1 files changed, 0 insertions, 1041 deletions

diff --git a/contrib/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp b/contrib/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
deleted file mode 100644
index f59c906c7b75..000000000000
--- a/contrib/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
+++ /dev/null
@@ -1,1041 +0,0 @@
-//===- ValueEnumerator.cpp - Number values and types for bitcode writer ---===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the ValueEnumerator class.
-//
-//===----------------------------------------------------------------------===//
-
-#include "ValueEnumerator.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/Config/llvm-config.h"
-#include "llvm/IR/Argument.h"
-#include "llvm/IR/Attributes.h"
-#include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/Constant.h"
-#include "llvm/IR/DebugInfoMetadata.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/GlobalAlias.h"
-#include "llvm/IR/GlobalIFunc.h"
-#include "llvm/IR/GlobalObject.h"
-#include "llvm/IR/GlobalValue.h"
-#include "llvm/IR/GlobalVariable.h"
-#include "llvm/IR/Instruction.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/Metadata.h"
-#include "llvm/IR/Module.h"
-#include "llvm/IR/Type.h"
-#include "llvm/IR/Use.h"
-#include "llvm/IR/UseListOrder.h"
-#include "llvm/IR/User.h"
-#include "llvm/IR/Value.h"
-#include "llvm/IR/ValueSymbolTable.h"
-#include "llvm/Support/Casting.h"
-#include "llvm/Support/Compiler.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/MathExtras.h"
-#include "llvm/Support/raw_ostream.h"
-#include <algorithm>
-#include <cassert>
-#include <cstddef>
-#include <iterator>
-#include <tuple>
-#include <utility>
-#include <vector>
-
-using namespace llvm;
-
-namespace {
-
-struct OrderMap {
-  DenseMap<const Value *, std::pair<unsigned, bool>> IDs;
-  unsigned LastGlobalConstantID = 0;
-  unsigned LastGlobalValueID = 0;
-
-  OrderMap() = default;
-
-  bool isGlobalConstant(unsigned ID) const {
-    return ID <= LastGlobalConstantID;
-  }
-
-  bool isGlobalValue(unsigned ID) const {
-    return ID <= LastGlobalValueID && !isGlobalConstant(ID);
-  }
-
-  unsigned size() const { return IDs.size(); }
-  std::pair<unsigned, bool> &operator[](const Value *V) { return IDs[V]; }
-
-  std::pair<unsigned, bool> lookup(const Value *V) const {
-    return IDs.lookup(V);
-  }
-
-  void index(const Value *V) {
-    // Explicitly sequence get-size and insert-value operations to avoid UB.
-    unsigned ID = IDs.size() + 1;
-    IDs[V].first = ID;
-  }
-};
-
-} // end anonymous namespace
-
-static void orderValue(const Value *V, OrderMap &OM) {
-  if (OM.lookup(V).first)
-    return;
-
-  if (const Constant *C = dyn_cast<Constant>(V))
-    if (C->getNumOperands() && !isa<GlobalValue>(C))
-      for (const Value *Op : C->operands())
-        if (!isa<BasicBlock>(Op) && !isa<GlobalValue>(Op))
-          orderValue(Op, OM);
-
-  // Note: we cannot cache this lookup above, since inserting into the map
-  // changes the map's size, and thus affects the other IDs.
-  OM.index(V);
-}
-
-static OrderMap orderModule(const Module &M) {
-  // This needs to match the order used by ValueEnumerator::ValueEnumerator()
-  // and ValueEnumerator::incorporateFunction().
-  OrderMap OM;
-
-  // In the reader, initializers of GlobalValues are set *after* all the
-  // globals have been read.  Rather than awkwardly modeling this behaviour
-  // directly in predictValueUseListOrderImpl(), just assign IDs to
-  // initializers of GlobalValues before GlobalValues themselves to model this
-  // implicitly.
-  for (const GlobalVariable &G : M.globals())
-    if (G.hasInitializer())
-      if (!isa<GlobalValue>(G.getInitializer()))
-        orderValue(G.getInitializer(), OM);
-  for (const GlobalAlias &A : M.aliases())
-    if (!isa<GlobalValue>(A.getAliasee()))
-      orderValue(A.getAliasee(), OM);
-  for (const GlobalIFunc &I : M.ifuncs())
-    if (!isa<GlobalValue>(I.getResolver()))
-      orderValue(I.getResolver(), OM);
-  for (const Function &F : M) {
-    for (const Use &U : F.operands())
-      if (!isa<GlobalValue>(U.get()))
-        orderValue(U.get(), OM);
-  }
-  OM.LastGlobalConstantID = OM.size();
-
-  // Initializers of GlobalValues are processed in
-  // BitcodeReader::ResolveGlobalAndAliasInits().  Match the order there rather
-  // than ValueEnumerator, and match the code in predictValueUseListOrderImpl()
-  // by giving IDs in reverse order.
-  //
-  // Since GlobalValues never reference each other directly (just through
-  // initializers), their relative IDs only matter for determining order of
-  // uses in their initializers.
-  for (const Function &F : M)
-    orderValue(&F, OM);
-  for (const GlobalAlias &A : M.aliases())
-    orderValue(&A, OM);
-  for (const GlobalIFunc &I : M.ifuncs())
-    orderValue(&I, OM);
-  for (const GlobalVariable &G : M.globals())
-    orderValue(&G, OM);
-  OM.LastGlobalValueID = OM.size();
-
-  for (const Function &F : M) {
-    if (F.isDeclaration())
-      continue;
-    // Here we need to match the union of ValueEnumerator::incorporateFunction()
-    // and WriteFunction().  Basic blocks are implicitly declared before
-    // anything else (by declaring their size).
-    for (const BasicBlock &BB : F)
-      orderValue(&BB, OM);
-    for (const Argument &A : F.args())
-      orderValue(&A, OM);
-    for (const BasicBlock &BB : F)
-      for (const Instruction &I : BB)
-        for (const Value *Op : I.operands())
-          if ((isa<Constant>(*Op) && !isa<GlobalValue>(*Op)) ||
-              isa<InlineAsm>(*Op))
-            orderValue(Op, OM);
-    for (const BasicBlock &BB : F)
-      for (const Instruction &I : BB)
-        orderValue(&I, OM);
-  }
-  return OM;
-}
-
-static void predictValueUseListOrderImpl(const Value *V, const Function *F,
-                                         unsigned ID, const OrderMap &OM,
-                                         UseListOrderStack &Stack) {
-  // Predict use-list order for this one.
-  using Entry = std::pair<const Use *, unsigned>;
-  SmallVector<Entry, 64> List;
-  for (const Use &U : V->uses())
-    // Check if this user will be serialized.
-    if (OM.lookup(U.getUser()).first)
-      List.push_back(std::make_pair(&U, List.size()));
-
-  if (List.size() < 2)
-    // We may have lost some users.
-    return;
-
-  bool IsGlobalValue = OM.isGlobalValue(ID);
-  llvm::sort(List, [&](const Entry &L, const Entry &R) {
-    const Use *LU = L.first;
-    const Use *RU = R.first;
-    if (LU == RU)
-      return false;
-
-    auto LID = OM.lookup(LU->getUser()).first;
-    auto RID = OM.lookup(RU->getUser()).first;
-
-    // Global values are processed in reverse order.
-    //
-    // Moreover, initializers of GlobalValues are set *after* all the globals
-    // have been read (despite having earlier IDs).  Rather than awkwardly
-    // modeling this behaviour here, orderModule() has assigned IDs to
-    // initializers of GlobalValues before GlobalValues themselves.
-    if (OM.isGlobalValue(LID) && OM.isGlobalValue(RID))
-      return LID < RID;
-
-    // If ID is 4, then expect: 7 6 5 1 2 3.
-    if (LID < RID) {
-      if (RID <= ID)
-        if (!IsGlobalValue) // GlobalValue uses don't get reversed.
-          return true;
-      return false;
-    }
-    if (RID < LID) {
-      if (LID <= ID)
-        if (!IsGlobalValue) // GlobalValue uses don't get reversed.
-          return false;
-      return true;
-    }
-
-    // LID and RID are equal, so we have different operands of the same user.
-    // Assume operands are added in order for all instructions.
-    if (LID <= ID)
-      if (!IsGlobalValue) // GlobalValue uses don't get reversed.
-        return LU->getOperandNo() < RU->getOperandNo();
-    return LU->getOperandNo() > RU->getOperandNo();
-  });
-
-  if (std::is_sorted(
-          List.begin(), List.end(),
-          [](const Entry &L, const Entry &R) { return L.second < R.second; }))
-    // Order is already correct.
-    return;
-
-  // Store the shuffle.
-  Stack.emplace_back(V, F, List.size());
-  assert(List.size() == Stack.back().Shuffle.size() && "Wrong size");
-  for (size_t I = 0, E = List.size(); I != E; ++I)
-    Stack.back().Shuffle[I] = List[I].second;
-}
-
-static void predictValueUseListOrder(const Value *V, const Function *F,
-                                     OrderMap &OM, UseListOrderStack &Stack) {
-  auto &IDPair = OM[V];
-  assert(IDPair.first && "Unmapped value");
-  if (IDPair.second)
-    // Already predicted.
-    return;
-
-  // Do the actual prediction.
-  IDPair.second = true;
-  if (!V->use_empty() && std::next(V->use_begin()) != V->use_end())
-    predictValueUseListOrderImpl(V, F, IDPair.first, OM, Stack);
-
-  // Recursive descent into constants.
-  if (const Constant *C = dyn_cast<Constant>(V))
-    if (C->getNumOperands()) // Visit GlobalValues.
-      for (const Value *Op : C->operands())
-        if (isa<Constant>(Op)) // Visit GlobalValues.
-          predictValueUseListOrder(Op, F, OM, Stack);
-}
-
-static UseListOrderStack predictUseListOrder(const Module &M) {
-  OrderMap OM = orderModule(M);
-
-  // Use-list orders need to be serialized after all the users have been added
-  // to a value, or else the shuffles will be incomplete.  Store them per
-  // function in a stack.
-  //
-  // Aside from function order, the order of values doesn't matter much here.
-  UseListOrderStack Stack;
-
-  // We want to visit the functions backward now so we can list function-local
-  // constants in the last Function they're used in.  Module-level constants
-  // have already been visited above.
-  for (auto I = M.rbegin(), E = M.rend(); I != E; ++I) {
-    const Function &F = *I;
-    if (F.isDeclaration())
-      continue;
-    for (const BasicBlock &BB : F)
-      predictValueUseListOrder(&BB, &F, OM, Stack);
-    for (const Argument &A : F.args())
-      predictValueUseListOrder(&A, &F, OM, Stack);
-    for (const BasicBlock &BB : F)
-      for (const Instruction &I : BB)
-        for (const Value *Op : I.operands())
-          if (isa<Constant>(*Op) || isa<InlineAsm>(*Op)) // Visit GlobalValues.
-            predictValueUseListOrder(Op, &F, OM, Stack);
-    for (const BasicBlock &BB : F)
-      for (const Instruction &I : BB)
-        predictValueUseListOrder(&I, &F, OM, Stack);
-  }
-
-  // Visit globals last, since the module-level use-list block will be seen
-  // before the function bodies are processed.
-  for (const GlobalVariable &G : M.globals())
-    predictValueUseListOrder(&G, nullptr, OM, Stack);
-  for (const Function &F : M)
-    predictValueUseListOrder(&F, nullptr, OM, Stack);
-  for (const GlobalAlias &A : M.aliases())
-    predictValueUseListOrder(&A, nullptr, OM, Stack);
-  for (const GlobalIFunc &I : M.ifuncs())
-    predictValueUseListOrder(&I, nullptr, OM, Stack);
-  for (const GlobalVariable &G : M.globals())
-    if (G.hasInitializer())
-      predictValueUseListOrder(G.getInitializer(), nullptr, OM, Stack);
-  for (const GlobalAlias &A : M.aliases())
-    predictValueUseListOrder(A.getAliasee(), nullptr, OM, Stack);
-  for (const GlobalIFunc &I : M.ifuncs())
-    predictValueUseListOrder(I.getResolver(), nullptr, OM, Stack);
-  for (const Function &F : M) {
-    for (const Use &U : F.operands())
-      predictValueUseListOrder(U.get(), nullptr, OM, Stack);
-  }
-
-  return Stack;
-}
-
-static bool isIntOrIntVectorValue(const std::pair<const Value*, unsigned> &V) {
-  return V.first->getType()->isIntOrIntVectorTy();
-}
-
-ValueEnumerator::ValueEnumerator(const Module &M,
-                                 bool ShouldPreserveUseListOrder)
-    : ShouldPreserveUseListOrder(ShouldPreserveUseListOrder) {
-  if (ShouldPreserveUseListOrder)
-    UseListOrders = predictUseListOrder(M);
-
-  // Enumerate the global variables.
-  for (const GlobalVariable &GV : M.globals())
-    EnumerateValue(&GV);
-
-  // Enumerate the functions.
-  for (const Function & F : M) {
-    EnumerateValue(&F);
-    EnumerateAttributes(F.getAttributes());
-  }
-
-  // Enumerate the aliases.
-  for (const GlobalAlias &GA : M.aliases())
-    EnumerateValue(&GA);
-
-  // Enumerate the ifuncs.
-  for (const GlobalIFunc &GIF : M.ifuncs())
-    EnumerateValue(&GIF);
-
-  // Remember what is the cutoff between globalvalue's and other constants.
-  unsigned FirstConstant = Values.size();
-
-  // Enumerate the global variable initializers and attributes.
-  for (const GlobalVariable &GV : M.globals()) {
-    if (GV.hasInitializer())
-      EnumerateValue(GV.getInitializer());
-    if (GV.hasAttributes())
-      EnumerateAttributes(GV.getAttributesAsList(AttributeList::FunctionIndex));
-  }
-
-  // Enumerate the aliasees.
-  for (const GlobalAlias &GA : M.aliases())
-    EnumerateValue(GA.getAliasee());
-
-  // Enumerate the ifunc resolvers.
-  for (const GlobalIFunc &GIF : M.ifuncs())
-    EnumerateValue(GIF.getResolver());
-
-  // Enumerate any optional Function data.
-  for (const Function &F : M)
-    for (const Use &U : F.operands())
-      EnumerateValue(U.get());
-
-  // Enumerate the metadata type.
-  //
-  // TODO: Move this to ValueEnumerator::EnumerateOperandType() once bitcode
-  // only encodes the metadata type when it's used as a value.
-  EnumerateType(Type::getMetadataTy(M.getContext()));
-
-  // Insert constants and metadata that are named at module level into the slot
-  // pool so that the module symbol table can refer to them...
-  EnumerateValueSymbolTable(M.getValueSymbolTable());
-  EnumerateNamedMetadata(M);
-
-  SmallVector<std::pair<unsigned, MDNode *>, 8> MDs;
-  for (const GlobalVariable &GV : M.globals()) {
-    MDs.clear();
-    GV.getAllMetadata(MDs);
-    for (const auto &I : MDs)
-      // FIXME: Pass GV to EnumerateMetadata and arrange for the bitcode writer
-      // to write metadata to the global variable's own metadata block
-      // (PR28134).
-      EnumerateMetadata(nullptr, I.second);
-  }
-
-  // Enumerate types used by function bodies and argument lists.
-  for (const Function &F : M) {
-    for (const Argument &A : F.args())
-      EnumerateType(A.getType());
-
-    // Enumerate metadata attached to this function.
-    MDs.clear();
-    F.getAllMetadata(MDs);
-    for (const auto &I : MDs)
-      EnumerateMetadata(F.isDeclaration() ? nullptr : &F, I.second);
-
-    for (const BasicBlock &BB : F)
-      for (const Instruction &I : BB) {
-        for (const Use &Op : I.operands()) {
-          auto *MD = dyn_cast<MetadataAsValue>(&Op);
-          if (!MD) {
-            EnumerateOperandType(Op);
-            continue;
-          }
-
-          // Local metadata is enumerated during function-incorporation.
-          if (isa<LocalAsMetadata>(MD->getMetadata()))
-            continue;
-
-          EnumerateMetadata(&F, MD->getMetadata());
-        }
-        EnumerateType(I.getType());
-        if (const auto *Call = dyn_cast<CallBase>(&I))
-          EnumerateAttributes(Call->getAttributes());
-
-        // Enumerate metadata attached with this instruction.
-        MDs.clear();
-        I.getAllMetadataOtherThanDebugLoc(MDs);
-        for (unsigned i = 0, e = MDs.size(); i != e; ++i)
-          EnumerateMetadata(&F, MDs[i].second);
-
-        // Don't enumerate the location directly -- it has a special record
-        // type -- but enumerate its operands.
-        if (DILocation *L = I.getDebugLoc())
-          for (const Metadata *Op : L->operands())
-            EnumerateMetadata(&F, Op);
-      }
-  }
-
-  // Optimize constant ordering.
-  OptimizeConstants(FirstConstant, Values.size());
-
-  // Organize metadata ordering.
-  organizeMetadata();
-}
-
-unsigned ValueEnumerator::getInstructionID(const Instruction *Inst) const {
-  InstructionMapType::const_iterator I = InstructionMap.find(Inst);
-  assert(I != InstructionMap.end() && "Instruction is not mapped!");
-  return I->second;
-}
-
-unsigned ValueEnumerator::getComdatID(const Comdat *C) const {
-  unsigned ComdatID = Comdats.idFor(C);
-  assert(ComdatID && "Comdat not found!");
-  return ComdatID;
-}
-
-void ValueEnumerator::setInstructionID(const Instruction *I) {
-  InstructionMap[I] = InstructionCount++;
-}
-
-unsigned ValueEnumerator::getValueID(const Value *V) const {
-  if (auto *MD = dyn_cast<MetadataAsValue>(V))
-    return getMetadataID(MD->getMetadata());
-
-  ValueMapType::const_iterator I = ValueMap.find(V);
-  assert(I != ValueMap.end() && "Value not in slotcalculator!");
-  return I->second-1;
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-LLVM_DUMP_METHOD void ValueEnumerator::dump() const {
-  print(dbgs(), ValueMap, "Default");
-  dbgs() << '\n';
-  print(dbgs(), MetadataMap, "MetaData");
-  dbgs() << '\n';
-}
-#endif
-
-void ValueEnumerator::print(raw_ostream &OS, const ValueMapType &Map,
-                            const char *Name) const {
-  OS << "Map Name: " << Name << "\n";
-  OS << "Size: " << Map.size() << "\n";
-  for (ValueMapType::const_iterator I = Map.begin(),
-         E = Map.end(); I != E; ++I) {
-    const Value *V = I->first;
-    if (V->hasName())
-      OS << "Value: " << V->getName();
-    else
-      OS << "Value: [null]\n";
-    V->print(errs());
-    errs() << '\n';
-
-    OS << " Uses(" << V->getNumUses() << "):";
-    for (const Use &U : V->uses()) {
-      if (&U != &*V->use_begin())
-        OS << ",";
-      if(U->hasName())
-        OS << " " << U->getName();
-      else
-        OS << " [null]";
-
-    }
-    OS <<  "\n\n";
-  }
-}
-
-void ValueEnumerator::print(raw_ostream &OS, const MetadataMapType &Map,
-                            const char *Name) const {
-  OS << "Map Name: " << Name << "\n";
-  OS << "Size: " << Map.size() << "\n";
-  for (auto I = Map.begin(), E = Map.end(); I != E; ++I) {
-    const Metadata *MD = I->first;
-    OS << "Metadata: slot = " << I->second.ID << "\n";
-    OS << "Metadata: function = " << I->second.F << "\n";
-    MD->print(OS);
-    OS << "\n";
-  }
-}
-
-/// OptimizeConstants - Reorder constant pool for denser encoding.
-void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) {
-  if (CstStart == CstEnd || CstStart+1 == CstEnd) return;
-
-  if (ShouldPreserveUseListOrder)
-    // Optimizing constants makes the use-list order difficult to predict.
-    // Disable it for now when trying to preserve the order.
-    return;
-
-  std::stable_sort(Values.begin() + CstStart, Values.begin() + CstEnd,
-                   [this](const std::pair<const Value *, unsigned> &LHS,
-                          const std::pair<const Value *, unsigned> &RHS) {
-    // Sort by plane.
-    if (LHS.first->getType() != RHS.first->getType())
-      return getTypeID(LHS.first->getType()) < getTypeID(RHS.first->getType());
-    // Then by frequency.
-    return LHS.second > RHS.second;
-  });
-
-  // Ensure that integer and vector of integer constants are at the start of the
-  // constant pool.  This is important so that GEP structure indices come before
-  // gep constant exprs.
-  std::stable_partition(Values.begin() + CstStart, Values.begin() + CstEnd,
-                        isIntOrIntVectorValue);
-
-  // Rebuild the modified portion of ValueMap.
-  for (; CstStart != CstEnd; ++CstStart)
-    ValueMap[Values[CstStart].first] = CstStart+1;
-}
-
-/// EnumerateValueSymbolTable - Insert all of the values in the specified symbol
-/// table into the values table.
-void ValueEnumerator::EnumerateValueSymbolTable(const ValueSymbolTable &VST) {
-  for (ValueSymbolTable::const_iterator VI = VST.begin(), VE = VST.end();
-       VI != VE; ++VI)
-    EnumerateValue(VI->getValue());
-}
-
-/// Insert all of the values referenced by named metadata in the specified
-/// module.
-void ValueEnumerator::EnumerateNamedMetadata(const Module &M) {
-  for (const auto &I : M.named_metadata())
-    EnumerateNamedMDNode(&I);
-}
-
-void ValueEnumerator::EnumerateNamedMDNode(const NamedMDNode *MD) {
-  for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i)
-    EnumerateMetadata(nullptr, MD->getOperand(i));
-}
-
-unsigned ValueEnumerator::getMetadataFunctionID(const Function *F) const {
-  return F ? getValueID(F) + 1 : 0;
-}
-
-void ValueEnumerator::EnumerateMetadata(const Function *F, const Metadata *MD) {
-  EnumerateMetadata(getMetadataFunctionID(F), MD);
-}
-
-void ValueEnumerator::EnumerateFunctionLocalMetadata(
-    const Function &F, const LocalAsMetadata *Local) {
-  EnumerateFunctionLocalMetadata(getMetadataFunctionID(&F), Local);
-}
-
-void ValueEnumerator::dropFunctionFromMetadata(
-    MetadataMapType::value_type &FirstMD) {
-  SmallVector<const MDNode *, 64> Worklist;
-  auto push = [&Worklist](MetadataMapType::value_type &MD) {
-    auto &Entry = MD.second;
-
-    // Nothing to do if this metadata isn't tagged.
-    if (!Entry.F)
-      return;
-
-    // Drop the function tag.
-    Entry.F = 0;
-
-    // If this is has an ID and is an MDNode, then its operands have entries as
-    // well.  We need to drop the function from them too.
-    if (Entry.ID)
-      if (auto *N = dyn_cast<MDNode>(MD.first))
-        Worklist.push_back(N);
-  };
-  push(FirstMD);
-  while (!Worklist.empty())
-    for (const Metadata *Op : Worklist.pop_back_val()->operands()) {
-      if (!Op)
-        continue;
-      auto MD = MetadataMap.find(Op);
-      if (MD != MetadataMap.end())
-        push(*MD);
-    }
-}
-
-void ValueEnumerator::EnumerateMetadata(unsigned F, const Metadata *MD) {
-  // It's vital for reader efficiency that uniqued subgraphs are done in
-  // post-order; it's expensive when their operands have forward references.
-  // If a distinct node is referenced from a uniqued node, it'll be delayed
-  // until the uniqued subgraph has been completely traversed.
-  SmallVector<const MDNode *, 32> DelayedDistinctNodes;
-
-  // Start by enumerating MD, and then work through its transitive operands in
-  // post-order.  This requires a depth-first search.
-  SmallVector<std::pair<const MDNode *, MDNode::op_iterator>, 32> Worklist;
-  if (const MDNode *N = enumerateMetadataImpl(F, MD))
-    Worklist.push_back(std::make_pair(N, N->op_begin()));
-
-  while (!Worklist.empty()) {
-    const MDNode *N = Worklist.back().first;
-
-    // Enumerate operands until we hit a new node.  We need to traverse these
-    // nodes' operands before visiting the rest of N's operands.
-    MDNode::op_iterator I = std::find_if(
-        Worklist.back().second, N->op_end(),
-        [&](const Metadata *MD) { return enumerateMetadataImpl(F, MD); });
-    if (I != N->op_end()) {
-      auto *Op = cast<MDNode>(*I);
-      Worklist.back().second = ++I;
-
-      // Delay traversing Op if it's a distinct node and N is uniqued.
-      if (Op->isDistinct() && !N->isDistinct())
-        DelayedDistinctNodes.push_back(Op);
-      else
-        Worklist.push_back(std::make_pair(Op, Op->op_begin()));
-      continue;
-    }
-
-    // All the operands have been visited.  Now assign an ID.
-    Worklist.pop_back();
-    MDs.push_back(N);
-    MetadataMap[N].ID = MDs.size();
-
-    // Flush out any delayed distinct nodes; these are all the distinct nodes
-    // that are leaves in last uniqued subgraph.
-    if (Worklist.empty() || Worklist.back().first->isDistinct()) {
-      for (const MDNode *N : DelayedDistinctNodes)
-        Worklist.push_back(std::make_pair(N, N->op_begin()));
-      DelayedDistinctNodes.clear();
-    }
-  }
-}
-
-const MDNode *ValueEnumerator::enumerateMetadataImpl(unsigned F, const Metadata *MD) {
-  if (!MD)
-    return nullptr;
-
-  assert(
-      (isa<MDNode>(MD) || isa<MDString>(MD) || isa<ConstantAsMetadata>(MD)) &&
-      "Invalid metadata kind");
-
-  auto Insertion = MetadataMap.insert(std::make_pair(MD, MDIndex(F)));
-  MDIndex &Entry = Insertion.first->second;
-  if (!Insertion.second) {
-    // Already mapped.  If F doesn't match the function tag, drop it.
-    if (Entry.hasDifferentFunction(F))
-      dropFunctionFromMetadata(*Insertion.first);
-    return nullptr;
-  }
-
-  // Don't assign IDs to metadata nodes.
-  if (auto *N = dyn_cast<MDNode>(MD))
-    return N;
-
-  // Save the metadata.
-  MDs.push_back(MD);
-  Entry.ID = MDs.size();
-
-  // Enumerate the constant, if any.
-  if (auto *C = dyn_cast<ConstantAsMetadata>(MD))
-    EnumerateValue(C->getValue());
-
-  return nullptr;
-}
-
-/// EnumerateFunctionLocalMetadataa - Incorporate function-local metadata
-/// information reachable from the metadata.
-void ValueEnumerator::EnumerateFunctionLocalMetadata(
-    unsigned F, const LocalAsMetadata *Local) {
-  assert(F && "Expected a function");
-
-  // Check to see if it's already in!
-  MDIndex &Index = MetadataMap[Local];
-  if (Index.ID) {
-    assert(Index.F == F && "Expected the same function");
-    return;
-  }
-
-  MDs.push_back(Local);
-  Index.F = F;
-  Index.ID = MDs.size();
-
-  EnumerateValue(Local->getValue());
-}
-
-static unsigned getMetadataTypeOrder(const Metadata *MD) {
-  // Strings are emitted in bulk and must come first.
-  if (isa<MDString>(MD))
-    return 0;
-
-  // ConstantAsMetadata doesn't reference anything.  We may as well shuffle it
-  // to the front since we can detect it.
-  auto *N = dyn_cast<MDNode>(MD);
-  if (!N)
-    return 1;
-
-  // The reader is fast forward references for distinct node operands, but slow
-  // when uniqued operands are unresolved.
-  return N->isDistinct() ? 2 : 3;
-}
-
-void ValueEnumerator::organizeMetadata() {
-  assert(MetadataMap.size() == MDs.size() &&
-         "Metadata map and vector out of sync");
-
-  if (MDs.empty())
-    return;
-
-  // Copy out the index information from MetadataMap in order to choose a new
-  // order.
-  SmallVector<MDIndex, 64> Order;
-  Order.reserve(MetadataMap.size());
-  for (const Metadata *MD : MDs)
-    Order.push_back(MetadataMap.lookup(MD));
-
-  // Partition:
-  //   - by function, then
-  //   - by isa<MDString>
-  // and then sort by the original/current ID.  Since the IDs are guaranteed to
-  // be unique, the result of std::sort will be deterministic.  There's no need
-  // for std::stable_sort.
-  llvm::sort(Order, [this](MDIndex LHS, MDIndex RHS) {
-    return std::make_tuple(LHS.F, getMetadataTypeOrder(LHS.get(MDs)), LHS.ID) <
-           std::make_tuple(RHS.F, getMetadataTypeOrder(RHS.get(MDs)), RHS.ID);
-  });
-
-  // Rebuild MDs, index the metadata ranges for each function in FunctionMDs,
-  // and fix up MetadataMap.
-  std::vector<const Metadata *> OldMDs;
-  MDs.swap(OldMDs);
-  MDs.reserve(OldMDs.size());
-  for (unsigned I = 0, E = Order.size(); I != E && !Order[I].F; ++I) {
-    auto *MD = Order[I].get(OldMDs);
-    MDs.push_back(MD);
-    MetadataMap[MD].ID = I + 1;
-    if (isa<MDString>(MD))
-      ++NumMDStrings;
-  }
-
-  // Return early if there's nothing for the functions.
-  if (MDs.size() == Order.size())
-    return;
-
-  // Build the function metadata ranges.
-  MDRange R;
-  FunctionMDs.reserve(OldMDs.size());
-  unsigned PrevF = 0;
-  for (unsigned I = MDs.size(), E = Order.size(), ID = MDs.size(); I != E;
-       ++I) {
-    unsigned F = Order[I].F;
-    if (!PrevF) {
-      PrevF = F;
-    } else if (PrevF != F) {
-      R.Last = FunctionMDs.size();
-      std::swap(R, FunctionMDInfo[PrevF]);
-      R.First = FunctionMDs.size();
-
-      ID = MDs.size();
-      PrevF = F;
-    }
-
-    auto *MD = Order[I].get(OldMDs);
-    FunctionMDs.push_back(MD);
-    MetadataMap[MD].ID = ++ID;
-    if (isa<MDString>(MD))
-      ++R.NumStrings;
-  }
-  R.Last = FunctionMDs.size();
-  FunctionMDInfo[PrevF] = R;
-}
-
-void ValueEnumerator::incorporateFunctionMetadata(const Function &F) {
-  NumModuleMDs = MDs.size();
-
-  auto R = FunctionMDInfo.lookup(getValueID(&F) + 1);
-  NumMDStrings = R.NumStrings;
-  MDs.insert(MDs.end(), FunctionMDs.begin() + R.First,
-             FunctionMDs.begin() + R.Last);
-}
-
-void ValueEnumerator::EnumerateValue(const Value *V) {
-  assert(!V->getType()->isVoidTy() && "Can't insert void values!");
-  assert(!isa<MetadataAsValue>(V) && "EnumerateValue doesn't handle Metadata!");
-
-  // Check to see if it's already in!
-  unsigned &ValueID = ValueMap[V];
-  if (ValueID) {
-    // Increment use count.
-    Values[ValueID-1].second++;
-    return;
-  }
-
-  if (auto *GO = dyn_cast<GlobalObject>(V))
-    if (const Comdat *C = GO->getComdat())
-      Comdats.insert(C);
-
-  // Enumerate the type of this value.
-  EnumerateType(V->getType());
-
-  if (const Constant *C = dyn_cast<Constant>(V)) {
-    if (isa<GlobalValue>(C)) {
-      // Initializers for globals are handled explicitly elsewhere.
-    } else if (C->getNumOperands()) {
-      // If a constant has operands, enumerate them.  This makes sure that if a
-      // constant has uses (for example an array of const ints), that they are
-      // inserted also.
-
-      // We prefer to enumerate them with values before we enumerate the user
-      // itself.  This makes it more likely that we can avoid forward references
-      // in the reader.  We know that there can be no cycles in the constants
-      // graph that don't go through a global variable.
-      for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
-           I != E; ++I)
-        if (!isa<BasicBlock>(*I)) // Don't enumerate BB operand to BlockAddress.
-          EnumerateValue(*I);
-
-      // Finally, add the value.  Doing this could make the ValueID reference be
-      // dangling, don't reuse it.
-      Values.push_back(std::make_pair(V, 1U));
-      ValueMap[V] = Values.size();
-      return;
-    }
-  }
-
-  // Add the value.
-  Values.push_back(std::make_pair(V, 1U));
-  ValueID = Values.size();
-}
-
-
-void ValueEnumerator::EnumerateType(Type *Ty) {
-  unsigned *TypeID = &TypeMap[Ty];
-
-  // We've already seen this type.
-  if (*TypeID)
-    return;
-
-  // If it is a non-anonymous struct, mark the type as being visited so that we
-  // don't recursively visit it.  This is safe because we allow forward
-  // references of these in the bitcode reader.
-  if (StructType *STy = dyn_cast<StructType>(Ty))
-    if (!STy->isLiteral())
-      *TypeID = ~0U;
-
-  // Enumerate all of the subtypes before we enumerate this type.  This ensures
-  // that the type will be enumerated in an order that can be directly built.
-  for (Type *SubTy : Ty->subtypes())
-    EnumerateType(SubTy);
-
-  // Refresh the TypeID pointer in case the table rehashed.
-  TypeID = &TypeMap[Ty];
-
-  // Check to see if we got the pointer another way.  This can happen when
-  // enumerating recursive types that hit the base case deeper than they start.
-  //
-  // If this is actually a struct that we are treating as forward ref'able,
-  // then emit the definition now that all of its contents are available.
-  if (*TypeID && *TypeID != ~0U)
-    return;
-
-  // Add this type now that its contents are all happily enumerated.
-  Types.push_back(Ty);
-
-  *TypeID = Types.size();
-}
-
-// Enumerate the types for the specified value.  If the value is a constant,
-// walk through it, enumerating the types of the constant.
-void ValueEnumerator::EnumerateOperandType(const Value *V) {
-  EnumerateType(V->getType());
-
-  assert(!isa<MetadataAsValue>(V) && "Unexpected metadata operand");
-
-  const Constant *C = dyn_cast<Constant>(V);
-  if (!C)
-    return;
-
-  // If this constant is already enumerated, ignore it, we know its type must
-  // be enumerated.
-  if (ValueMap.count(C))
-    return;
-
-  // This constant may have operands, make sure to enumerate the types in
-  // them.
-  for (const Value *Op : C->operands()) {
-    // Don't enumerate basic blocks here, this happens as operands to
-    // blockaddress.
-    if (isa<BasicBlock>(Op))
-      continue;
-
-    EnumerateOperandType(Op);
-  }
-}
-
-void ValueEnumerator::EnumerateAttributes(AttributeList PAL) {
-  if (PAL.isEmpty()) return;  // null is always 0.
-
-  // Do a lookup.
-  unsigned &Entry = AttributeListMap[PAL];
-  if (Entry == 0) {
-    // Never saw this before, add it.
-    AttributeLists.push_back(PAL);
-    Entry = AttributeLists.size();
-  }
-
-  // Do lookups for all attribute groups.
-  for (unsigned i = PAL.index_begin(), e = PAL.index_end(); i != e; ++i) {
-    AttributeSet AS = PAL.getAttributes(i);
-    if (!AS.hasAttributes())
-      continue;
-    IndexAndAttrSet Pair = {i, AS};
-    unsigned &Entry = AttributeGroupMap[Pair];
-    if (Entry == 0) {
-      AttributeGroups.push_back(Pair);
-      Entry = AttributeGroups.size();
-    }
-  }
-}
-
-void ValueEnumerator::incorporateFunction(const Function &F) {
-  InstructionCount = 0;
-  NumModuleValues = Values.size();
-
-  // Add global metadata to the function block.  This doesn't include
-  // LocalAsMetadata.
-  incorporateFunctionMetadata(F);
-
-  // Adding function arguments to the value table.
-  for (const auto &I : F.args()) {
-    EnumerateValue(&I);
-    if (I.hasAttribute(Attribute::ByVal))
-      EnumerateType(I.getParamByValType());
-  }
-  FirstFuncConstantID = Values.size();
-
-  // Add all function-level constants to the value table.
-  for (const BasicBlock &BB : F) {
-    for (const Instruction &I : BB)
-      for (const Use &OI : I.operands()) {
-        if ((isa<Constant>(OI) && !isa<GlobalValue>(OI)) || isa<InlineAsm>(OI))
-          EnumerateValue(OI);
-      }
-    BasicBlocks.push_back(&BB);
-    ValueMap[&BB] = BasicBlocks.size();
-  }
-
-  // Optimize the constant layout.
-  OptimizeConstants(FirstFuncConstantID, Values.size());
-
-  // Add the function's parameter attributes so they are available for use in
-  // the function's instruction.
-  EnumerateAttributes(F.getAttributes());
-
-  FirstInstID = Values.size();
-
-  SmallVector<LocalAsMetadata *, 8> FnLocalMDVector;
-  // Add all of the instructions.
-  for (const BasicBlock &BB : F) {
-    for (const Instruction &I : BB) {
-      for (const Use &OI : I.operands()) {
-        if (auto *MD = dyn_cast<MetadataAsValue>(&OI))
-          if (auto *Local = dyn_cast<LocalAsMetadata>(MD->getMetadata()))
-            // Enumerate metadata after the instructions they might refer to.
-            FnLocalMDVector.push_back(Local);
-      }
-
-      if (!I.getType()->isVoidTy())
-        EnumerateValue(&I);
-    }
-  }
-
-  // Add all of the function-local metadata.
-  for (unsigned i = 0, e = FnLocalMDVector.size(); i != e; ++i) {
-    // At this point, every local values have been incorporated, we shouldn't
-    // have a metadata operand that references a value that hasn't been seen.
-    assert(ValueMap.count(FnLocalMDVector[i]->getValue()) &&
-           "Missing value for metadata operand");
-    EnumerateFunctionLocalMetadata(F, FnLocalMDVector[i]);
-  }
-}
-
-void ValueEnumerator::purgeFunction() {
-  /// Remove purged values from the ValueMap.
-  for (unsigned i = NumModuleValues, e = Values.size(); i != e; ++i)
-    ValueMap.erase(Values[i].first);
-  for (unsigned i = NumModuleMDs, e = MDs.size(); i != e; ++i)
-    MetadataMap.erase(MDs[i]);
-  for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i)
-    ValueMap.erase(BasicBlocks[i]);
-
-  Values.resize(NumModuleValues);
-  MDs.resize(NumModuleMDs);
-  BasicBlocks.clear();
-  NumMDStrings = 0;
-}
-
-static void IncorporateFunctionInfoGlobalBBIDs(const Function *F,
-                                 DenseMap<const BasicBlock*, unsigned> &IDMap) {
-  unsigned Counter = 0;
-  for (const BasicBlock &BB : *F)
-    IDMap[&BB] = ++Counter;
-}
-
-/// getGlobalBasicBlockID - This returns the function-specific ID for the
-/// specified basic block.  This is relatively expensive information, so it
-/// should only be used by rare constructs such as address-of-label.
-unsigned ValueEnumerator::getGlobalBasicBlockID(const BasicBlock *BB) const {
-  unsigned &Idx = GlobalBasicBlockIDs[BB];
-  if (Idx != 0)
-    return Idx-1;
-
-  IncorporateFunctionInfoGlobalBBIDs(BB->getParent(), GlobalBasicBlockIDs);
-  return getGlobalBasicBlockID(BB);
-}
-
-uint64_t ValueEnumerator::computeBitsRequiredForTypeIndicies() const {
-  return Log2_32_Ceil(getTypes().size() + 1);
-}