInsts.pop_back_val();
-      markInstructionForDeletion(I);
-    }
-    // HINT: Don't revert the edge-splitting as following transformation may
-    // also need to split these critical edges.
-    return !CriticalEdgePred.empty();
-  }
-
-  // Okay, we can eliminate this load by inserting a reload in the predecessor
-  // and using PHI construction to get the value in the other predecessors, do
-  // it.
-  LLVM_DEBUG(dbgs() << "GVN REMOVING PRE LOAD: " << *LI << '\n');
-  LLVM_DEBUG(if (!NewInsts.empty()) dbgs()
-             << "INSERTED " << NewInsts.size() << " INSTS: " << *NewInsts.back()
-             << '\n');
-
-  // Assign value numbers to the new instructions.
-  for (Instruction *I : NewInsts) {
-    // Instructions that have been inserted in predecessor(s) to materialize
-    // the load address do not retain their original debug locations. Doing
-    // so could lead to confusing (but correct) source attributions.
-    // FIXME: How do we retain source locations without causing poor debugging
-    // behavior?
-    I->setDebugLoc(DebugLoc());
-
-    // FIXME: We really _ought_ to insert these value numbers into their
-    // parent's availability map.  However, in doing so, we risk getting into
-    // ordering issues.  If a block hasn't been processed yet, we would be
-    // marking a value as AVAIL-IN, which isn't what we intend.
-    VN.lookupOrAdd(I);
-  }
-
-  for (const auto &PredLoad : PredLoads) {
-    BasicBlock *UnavailablePred = PredLoad.first;
-    Value *LoadPtr = PredLoad.second;
-
-    auto *NewLoad = new LoadInst(LoadPtr, LI->getName()+".pre",
-                                 LI->isVolatile(), LI->getAlignment(),
-                                 LI->getOrdering(), LI->getSyncScopeID(),
-                                 UnavailablePred->getTerminator());
-    NewLoad->setDebugLoc(LI->getDebugLoc());
-
-    // Transfer the old load's AA tags to the new load.
-    AAMDNodes Tags;
-    LI->getAAMetadata(Tags);
-    if (Tags)
-      NewLoad->setAAMetadata(Tags);
-
-    if (auto *MD = LI->getMetadata(LLVMContext::MD_invariant_load))
-      NewLoad->setMetadata(LLVMContext::MD_invariant_load, MD);
-    if (auto *InvGroupMD = LI->getMetadata(LLVMContext::MD_invariant_group))
-      NewLoad->setMetadata(LLVMContext::MD_invariant_group, InvGroupMD);
-    if (auto *RangeMD = LI->getMetadata(LLVMContext::MD_range))
-      NewLoad->setMetadata(LLVMContext::MD_range, RangeMD);
-
-    // We do not propagate the old load's debug location, because the new
-    // load now lives in a different BB, and we want to avoid a jumpy line
-    // table.
-    // FIXME: How do we retain source locations without causing poor debugging
-    // behavior?
-
-    // Add the newly created load.
-    ValuesPerBlock.push_back(AvailableValueInBlock::get(UnavailablePred,
-                                                        NewLoad));
-    MD->invalidateCachedPointerInfo(LoadPtr);
-    LLVM_DEBUG(dbgs() << "GVN INSERTED " << *NewLoad << '\n');
-  }
-
-  // Perform PHI construction.
-  Value *V = ConstructSSAForLoadSet(LI, ValuesPerBlock, *this);
-  LI->replaceAllUsesWith(V);
-  if (isa<PHINode>(V))
-    V->takeName(LI);
-  if (Instruction *I = dyn_cast<Instruction>(V))
-    I->setDebugLoc(LI->getDebugLoc());
-  if (V->getType()->isPtrOrPtrVectorTy())
-    MD->invalidateCachedPointerInfo(V);
-  markInstructionForDeletion(LI);
-  ORE->emit([&]() {
-    return OptimizationRemark(DEBUG_TYPE, "LoadPRE", LI)
-           << "load eliminated by PRE";
-  });
-  ++NumPRELoad;
-  return true;
-}
-
-static void reportLoadElim(LoadInst *LI, Value *AvailableValue,
-                           OptimizationRemarkEmitter *ORE) {
-  using namespace ore;
-
-  ORE->emit([&]() {
-    return OptimizationRemark(DEBUG_TYPE, "LoadElim", LI)
-           << "load of type " << NV("Type", LI->getType()) << " eliminated"
-           << setExtraArgs() << " in favor of "
-           << NV("InfavorOfValue", AvailableValue);
-  });
-}
-
-/// Attempt to eliminate a load whose dependencies are
-/// non-local by performing PHI construction.
-bool GVN::processNonLocalLoad(LoadInst *LI) {
-  // non-local speculations are not allowed under asan.
-  if (LI->getParent()->getParent()->hasFnAttribute(
-          Attribute::SanitizeAddress) ||
-      LI->getParent()->getParent()->hasFnAttribute(
-          Attribute::SanitizeHWAddress))
-    return false;
-
-  // Step 1: Find the non-local dependencies of the load.
-  LoadDepVect Deps;
-  MD->getNonLocalPointerDependency(LI, Deps);
-
-  // If we had to process more than one hundred blocks to find the
-  // dependencies, this load isn't worth worrying about.  Optimizing
-  // it will be too expensive.
-  unsigned NumDeps = Deps.size();
-  if (NumDeps > MaxNumDeps)
-    return false;
-
-  // If we had a phi translation failure, we'll have a single entry which is a
-  // clobber in the current block.  Reject this early.
-  if (NumDeps == 1 &&
-      !Deps[0].getResult().isDef() && !Deps[0].getResult().isClobber()) {
-    LLVM_DEBUG(dbgs() << "GVN: non-local load "; LI->printAsOperand(dbgs());
-               dbgs() << " has unknown dependencies\n";);
-    return false;
-  }
-
-  // If this load follows a GEP, see if we can PRE the indices before analyzing.
-  if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(LI->getOperand(0))) {
-    for (GetElementPtrInst::op_iterator OI = GEP->idx_begin(),
-                                        OE = GEP->idx_end();
-         OI != OE; ++OI)
-      if (Instruction *I = dyn_cast<Instruction>(OI->get()))
-        performScalarPRE(I);
-  }
-
-  // Step 2: Analyze the availability of the load
-  AvailValInBlkVect ValuesPerBlock;
-  UnavailBlkVect UnavailableBlocks;
-  AnalyzeLoadAvailability(LI, Deps, ValuesPerBlock, UnavailableBlocks);
-
-  // If we have no predecessors that produce a known value for this load, exit
-  // early.
-  if (ValuesPerBlock.empty())
-    return false;
-
-  // Step 3: Eliminate fully redundancy.
-  //
-  // If all of the instructions we depend on produce a known value for this
-  // load, then it is fully redundant and we can use PHI insertion to compute
-  // its value.  Insert PHIs and remove the fully redundant value now.
-  if (UnavailableBlocks.empty()) {
-    LLVM_DEBUG(dbgs() << "GVN REMOVING NONLOCAL LOAD: " << *LI << '\n');
-
-    // Perform PHI construction.
-    Value *V = ConstructSSAForLoadSet(LI, ValuesPerBlock, *this);
-    LI->replaceAllUsesWith(V);
-
-    if (isa<PHINode>(V))
-      V->takeName(LI);
-    if (Instruction *I = dyn_cast<Instruction>(V))
-      // If instruction I has debug info, then we should not update it.
-      // Also, if I has a null DebugLoc, then it is still potentially incorrect
-      // to propagate LI's DebugLoc because LI may not post-dominate I.
-      if (LI->getDebugLoc() && LI->getParent() == I->getParent())
-        I->setDebugLoc(LI->getDebugLoc());
-    if (V->getType()->isPtrOrPtrVectorTy())
-      MD->invalidateCachedPointerInfo(V);
-    markInstructionForDeletion(LI);
-    ++NumGVNLoad;
-    reportLoadElim(LI, V, ORE);
-    return true;
-  }
-
-  // Step 4: Eliminate partial redundancy.
-  if (!EnablePRE || !EnableLoadPRE)
-    return false;
-
-  return PerformLoadPRE(LI, ValuesPerBlock, UnavailableBlocks);
-}
-
-bool GVN::processAssumeIntrinsic(IntrinsicInst *IntrinsicI) {
-  assert(IntrinsicI->getIntrinsicID() == Intrinsic::assume &&
-         "This function can only be called with llvm.assume intrinsic");
-  Value *V = IntrinsicI->getArgOperand(0);
-
-  if (ConstantInt *Cond = dyn_cast<ConstantInt>(V)) {
-    if (Cond->isZero()) {
-      Type *Int8Ty = Type::getInt8Ty(V->getContext());
-      // Insert a new store to null instruction before the load to indicate that
-      // this code is not reachable.  FIXME: We could insert unreachable
-      // instruction directly because we can modify the CFG.
-      new StoreInst(UndefValue::get(Int8Ty),
-                    Constant::getNullValue(Int8Ty->getPointerTo()),
-                    IntrinsicI);
-    }
-    markInstructionForDeletion(IntrinsicI);
-    return false;
-  } else if (isa<Constant>(V)) {
-    // If it's not false, and constant, it must evaluate to true. This means our
-    // assume is assume(true), and thus, pointless, and we don't want to do
-    // anything more here.
-    return false;
-  }
-
-  Constant *True = ConstantInt::getTrue(V->getContext());
-  bool Changed = false;
-
-  for (BasicBlock *Successor : successors(IntrinsicI->getParent())) {
-    BasicBlockEdge Edge(IntrinsicI->getParent(), Successor);
-
-    // This property is only true in dominated successors, propagateEquality
-    // will check dominance for us.
-    Changed |= propagateEquality(V, True, Edge, false);
-  }
-
-  // We can replace assume value with true, which covers cases like this:
-  // call void @llvm.assume(i1 %cmp)
-  // br i1 %cmp, label %bb1, label %bb2 ; will change %cmp to true
-  ReplaceWithConstMap[V] = True;
-
-  // If one of *cmp *eq operand is const, adding it to map will cover this:
-  // %cmp = fcmp oeq float 3.000000e+00, %0 ; const on lhs could happen
-  // call void @llvm.assume(i1 %cmp)
-  // ret float %0 ; will change it to ret float 3.000000e+00
-  if (auto *CmpI = dyn_cast<CmpInst>(V)) {
-    if (CmpI->getPredicate() == CmpInst::Predicate::ICMP_EQ ||
-        CmpI->getPredicate() == CmpInst::Predicate::FCMP_OEQ ||
-        (CmpI->getPredicate() == CmpInst::Predicate::FCMP_UEQ &&
-         CmpI->getFastMathFlags().noNaNs())) {
-      Value *CmpLHS = CmpI->getOperand(0);
-      Value *CmpRHS = CmpI->getOperand(1);
-      if (isa<Constant>(CmpLHS))
-        std::swap(CmpLHS, CmpRHS);
-      auto *RHSConst = dyn_cast<Constant>(CmpRHS);
-
-      // If only one operand is constant.
-      if (RHSConst != nullptr && !isa<Constant>(CmpLHS))
-        ReplaceWithConstMap[CmpLHS] = RHSConst;
-    }
-  }
-  return Changed;
-}
-
-static void patchAndReplaceAllUsesWith(Instruction *I, Value *Repl) {
-  patchReplacementInstruction(I, Repl);
-  I->replaceAllUsesWith(Repl);
-}
-
-/// Attempt to eliminate a load, first by eliminating it
-/// locally, and then attempting non-local elimination if that fails.
-bool GVN::processLoad(LoadInst *L) {
-  if (!MD)
-    return false;
-
-  // This code hasn't been audited for ordered or volatile memory access
-  if (!L->isUnordered())
-    return false;
-
-  if (L->use_empty()) {
-    markInstructionForDeletion(L);
-    return true;
-  }
-
-  // ... to a pointer that has been loaded from before...
-  MemDepResult Dep = MD->getDependency(L);
-
-  // If it is defined in another block, try harder.
-  if (Dep.isNonLocal())
-    return processNonLocalLoad(L);
-
-  // Only handle the local case below
-  if (!Dep.isDef() && !Dep.isClobber()) {
-    // This might be a NonFuncLocal or an Unknown
-    LLVM_DEBUG(
-        // fast print dep, using operator<< on instruction is too slow.
-        dbgs() << "GVN: load "; L->printAsOperand(dbgs());
-        dbgs() << " has unknown dependence\n";);
-    return false;
-  }
-
-  AvailableValue AV;
-  if (AnalyzeLoadAvailability(L, Dep, L->getPointerOperand(), AV)) {
-    Value *AvailableValue = AV.MaterializeAdjustedValue(L, L, *this);
-
-    // Replace the load!
-    patchAndReplaceAllUsesWith(L, AvailableValue);
-    markInstructionForDeletion(L);
-    ++NumGVNLoad;
-    reportLoadElim(L, AvailableValue, ORE);
-    // Tell MDA to rexamine the reused pointer since we might have more
-    // information after forwarding it.
-    if (MD && AvailableValue->getType()->isPtrOrPtrVectorTy())
-      MD->invalidateCachedPointerInfo(AvailableValue);
-    return true;
-  }
-
-  return false;
-}
-
-/// Return a pair the first field showing the value number of \p Exp and the
-/// second field showing whether it is a value number newly created.
-std::pair<uint32_t, bool>
-GVN::ValueTable::assignExpNewValueNum(Expression &Exp) {
-  uint32_t &e = expressionNumbering[Exp];
-  bool CreateNewValNum = !e;
-  if (CreateNewValNum) {
-    Expressions.push_back(Exp);
-    if (ExprIdx.size() < nextValueNumber + 1)
-      ExprIdx.resize(nextValueNumber * 2);
-    e = nextValueNumber;
-    ExprIdx[nextValueNumber++] = nextExprNumber++;
-  }
-  return {e, CreateNewValNum};
-}
-
-/// Return whether all the values related with the same \p num are
-/// defined in \p BB.
-bool GVN::ValueTable::areAllValsInBB(uint32_t Num, const BasicBlock *BB,
-                                     GVN &Gvn) {
-  LeaderTableEntry *Vals = &Gvn.LeaderTable[Num];
-  while (Vals && Vals->BB == BB)
-    Vals = Vals->Next;
-  return !Vals;
-}
-
-/// Wrap phiTranslateImpl to provide caching functionality.
-uint32_t GVN::ValueTable::phiTranslate(const BasicBlock *Pred,
-                                       const BasicBlock *PhiBlock, uint32_t Num,
-                                       GVN &Gvn) {
-  auto FindRes = PhiTranslateTable.find({Num, Pred});
-  if (FindRes != PhiTranslateTable.end())
-    return FindRes->second;
-  uint32_t NewNum = phiTranslateImpl(Pred, PhiBlock, Num, Gvn);
-  PhiTranslateTable.insert({{Num, Pred}, NewNum});
-  return NewNum;
-}
-
-/// Translate value number \p Num using phis, so that it has the values of
-/// the phis in BB.
-uint32_t GVN::ValueTable::phiTranslateImpl(const BasicBlock *Pred,
-                                           const BasicBlock *PhiBlock,
-                                           uint32_t Num, GVN &Gvn) {
-  if (PHINode *PN = NumberingPhi[Num]) {
-    for (unsigned i = 0; i != PN->getNumIncomingValues(); ++i) {
-      if (PN->getParent() == PhiBlock && PN->getIncomingBlock(i) == Pred)
-        if (uint32_t TransVal = lookup(PN->getIncomingValue(i), false))
-          return TransVal;
-    }
-    return Num;
-  }
-
-  // If there is any value related with Num is defined in a BB other than
-  // PhiBlock, it cannot depend on a phi in PhiBlock without going through
-  // a backedge. We can do an early exit in that case to save compile time.
-  if (!areAllValsInBB(Num, PhiBlock, Gvn))
-    return Num;
-
-  if (Num >= ExprIdx.size() || ExprIdx[Num] == 0)
-    return Num;
-  Expression Exp = Expressions[ExprIdx[Num]];
-
-  for (unsigned i = 0; i < Exp.varargs.size(); i++) {
-    // For InsertValue and ExtractValue, some varargs are index numbers
-    // instead of value numbers. Those index numbers should not be
-    // translated.
-    if ((i > 1 && Exp.opcode == Instruction::InsertValue) ||
-        (i > 0 && Exp.opcode == Instruction::ExtractValue))
-      continue;
-    Exp.varargs[i] = phiTranslate(Pred, PhiBlock, Exp.varargs[i], Gvn);
-  }
-
-  if (Exp.commutative) {
-    assert(Exp.varargs.size() == 2 && "Unsupported commutative expression!");
-    if (Exp.varargs[0] > Exp.varargs[1]) {
-      std::swap(Exp.varargs[0], Exp.varargs[1]);
-      uint32_t Opcode = Exp.opcode >> 8;
-      if (Opcode == Instruction::ICmp || Opcode == Instruction::FCmp)
-        Exp.opcode = (Opcode << 8) |
-                     CmpInst::getSwappedPredicate(
-                         static_cast<CmpInst::Predicate>(Exp.opcode & 255));
-    }
-  }
-
-  if (uint32_t NewNum = expressionNumbering[Exp])
-    return NewNum;
-  return Num;
-}
-
-/// Erase stale entry from phiTranslate cache so phiTranslate can be computed
-/// again.
-void GVN::ValueTable::eraseTranslateCacheEntry(uint32_t Num,
-                                               const BasicBlock &CurrBlock) {
-  for (const BasicBlock *Pred : predecessors(&CurrBlock)) {
-    auto FindRes = PhiTranslateTable.find({Num, Pred});
-    if (FindRes != PhiTranslateTable.end())
-      PhiTranslateTable.erase(FindRes);
-  }
-}
-
-// In order to find a leader for a given value number at a
-// specific basic block, we first obtain the list of all Values for that number,
-// and then scan the list to find one whose block dominates the block in
-// question.  This is fast because dominator tree queries consist of only
-// a few comparisons of DFS numbers.
-Value *GVN::findLeader(const BasicBlock *BB, uint32_t num) {
-  LeaderTableEntry Vals = LeaderTable[num];
-  if (!Vals.Val) return nullptr;
-
-  Value *Val = nullptr;
-  if (DT->dominates(Vals.BB, BB)) {
-    Val = Vals.Val;
-    if (isa<Constant>(Val)) return Val;
-  }
-
-  LeaderTableEntry* Next = Vals.Next;
-  while (Next) {
-    if (DT->dominates(Next->BB, BB)) {
-      if (isa<Constant>(Next->Val)) return Next->Val;
-      if (!Val) Val = Next->Val;
-    }
-
-    Next = Next->Next;
-  }
-
-  return Val;
-}
-
-/// There is an edge from 'Src' to 'Dst'.  Return
-/// true if every path from the entry block to 'Dst' passes via this edge.  In
-/// particular 'Dst' must not be reachable via another edge from 'Src'.
-static bool isOnlyReachableViaThisEdge(const BasicBlockEdge &E,
-                                       DominatorTree *DT) {
-  // While in theory it is interesting to consider the case in which Dst has
-  // more than one predecessor, because Dst might be part of a loop which is
-  // only reachable from Src, in practice it is pointless since at the time
-  // GVN runs all such loops have preheaders, which means that Dst will have
-  // been changed to have only one predecessor, namely Src.
-  const BasicBlock *Pred = E.getEnd()->getSinglePredecessor();
-  assert((!Pred || Pred == E.getStart()) &&
-         "No edge between these basic blocks!");
-  return Pred != nullptr;
-}
-
-void GVN::assignBlockRPONumber(Function &F) {
-  BlockRPONumber.clear();
-  uint32_t NextBlockNumber = 1;
-  ReversePostOrderTraversal<Function *> RPOT(&F);
-  for (BasicBlock *BB : RPOT)
-    BlockRPONumber[BB] = NextBlockNumber++;
-  InvalidBlockRPONumbers = false;
-}
-
-// Tries to replace instruction with const, using information from
-// ReplaceWithConstMap.
-bool GVN::replaceOperandsWithConsts(Instruction *Instr) const {
-  bool Changed = false;
-  for (unsigned OpNum = 0; OpNum < Instr->getNumOperands(); ++OpNum) {
-    Value *Operand = Instr->getOperand(OpNum);
-    auto it = ReplaceWithConstMap.find(Operand);
-    if (it != ReplaceWithConstMap.end()) {
-      assert(!isa<Constant>(Operand) &&
-             "Replacing constants with constants is invalid");
-      LLVM_DEBUG(dbgs() << "GVN replacing: " << *Operand << " with "
-                        << *it->second << " in instruction " << *Instr << '\n');
-      Instr->setOperand(OpNum, it->second);
-      Changed = true;
-    }
-  }
-  return Changed;
-}
-
-/// The given values are known to be equal in every block
-/// dominated by 'Root'.  Exploit this, for example by replacing 'LHS' with
-/// 'RHS' everywhere in the scope.  Returns whether a change was made.
-/// If DominatesByEdge is false, then it means that we will propagate the RHS
-/// value starting from the end of Root.Start.
-bool GVN::propagateEquality(Value *LHS, Value *RHS, const BasicBlockEdge &Root,
-                            bool DominatesByEdge) {
-  SmallVector<std::pair<Value*, Value*>, 4> Worklist;
-  Worklist.push_back(std::make_pair(LHS, RHS));
-  bool Changed = false;
-  // For speed, compute a conservative fast approximation to
-  // DT->dominates(Root, Root.getEnd());
-  const bool RootDominatesEnd = isOnlyReachableViaThisEdge(Root, DT);
-
-  while (!Worklist.empty()) {
-    std::pair<Value*, Value*> Item = Worklist.pop_back_val();
-    LHS = Item.first; RHS = Item.second;
-
-    if (LHS == RHS)
-      continue;
-    assert(LHS->getType() == RHS->getType() && "Equality but unequal types!");
-
-    // Don't try to propagate equalities between constants.
-    if (isa<Constant>(LHS) && isa<Constant>(RHS))
-      continue;
-
-    // Prefer a constant on the right-hand side, or an Argument if no constants.
-    if (isa<Constant>(LHS) || (isa<Argument>(LHS) && !isa<Constant>(RHS)))
-      std::swap(LHS, RHS);
-    assert((isa<Argument>(LHS) || isa<Instruction>(LHS)) && "Unexpected value!");
-
-    // If there is no obvious reason to prefer the left-hand side over the
-    // right-hand side, ensure the longest lived term is on the right-hand side,
-    // so the shortest lived term will be replaced by the longest lived.
-    // This tends to expose more simplifications.
-    uint32_t LVN = VN.lookupOrAdd(LHS);
-    if ((isa<Argument>(LHS) && isa<Argument>(RHS)) ||
-        (isa<Instruction>(LHS) && isa<Instruction>(RHS))) {
-      // Move the 'oldest' value to the right-hand side, using the value number
-      // as a proxy for age.
-      uint32_t RVN = VN.lookupOrAdd(RHS);
-      if (LVN < RVN) {
-        std::swap(LHS, RHS);
-        LVN = RVN;
-      }
-    }
-
-    // If value numbering later sees that an instruction in the scope is equal
-    // to 'LHS' then ensure it will be turned into 'RHS'.  In order to preserve
-    // the invariant that instructions only occur in the leader table for their
-    // own value number (this is used by removeFromLeaderTable), do not do this
-    // if RHS is an instruction (if an instruction in the scope is morphed into
-    // LHS then it will be turned into RHS by the next GVN iteration anyway, so
-    // using the leader table is about compiling faster, not optimizing better).
-    // The leader table only tracks basic blocks, not edges. Only add to if we
-    // have the simple case where the edge dominates the end.
-    if (RootDominatesEnd && !isa<Instruction>(RHS))
-      addToLeaderTable(LVN, RHS, Root.getEnd());
-
-    // Replace all occurrences of 'LHS' with 'RHS' everywhere in the scope.  As
-    // LHS always has at least one use that is not dominated by Root, this will
-    // never do anything if LHS has only one use.
-    if (!LHS->hasOneUse()) {
-      unsigned NumReplacements =
-          DominatesByEdge
-              ? replaceDominatedUsesWith(LHS, RHS, *DT, Root)
-              : replaceDominatedUsesWith(LHS, RHS, *DT, Root.getStart());
-
-      Changed |= NumReplacements > 0;
-      NumGVNEqProp += NumReplacements;
-      // Cached information for anything that uses LHS will be invalid.
-      if (MD)
-        MD->invalidateCachedPointerInfo(LHS);
-    }
-
-    // Now try to deduce additional equalities from this one. For example, if
-    // the known equality was "(A != B)" == "false" then it follows that A and B
-    // are equal in the scope. Only boolean equalities with an explicit true or
-    // false RHS are currently supported.
-    if (!RHS->getType()->isIntegerTy(1))
-      // Not a boolean equality - bail out.
-      continue;
-    ConstantInt *CI = dyn_cast<ConstantInt>(RHS);
-    if (!CI)
-      // RHS neither 'true' nor 'false' - bail out.
-      continue;
-    // Whether RHS equals 'true'.  Otherwise it equals 'false'.
-    bool isKnownTrue = CI->isMinusOne();
-    bool isKnownFalse = !isKnownTrue;
-
-    // If "A && B" is known true then both A and B are known true.  If "A || B"
-    // is known false then both A and B are known false.
-    Value *A, *B;
-    if ((isKnownTrue && match(LHS, m_And(m_Value(A), m_Value(B)))) ||
-        (isKnownFalse && match(LHS, m_Or(m_Value(A), m_Value(B))))) {
-      Worklist.push_back(std::make_pair(A, RHS));
-      Worklist.push_back(std::make_pair(B, RHS));
-      continue;
-    }
-
-    // If we are propagating an equality like "(A == B)" == "true" then also
-    // propagate the equality A == B.  When propagating a comparison such as
-    // "(A >= B)" == "true", replace all instances of "A < B" with "false".
-    if (CmpInst *Cmp = dyn_cast<CmpInst>(LHS)) {
-      Value *Op0 = Cmp->getOperand(0), *Op1 = Cmp->getOperand(1);
-
-      // If "A == B" is known true, or "A != B" is known false, then replace
-      // A with B everywhere in the scope.
-      if ((isKnownTrue && Cmp->getPredicate() == CmpInst::ICMP_EQ) ||
-          (isKnownFalse && Cmp->getPredicate() == CmpInst::ICMP_NE))
-        Worklist.push_back(std::make_pair(Op0, Op1));
-
-      // Handle the floating point versions of equality comparisons too.
-      if ((isKnownTrue && Cmp->getPredicate() == CmpInst::FCMP_OEQ) ||
-          (isKnownFalse && Cmp->getPredicate() == CmpInst::FCMP_UNE)) {
-
-        // Floating point -0.0 and 0.0 compare equal, so we can only
-        // propagate values if we know that we have a constant and that
-        // its value is non-zero.
-
-        // FIXME: We should do this optimization if 'no signed zeros' is
-        // applicable via an instruction-level fast-math-flag or some other
-        // indicator that relaxed FP semantics are being used.
-
-        if (isa<ConstantFP>(Op1) && !cast<ConstantFP>(Op1)->isZero())
-          Worklist.push_back(std::make_pair(Op0, Op1));
-      }
-
-      // If "A >= B" is known true, replace "A < B" with false everywhere.
-      CmpInst::Predicate NotPred = Cmp->getInversePredicate();
-      Constant *NotVal = ConstantInt::get(Cmp->getType(), isKnownFalse);
-      // Since we don't have the instruction "A < B" immediately to hand, work
-      // out the value number that it would have and use that to find an
-      // appropriate instruction (if any).
-      uint32_t NextNum = VN.getNextUnusedValueNumber();
-      uint32_t Num = VN.lookupOrAddCmp(Cmp->getOpcode(), NotPred, Op0, Op1);
-      // If the number we were assigned was brand new then there is no point in
-      // looking for an instruction realizing it: there cannot be one!
-      if (Num < NextNum) {
-        Value *NotCmp = findLeader(Root.getEnd(), Num);
-        if (NotCmp && isa<Instruction>(NotCmp)) {
-          unsigned NumReplacements =
-              DominatesByEdge
-                  ? replaceDominatedUsesWith(NotCmp, NotVal, *DT, Root)
-                  : replaceDominatedUsesWith(NotCmp, NotVal, *DT,
-                                             Root.getStart());
-          Changed |= NumReplacements > 0;
-          NumGVNEqProp += NumReplacements;
-          // Cached information for anything that uses NotCmp will be invalid.
-          if (MD)
-            MD->invalidateCachedPointerInfo(NotCmp);
-        }
-      }
-      // Ensure that any instruction in scope that gets the "A < B" value number
-      // is replaced with false.
-      // The leader table only tracks basic blocks, not edges. Only add to if we
-      // have the simple case where the edge dominates the end.
-      if (RootDominatesEnd)
-        addToLeaderTable(Num, NotVal, Root.getEnd());
-
-      continue;
-    }
-  }
-
-  return Changed;
-}
-
-/// When calculating availability, handle an instruction
-/// by inserting it into the appropriate sets
-bool GVN::processInstruction(Instruction *I) {
-  // Ignore dbg info intrinsics.
-  if (isa<DbgInfoIntrinsic>(I))
-    return false;
-
-  // If the instruction can be easily simplified then do so now in preference
-  // to value numbering it.  Value numbering often exposes redundancies, for
-  // example if it determines that %y is equal to %x then the instruction
-  // "%z = and i32 %x, %y" becomes "%z = and i32 %x, %x" which we now simplify.
-  const DataLayout &DL = I->getModule()->getDataLayout();
-  if (Value *V = SimplifyInstruction(I, {DL, TLI, DT, AC})) {
-    bool Changed = false;
-    if (!I->use_empty()) {
-      I->replaceAllUsesWith(V);
-      Changed = true;
-    }
-    if (isInstructionTriviallyDead(I, TLI)) {
-      markInstructionForDeletion(I);
-      Changed = true;
-    }
-    if (Changed) {
-      if (MD && V->getType()->isPtrOrPtrVectorTy())
-        MD->invalidateCachedPointerInfo(V);
-      ++NumGVNSimpl;
-      return true;
-    }
-  }
-
-  if (IntrinsicInst *IntrinsicI = dyn_cast<IntrinsicInst>(I))
-    if (IntrinsicI->getIntrinsicID() == Intrinsic::assume)
-      return processAssumeIntrinsic(IntrinsicI);
-
-  if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
-    if (processLoad(LI))
-      return true;
-
-    unsigned Num = VN.lookupOrAdd(LI);
-    addToLeaderTable(Num, LI, LI->getParent());
-    return false;
-  }
-
-  // For conditional branches, we can perform simple conditional propagation on
-  // the condition value itself.
-  if (BranchInst *BI = dyn_cast<BranchInst>(I)) {
-    if (!BI->isConditional())
-      return false;
-
-    if (isa<Constant>(BI->getCondition()))
-      return processFoldableCondBr(BI);
-
-    Value *BranchCond = BI->getCondition();
-    BasicBlock *TrueSucc = BI->getSuccessor(0);
-    BasicBlock *FalseSucc = BI->getSuccessor(1);
-    // Avoid multiple edges early.
-    if (TrueSucc == FalseSucc)
-      return false;
-
-    BasicBlock *Parent = BI->getParent();
-    bool Changed = false;
-
-    Value *TrueVal = ConstantInt::getTrue(TrueSucc->getContext());
-    BasicBlockEdge TrueE(Parent, TrueSucc);
-    Changed |= propagateEquality(BranchCond, TrueVal, TrueE, true);
-
-    Value *FalseVal = ConstantInt::getFalse(FalseSucc->getContext());
-    BasicBlockEdge FalseE(Parent, FalseSucc);
-    Changed |= propagateEquality(BranchCond, FalseVal, FalseE, true);
-
-    return Changed;
-  }
-
-  // For switches, propagate the case values into the case destinations.
-  if (SwitchInst *SI = dyn_cast<SwitchInst>(I)) {
-    Value *SwitchCond = SI->getCondition();
-    BasicBlock *Parent = SI->getParent();
-    bool Changed = false;
-
-    // Remember how many outgoing edges there are to every successor.
-    SmallDenseMap<BasicBlock *, unsigned, 16> SwitchEdges;
-    for (unsigned i = 0, n = SI->getNumSuccessors(); i != n; ++i)
-      ++SwitchEdges[SI->getSuccessor(i)];
-
-    for (SwitchInst::CaseIt i = SI->case_begin(), e = SI->case_end();
-         i != e; ++i) {
-      BasicBlock *Dst = i->getCaseSuccessor();
-      // If there is only a single edge, propagate the case value into it.
-      if (SwitchEdges.lookup(Dst) == 1) {
-        BasicBlockEdge E(Parent, Dst);
-        Changed |= propagateEquality(SwitchCond, i->getCaseValue(), E, true);
-      }
-    }
-    return Changed;
-  }
-
-  // Instructions with void type don't return a value, so there's
-  // no point in trying to find redundancies in them.
-  if (I->getType()->isVoidTy())
-    return false;
-
-  uint32_t NextNum = VN.getNextUnusedValueNumber();
-  unsigned Num = VN.lookupOrAdd(I);
-
-  // Allocations are always uniquely numbered, so we can save time and memory
-  // by fast failing them.
-  if (isa<AllocaInst>(I) || I->isTerminator() || isa<PHINode>(I)) {
-    addToLeaderTable(Num, I, I->getParent());
-    return false;
-  }
-
-  // If the number we were assigned was a brand new VN, then we don't
-  // need to do a lookup to see if the number already exists
-  // somewhere in the domtree: it can't!
-  if (Num >= NextNum) {
-    addToLeaderTable(Num, I, I->getParent());
-    return false;
-  }
-
-  // Perform fast-path value-number based elimination of values inherited from
-  // dominators.
-  Value *Repl = findLeader(I->getParent(), Num);
-  if (!Repl) {
-    // Failure, just remember this instance for future use.
-    addToLeaderTable(Num, I, I->getParent());
-    return false;
-  } else if (Repl == I) {
-    // If I was the result of a shortcut PRE, it might already be in the table
-    // and the best replacement for itself. Nothing to do.
-    return false;
-  }
-
-  // Remove it!
-  patchAndReplaceAllUsesWith(I, Repl);
-  if (MD && Repl->getType()->isPtrOrPtrVectorTy())
-    MD->invalidateCachedPointerInfo(Repl);
-  markInstructionForDeletion(I);
-  return true;
-}
-
-/// runOnFunction - This is the main transformation entry point for a function.
-bool GVN::runImpl(Function &F, AssumptionCache &RunAC, DominatorTree &RunDT,
-                  const TargetLibraryInfo &RunTLI, AAResults &RunAA,
-                  MemoryDependenceResults *RunMD, LoopInfo *LI,
-                  OptimizationRemarkEmitter *RunORE) {
-  AC = &RunAC;
-  DT = &RunDT;
-  VN.setDomTree(DT);
-  TLI = &RunTLI;
-  VN.setAliasAnalysis(&RunAA);
-  MD = RunMD;
-  ImplicitControlFlowTracking ImplicitCFT(DT);
-  ICF = &ImplicitCFT;
-  VN.setMemDep(MD);
-  ORE = RunORE;
-  InvalidBlockRPONumbers = true;
-
-  bool Changed = false;
-  bool ShouldContinue = true;
-
-  DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Eager);
-  // Merge unconditional branches, allowing PRE to catch more
-  // optimization opportunities.
-  for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ) {
-    BasicBlock *BB = &*FI++;
-
-    bool removedBlock = MergeBlockIntoPredecessor(BB, &DTU, LI, nullptr, MD);
-    if (removedBlock)
-      ++NumGVNBlocks;
-
-    Changed |= removedBlock;
-  }
-
-  unsigned Iteration = 0;
-  while (ShouldContinue) {
-    LLVM_DEBUG(dbgs() << "GVN iteration: " << Iteration << "\n");
-    ShouldContinue = iterateOnFunction(F);
-    Changed |= ShouldContinue;
-    ++Iteration;
-  }
-
-  if (EnablePRE) {
-    // Fabricate val-num for dead-code in order to suppress assertion in
-    // performPRE().
-    assignValNumForDeadCode();
-    bool PREChanged = true;
-    while (PREChanged) {
-      PREChanged = performPRE(F);
-      Changed |= PREChanged;
-    }
-  }
-
-  // FIXME: Should perform GVN again after PRE does something.  PRE can move
-  // computations into blocks where they become fully redundant.  Note that
-  // we can't do this until PRE's critical edge splitting updates memdep.
-  // Actually, when this happens, we should just fully integrate PRE into GVN.
-
-  cleanupGlobalSets();
-  // Do not cleanup DeadBlocks in cleanupGlobalSets() as it's called for each
-  // iteration.
-  DeadBlocks.clear();
-
-  return Changed;
-}
-
-bool GVN::processBlock(BasicBlock *BB) {
-  // FIXME: Kill off InstrsToErase by doing erasing eagerly in a helper function
-  // (and incrementing BI before processing an instruction).
-  assert(InstrsToErase.empty() &&
-         "We expect InstrsToErase to be empty across iterations");
-  if (DeadBlocks.count(BB))
-    return false;
-
-  // Clearing map before every BB because it can be used only for single BB.
-  ReplaceWithConstMap.clear();
-  bool ChangedFunction = false;
-
-  for (BasicBlock::iterator BI = BB->begin(), BE = BB->end();
-       BI != BE;) {
-    if (!ReplaceWithConstMap.empty())
-      ChangedFunction |= replaceOperandsWithConsts(&*BI);
-    ChangedFunction |= processInstruction(&*BI);
-
-    if (InstrsToErase.empty()) {
-      ++BI;
-      continue;
-    }
-
-    // If we need some instructions deleted, do it now.
-    NumGVNInstr += InstrsToErase.size();
-
-    // Avoid iterator invalidation.
-    bool AtStart = BI == BB->begin();
-    if (!AtStart)
-      --BI;
-
-    for (auto *I : InstrsToErase) {
-      assert(I->getParent() == BB && "Removing instruction from wrong block?");
-      LLVM_DEBUG(dbgs() << "GVN removed: " << *I << '\n');
-      salvageDebugInfo(*I);
-      if (MD) MD->removeInstruction(I);
-      LLVM_DEBUG(verifyRemoved(I));
-      ICF->removeInstruction(I);
-      I->eraseFromParent();
-    }
-    InstrsToErase.clear();
-
-    if (AtStart)
-      BI = BB->begin();
-    else
-      ++BI;
-  }
-
-  return ChangedFunction;
-}
-
-// Instantiate an expression in a predecessor that lacked it.
-bool GVN::performScalarPREInsertion(Instruction *Instr, BasicBlock *Pred,
-                                    BasicBlock *Curr, unsigned int ValNo) {
-  // Because we are going top-down through the block, all value numbers
-  // will be available in the predecessor by the time we need them.  Any
-  // that weren't originally present will have been instantiated earlier
-  // in this loop.
-  bool success = true;
-  for (unsigned i = 0, e = Instr->getNumOperands(); i != e; ++i) {
-    Value *Op = Instr->getOperand(i);
-    if (isa<Argument>(Op) || isa<Constant>(Op) || isa<GlobalValue>(Op))
-      continue;
-    // This could be a newly inserted instruction, in which case, we won't
-    // find a value number, and should give up before we hurt ourselves.
-    // FIXME: Rewrite the infrastructure to let it easier to value number
-    // and process newly inserted instructions.
-    if (!VN.exists(Op)) {
-      success = false;
-      break;
-    }
-    uint32_t TValNo =
-        VN.phiTranslate(Pred, Curr, VN.lookup(Op), *this);
-    if (Value *V = findLeader(Pred, TValNo)) {
-      Instr->setOperand(i, V);
-    } else {
-      success = false;
-      break;
-    }
-  }
-
-  // Fail out if we encounter an operand that is not available in
-  // the PRE predecessor.  This is typically because of loads which
-  // are not value numbered precisely.
-  if (!success)
-    return false;
-
-  Instr->insertBefore(Pred->getTerminator());
-  Instr->setName(Instr->getName() + ".pre");
-  Instr->setDebugLoc(Instr->getDebugLoc());
-
-  unsigned Num = VN.lookupOrAdd(Instr);
-  VN.add(Instr, Num);
-
-  // Update the availability map to include the new instruction.
-  addToLeaderTable(Num, Instr, Pred);
-  return true;
-}
-
-bool GVN::performScalarPRE(Instruction *CurInst) {
-  if (isa<AllocaInst>(CurInst) || CurInst->isTerminator() ||
-      isa<PHINode>(CurInst) || CurInst->getType()->isVoidTy() ||
-      CurInst->mayReadFromMemory() || CurInst->mayHaveSideEffects() ||
-      isa<DbgInfoIntrinsic>(CurInst))
-    return false;
-
-  // Don't do PRE on compares. The PHI would prevent CodeGenPrepare from
-  // sinking the compare again, and it would force the code generator to
-  // move the i1 from processor flags or predicate registers into a general
-  // purpose register.
-  if (isa<CmpInst>(CurInst))
-    return false;
-
-  // Don't do PRE on GEPs. The inserted PHI would prevent CodeGenPrepare from
-  // sinking the addressing mode computation back to its uses. Extending the
-  // GEP's live range increases the register pressure, and therefore it can
-  // introduce unnecessary spills.
-  //
-  // This doesn't prevent Load PRE. PHI translation will make the GEP available
-  // to the load by moving it to the predecessor block if necessary.
-  if (isa<GetElementPtrInst>(CurInst))
-    return false;
-
-  // We don't currently value number ANY inline asm calls.
-  if (CallInst *CallI = dyn_cast<CallInst>(CurInst))
-    if (CallI->isInlineAsm())
-      return false;
-
-  uint32_t ValNo = VN.lookup(CurInst);
-
-  // Look for the predecessors for PRE opportunities.  We're
-  // only trying to solve the basic diamond case, where
-  // a value is computed in the successor and one predecessor,
-  // but not the other.  We also explicitly disallow cases
-  // where the successor is its own predecessor, because they're
-  // more complicated to get right.
-  unsigned NumWith = 0;
-  unsigned NumWithout = 0;
-  BasicBlock *PREPred = nullptr;
-  BasicBlock *CurrentBlock = CurInst->getParent();
-
-  // Update the RPO numbers for this function.
-  if (InvalidBlockRPONumbers)
-    assignBlockRPONumber(*CurrentBlock->getParent());
-
-  SmallVector<std::pair<Value *, BasicBlock *>, 8> predMap;
-  for (BasicBlock *P : predecessors(CurrentBlock)) {
-    // We're not interested in PRE where blocks with predecessors that are
-    // not reachable.
-    if (!DT->isReachableFromEntry(P)) {
-      NumWithout = 2;
-      break;
-    }
-    // It is not safe to do PRE when P->CurrentBlock is a loop backedge, and
-    // when CurInst has operand defined in CurrentBlock (so it may be defined
-    // by phi in the loop header).
-    assert(BlockRPONumber.count(P) && BlockRPONumber.count(CurrentBlock) &&
-           "Invalid BlockRPONumber map.");
-    if (BlockRPONumber[P] >= BlockRPONumber[CurrentBlock] &&
-        llvm::any_of(CurInst->operands(), [&](const Use &U) {
-          if (auto *Inst = dyn_cast<Instruction>(U.get()))
-            return Inst->getParent() == CurrentBlock;
-          return false;
-        })) {
-      NumWithout = 2;
-      break;
-    }
-
-    uint32_t TValNo = VN.phiTranslate(P, CurrentBlock, ValNo, *this);
-    Value *predV = findLeader(P, TValNo);
-    if (!predV) {
-      predMap.push_back(std::make_pair(static_cast<Value *>(nullptr), P));
-      PREPred = P;
-      ++NumWithout;
-    } else if (predV == CurInst) {
-      /* CurInst dominates this predecessor. */
-      NumWithout = 2;
-      break;
-    } else {
-      predMap.push_back(std::make_pair(predV, P));
-      ++NumWith;
-    }
-  }
-
-  // Don't do PRE when it might increase code size, i.e. when
-  // we would need to insert instructions in more than one pred.
-  if (NumWithout > 1 || NumWith == 0)
-    return false;
-
-  // We may have a case where all predecessors have the instruction,
-  // and we just need to insert a phi node. Otherwise, perform
-  // insertion.
-  Instruction *PREInstr = nullptr;
-
-  if (NumWithout != 0) {
-    if (!isSafeToSpeculativelyExecute(CurInst)) {
-      // It is only valid to insert a new instruction if the current instruction
-      // is always executed. An instruction with implicit control flow could
-      // prevent us from doing it. If we cannot speculate the execution, then
-      // PRE should be prohibited.
-      if (ICF->isDominatedByICFIFromSameBlock(CurInst))
-        return false;
-    }
-
-    // Don't do PRE across indirect branch.
-    if (isa<IndirectBrInst>(PREPred->getTerminator()))
-      return false;
-
-    // We can't do PRE safely on a critical edge, so instead we schedule
-    // the edge to be split and perform the PRE the next time we iterate
-    // on the function.
-    unsigned SuccNum = GetSuccessorNumber(PREPred, CurrentBlock);
-    if (isCriticalEdge(PREPred->getTerminator(), SuccNum)) {
-      toSplit.push_back(std::make_pair(PREPred->getTerminator(), SuccNum));
-      return false;
-    }
-    // We need to insert somewhere, so let's give it a shot
-    PREInstr = CurInst->clone();
-    if (!performScalarPREInsertion(PREInstr, PREPred, CurrentBlock, ValNo)) {
-      // If we failed insertion, make sure we remove the instruction.
-      LLVM_DEBUG(verifyRemoved(PREInstr));
-      PREInstr->deleteValue();
-      return false;
-    }
-  }
-
-  // Either we should have filled in the PRE instruction, or we should
-  // not have needed insertions.
-  assert(PREInstr != nullptr || NumWithout == 0);
-
-  ++NumGVNPRE;
-
-  // Create a PHI to make the value available in this block.
-  PHINode *Phi =
-      PHINode::Create(CurInst->getType(), predMap.size(),
-                      CurInst->getName() + ".pre-phi", &CurrentBlock->front());
-  for (unsigned i = 0, e = predMap.size(); i != e; ++i) {
-    if (Value *V = predMap[i].first) {
-      // If we use an existing value in this phi, we have to patch the original
-      // value because the phi will be used to replace a later value.
-      patchReplacementInstruction(CurInst, V);
-      Phi->addIncoming(V, predMap[i].second);
-    } else
-      Phi->addIncoming(PREInstr, PREPred);
-  }
-
-  VN.add(Phi, ValNo);
-  // After creating a new PHI for ValNo, the phi translate result for ValNo will
-  // be changed, so erase the related stale entries in phi translate cache.
-  VN.eraseTranslateCacheEntry(ValNo, *CurrentBlock);
-  addToLeaderTable(ValNo, Phi, CurrentBlock);
-  Phi->setDebugLoc(CurInst->getDebugLoc());
-  CurInst->replaceAllUsesWith(Phi);
-  if (MD && Phi->getType()->isPtrOrPtrVectorTy())
-    MD->invalidateCachedPointerInfo(Phi);
-  VN.erase(CurInst);
-  removeFromLeaderTable(ValNo, CurInst, CurrentBlock);
-
-  LLVM_DEBUG(dbgs() << "GVN PRE removed: " << *CurInst << '\n');
-  if (MD)
-    MD->removeInstruction(CurInst);
-  LLVM_DEBUG(verifyRemoved(CurInst));
-  // FIXME: Intended to be markInstructionForDeletion(CurInst), but it causes
-  // some assertion failures.
-  ICF->removeInstruction(CurInst);
-  CurInst->eraseFromParent();
-  ++NumGVNInstr;
-
-  return true;
-}
-
-/// Perform a purely local form of PRE that looks for diamond
-/// control flow patterns and attempts to perform simple PRE at the join point.
-bool GVN::performPRE(Function &F) {
-  bool Changed = false;
-  for (BasicBlock *CurrentBlock : depth_first(&F.getEntryBlock())) {
-    // Nothing to PRE in the entry block.
-    if (CurrentBlock == &F.getEntryBlock())
-      continue;
-
-    // Don't perform PRE on an EH pad.
-    if (CurrentBlock->isEHPad())
-      continue;
-
-    for (BasicBlock::iterator BI = CurrentBlock->begin(),
-                              BE = CurrentBlock->end();
-         BI != BE;) {
-      Instruction *CurInst = &*BI++;
-      Changed |= performScalarPRE(CurInst);
-    }
-  }
-
-  if (splitCriticalEdges())
-    Changed = true;
-
-  return Changed;
-}
-
-/// Split the critical edge connecting the given two blocks, and return
-/// the block inserted to the critical edge.
-BasicBlock *GVN::splitCriticalEdges(BasicBlock *Pred, BasicBlock *Succ) {
-  BasicBlock *BB =
-      SplitCriticalEdge(Pred, Succ, CriticalEdgeSplittingOptions(DT));
-  if (MD)
-    MD->invalidateCachedPredecessors();
-  InvalidBlockRPONumbers = true;
-  return BB;
-}
-
-/// Split critical edges found during the previous
-/// iteration that may enable further optimization.
-bool GVN::splitCriticalEdges() {
-  if (toSplit.empty())
-    return false;
-  do {
-    std::pair<Instruction *, unsigned> Edge = toSplit.pop_back_val();
-    SplitCriticalEdge(Edge.first, Edge.second,
-                      CriticalEdgeSplittingOptions(DT));
-  } while (!toSplit.empty());
-  if (MD) MD->invalidateCachedPredecessors();
-  InvalidBlockRPONumbers = true;
-  return true;
-}
-
-/// Executes one iteration of GVN
-bool GVN::iterateOnFunction(Function &F) {
-  cleanupGlobalSets();
-
-  // Top-down walk of the dominator tree
-  bool Changed = false;
-  // Needed for value numbering with phi construction to work.
-  // RPOT walks the graph in its constructor and will not be invalidated during
-  // processBlock.
-  ReversePostOrderTraversal<Function *> RPOT(&F);
-
-  for (BasicBlock *BB : RPOT)
-    Changed |= processBlock(BB);
-
-  return Changed;
-}
-
-void GVN::cleanupGlobalSets() {
-  VN.clear();
-  LeaderTable.clear();
-  BlockRPONumber.clear();
-  TableAllocator.Reset();
-  ICF->clear();
-  InvalidBlockRPONumbers = true;
-}
-
-/// Verify that the specified instruction does not occur in our
-/// internal data structures.
-void GVN::verifyRemoved(const Instruction *Inst) const {
-  VN.verifyRemoved(Inst);
-
-  // Walk through the value number scope to make sure the instruction isn't
-  // ferreted away in it.
-  for (DenseMap<uint32_t, LeaderTableEntry>::const_iterator
-       I = LeaderTable.begin(), E = LeaderTable.end(); I != E; ++I) {
-    const LeaderTableEntry *Node = &I->second;
-    assert(Node->Val != Inst && "Inst still in value numbering scope!");
-
-    while (Node->Next) {
-      Node = Node->Next;
-      assert(Node->Val != Inst && "Inst still in value numbering scope!");
-    }
-  }
-}
-
-/// BB is declared dead, which implied other blocks become dead as well. This
-/// function is to add all these blocks to "DeadBlocks". For the dead blocks'
-/// live successors, update their phi nodes by replacing the operands
-/// corresponding to dead blocks with UndefVal.
-void GVN::addDeadBlock(BasicBlock *BB) {
-  SmallVector<BasicBlock *, 4> NewDead;
-  SmallSetVector<BasicBlock *, 4> DF;
-
-  NewDead.push_back(BB);
-  while (!NewDead.empty()) {
-    BasicBlock *D = NewDead.pop_back_val();
-    if (DeadBlocks.count(D))
-      continue;
-
-    // All blocks dominated by D are dead.
-    SmallVector<BasicBlock *, 8> Dom;
-    DT->getDescendants(D, Dom);
-    DeadBlocks.insert(Dom.begin(), Dom.end());
-
-    // Figure out the dominance-frontier(D).
-    for (BasicBlock *B : Dom) {
-      for (BasicBlock *S : successors(B)) {
-        if (DeadBlocks.count(S))
-          continue;
-
-        bool AllPredDead = true;
-        for (BasicBlock *P : predecessors(S))
-          if (!DeadBlocks.count(P)) {
-            AllPredDead = false;
-            break;
-          }
-
-        if (!AllPredDead) {
-          // S could be proved dead later on. That is why we don't update phi
-          // operands at this moment.
-          DF.insert(S);
-        } else {
-          // While S is not dominated by D, it is dead by now. This could take
-          // place if S already have a dead predecessor before D is declared
-          // dead.
-          NewDead.push_back(S);
-        }
-      }
-    }
-  }
-
-  // For the dead blocks' live successors, update their phi nodes by replacing
-  // the operands corresponding to dead blocks with UndefVal.
-  for(SmallSetVector<BasicBlock *, 4>::iterator I = DF.begin(), E = DF.end();
-        I != E; I++) {
-    BasicBlock *B = *I;
-    if (DeadBlocks.count(B))
-      continue;
-
-    SmallVector<BasicBlock *, 4> Preds(pred_begin(B), pred_end(B));
-    for (BasicBlock *P : Preds) {
-      if (!DeadBlocks.count(P))
-        continue;
-
-      if (isCriticalEdge(P->getTerminator(), GetSuccessorNumber(P, B))) {
-        if (BasicBlock *S = splitCriticalEdges(P, B))
-          DeadBlocks.insert(P = S);
-      }
-
-      for (BasicBlock::iterator II = B->begin(); isa<PHINode>(II); ++II) {
-        PHINode &Phi = cast<PHINode>(*II);
-        Phi.setIncomingValue(Phi.getBasicBlockIndex(P),
-                             UndefValue::get(Phi.getType()));
-        if (MD)
-          MD->invalidateCachedPointerInfo(&Phi);
-      }
-    }
-  }
-}
-
-// If the given branch is recognized as a foldable branch (i.e. conditional
-// branch with constant condition), it will perform following analyses and
-// transformation.
-//  1) If the dead out-coming edge is a critical-edge, split it. Let
-//     R be the target of the dead out-coming edge.
-//  1) Identify the set of dead blocks implied by the branch's dead outcoming
-//     edge. The result of this step will be {X| X is dominated by R}
-//  2) Identify those blocks which haves at least one dead predecessor. The
-//     result of this step will be dominance-frontier(R).
-//  3) Update the PHIs in DF(R) by replacing the operands corresponding to
-//     dead blocks with "UndefVal" in an hope these PHIs will optimized away.
-//
-// Return true iff *NEW* dead code are found.
-bool GVN::processFoldableCondBr(BranchInst *BI) {
-  if (!BI || BI->isUnconditional())
-    return false;
-
-  // If a branch has two identical successors, we cannot declare either dead.
-  if (BI->getSuccessor(0) == BI->getSuccessor(1))
-    return false;
-
-  ConstantInt *Cond = dyn_cast<ConstantInt>(BI->getCondition());
-  if (!Cond)
-    return false;
-
-  BasicBlock *DeadRoot =
-      Cond->getZExtValue() ? BI->getSuccessor(1) : BI->getSuccessor(0);
-  if (DeadBlocks.count(DeadRoot))
-    return false;
-
-  if (!DeadRoot->getSinglePredecessor())
-    DeadRoot = splitCriticalEdges(BI->getParent(), DeadRoot);
-
-  addDeadBlock(DeadRoot);
-  return true;
-}
-
-// performPRE() will trigger assert if it comes across an instruction without
-// associated val-num. As it normally has far more live instructions than dead
-// instructions, it makes more sense just to "fabricate" a val-number for the
-// dead code than checking if instruction involved is dead or not.
-void GVN::assignValNumForDeadCode() {
-  for (BasicBlock *BB : DeadBlocks) {
-    for (Instruction &Inst : *BB) {
-      unsigned ValNum = VN.lookupOrAdd(&Inst);
-      addToLeaderTable(ValNum, &Inst, BB);
-    }
-  }
-}
-
-class llvm::gvn::GVNLegacyPass : public FunctionPass {
-public:
-  static char ID; // Pass identification, replacement for typeid
-
-  explicit GVNLegacyPass(bool NoMemDepAnalysis = !EnableMemDep)
-      : FunctionPass(ID), NoMemDepAnalysis(NoMemDepAnalysis) {
-    initializeGVNLegacyPassPass(*PassRegistry::getPassRegistry());
-  }
-
-  bool runOnFunction(Function &F) override {
-    if (skipFunction(F))
-      return false;
-
-    auto *LIWP = getAnalysisIfAvailable<LoopInfoWrapperPass>();
-
-    return Impl.runImpl(
-        F, getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F),
-        getAnalysis<DominatorTreeWrapperPass>().getDomTree(),
-        getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(),
-        getAnalysis<AAResultsWrapperPass>().getAAResults(),
-        NoMemDepAnalysis ? nullptr
-                : &getAnalysis<MemoryDependenceWrapperPass>().getMemDep(),
-        LIWP ? &LIWP->getLoopInfo() : nullptr,
-        &getAnalysis<OptimizationRemarkEmitterWrapperPass>().getORE());
-  }
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.addRequired<AssumptionCacheTracker>();
-    AU.addRequired<DominatorTreeWrapperPass>();
-    AU.addRequired<TargetLibraryInfoWrapperPass>();
-    if (!NoMemDepAnalysis)
-      AU.addRequired<MemoryDependenceWrapperPass>();
-    AU.addRequired<AAResultsWrapperPass>();
-
-    AU.addPreserved<DominatorTreeWrapperPass>();
-    AU.addPreserved<GlobalsAAWrapperPass>();
-    AU.addPreserved<TargetLibraryInfoWrapperPass>();
-    AU.addRequired<OptimizationRemarkEmitterWrapperPass>();
-  }
-
-private:
-  bool NoMemDepAnalysis;
-  GVN Impl;
-};
-
-char GVNLegacyPass::ID = 0;
-
-INITIALIZE_PASS_BEGIN(GVNLegacyPass, "gvn", "Global Value Numbering", false, false)
-INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
-INITIALIZE_PASS_DEPENDENCY(MemoryDependenceWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(GlobalsAAWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(OptimizationRemarkEmitterWrapperPass)
-INITIALIZE_PASS_END(GVNLegacyPass, "gvn", "Global Value Numbering", false, false)
-
-// The public interface to this file...
-FunctionPass *llvm::createGVNPass(bool NoMemDepAnalysis) {
-  return new GVNLegacyPass(NoMemDepAnalysis);
-}