Metadata.cpp revision de2d8694e25a814696358e95141f4b1aa4d8847e 
1//===- Metadata.cpp - Implement Metadata classes --------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the Metadata classes.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/IR/Metadata.h"
15#include "LLVMContextImpl.h"
16#include "MetadataImpl.h"
17#include "SymbolTableListTraitsImpl.h"
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/ADT/SmallSet.h"
20#include "llvm/ADT/StringMap.h"
21#include "llvm/IR/ConstantRange.h"
22#include "llvm/IR/DebugInfoMetadata.h"
23#include "llvm/IR/Instruction.h"
24#include "llvm/IR/LLVMContext.h"
25#include "llvm/IR/Module.h"
26#include "llvm/IR/ValueHandle.h"
27
28using namespace llvm;
29
30MetadataAsValue::MetadataAsValue(Type *Ty, Metadata *MD)
31    : Value(Ty, MetadataAsValueVal), MD(MD) {
32  track();
33}
34
35MetadataAsValue::~MetadataAsValue() {
36  getType()->getContext().pImpl->MetadataAsValues.erase(MD);
37  untrack();
38}
39
40/// Canonicalize metadata arguments to intrinsics.
41///
42/// To support bitcode upgrades (and assembly semantic sugar) for \a
43/// MetadataAsValue, we need to canonicalize certain metadata.
44///
45///   - nullptr is replaced by an empty MDNode.
46///   - An MDNode with a single null operand is replaced by an empty MDNode.
47///   - An MDNode whose only operand is a \a ConstantAsMetadata gets skipped.
48///
49/// This maintains readability of bitcode from when metadata was a type of
50/// value, and these bridges were unnecessary.
51static Metadata *canonicalizeMetadataForValue(LLVMContext &Context,
52                                              Metadata *MD) {
53  if (!MD)
54    // !{}
55    return MDNode::get(Context, None);
56
57  // Return early if this isn't a single-operand MDNode.
58  auto *N = dyn_cast<MDNode>(MD);
59  if (!N || N->getNumOperands() != 1)
60    return MD;
61
62  if (!N->getOperand(0))
63    // !{}
64    return MDNode::get(Context, None);
65
66  if (auto *C = dyn_cast<ConstantAsMetadata>(N->getOperand(0)))
67    // Look through the MDNode.
68    return C;
69
70  return MD;
71}
72
73MetadataAsValue *MetadataAsValue::get(LLVMContext &Context, Metadata *MD) {
74  MD = canonicalizeMetadataForValue(Context, MD);
75  auto *&Entry = Context.pImpl->MetadataAsValues[MD];
76  if (!Entry)
77    Entry = new MetadataAsValue(Type::getMetadataTy(Context), MD);
78  return Entry;
79}
80
81MetadataAsValue *MetadataAsValue::getIfExists(LLVMContext &Context,
82                                              Metadata *MD) {
83  MD = canonicalizeMetadataForValue(Context, MD);
84  auto &Store = Context.pImpl->MetadataAsValues;
85  return Store.lookup(MD);
86}
87
88void MetadataAsValue::handleChangedMetadata(Metadata *MD) {
89  LLVMContext &Context = getContext();
90  MD = canonicalizeMetadataForValue(Context, MD);
91  auto &Store = Context.pImpl->MetadataAsValues;
92
93  // Stop tracking the old metadata.
94  Store.erase(this->MD);
95  untrack();
96  this->MD = nullptr;
97
98  // Start tracking MD, or RAUW if necessary.
99  auto *&Entry = Store[MD];
100  if (Entry) {
101    replaceAllUsesWith(Entry);
102    delete this;
103    return;
104  }
105
106  this->MD = MD;
107  track();
108  Entry = this;
109}
110
111void MetadataAsValue::track() {
112  if (MD)
113    MetadataTracking::track(&MD, *MD, *this);
114}
115
116void MetadataAsValue::untrack() {
117  if (MD)
118    MetadataTracking::untrack(MD);
119}
120
121bool MetadataTracking::track(void *Ref, Metadata &MD, OwnerTy Owner) {
122  assert(Ref && "Expected live reference");
123  assert((Owner || *static_cast<Metadata **>(Ref) == &MD) &&
124         "Reference without owner must be direct");
125  if (auto *R = ReplaceableMetadataImpl::getOrCreate(MD)) {
126    R->addRef(Ref, Owner);
127    return true;
128  }
129  if (auto *PH = dyn_cast<DistinctMDOperandPlaceholder>(&MD)) {
130    assert(!PH->Use && "Placeholders can only be used once");
131    assert(!Owner && "Unexpected callback to owner");
132    PH->Use = static_cast<Metadata **>(Ref);
133    return true;
134  }
135  return false;
136}
137
138void MetadataTracking::untrack(void *Ref, Metadata &MD) {
139  assert(Ref && "Expected live reference");
140  if (auto *R = ReplaceableMetadataImpl::getIfExists(MD))
141    R->dropRef(Ref);
142  else if (auto *PH = dyn_cast<DistinctMDOperandPlaceholder>(&MD))
143    PH->Use = nullptr;
144}
145
146bool MetadataTracking::retrack(void *Ref, Metadata &MD, void *New) {
147  assert(Ref && "Expected live reference");
148  assert(New && "Expected live reference");
149  assert(Ref != New && "Expected change");
150  if (auto *R = ReplaceableMetadataImpl::getIfExists(MD)) {
151    R->moveRef(Ref, New, MD);
152    return true;
153  }
154  assert(!isa<DistinctMDOperandPlaceholder>(MD) &&
155         "Unexpected move of an MDOperand");
156  assert(!isReplaceable(MD) &&
157         "Expected un-replaceable metadata, since we didn't move a reference");
158  return false;
159}
160
161bool MetadataTracking::isReplaceable(const Metadata &MD) {
162  return ReplaceableMetadataImpl::isReplaceable(MD);
163}
164
165void ReplaceableMetadataImpl::addRef(void *Ref, OwnerTy Owner) {
166  bool WasInserted =
167      UseMap.insert(std::make_pair(Ref, std::make_pair(Owner, NextIndex)))
168          .second;
169  (void)WasInserted;
170  assert(WasInserted && "Expected to add a reference");
171
172  ++NextIndex;
173  assert(NextIndex != 0 && "Unexpected overflow");
174}
175
176void ReplaceableMetadataImpl::dropRef(void *Ref) {
177  bool WasErased = UseMap.erase(Ref);
178  (void)WasErased;
179  assert(WasErased && "Expected to drop a reference");
180}
181
182void ReplaceableMetadataImpl::moveRef(void *Ref, void *New,
183                                      const Metadata &MD) {
184  auto I = UseMap.find(Ref);
185  assert(I != UseMap.end() && "Expected to move a reference");
186  auto OwnerAndIndex = I->second;
187  UseMap.erase(I);
188  bool WasInserted = UseMap.insert(std::make_pair(New, OwnerAndIndex)).second;
189  (void)WasInserted;
190  assert(WasInserted && "Expected to add a reference");
191
192  // Check that the references are direct if there's no owner.
193  (void)MD;
194  assert((OwnerAndIndex.first || *static_cast<Metadata **>(Ref) == &MD) &&
195         "Reference without owner must be direct");
196  assert((OwnerAndIndex.first || *static_cast<Metadata **>(New) == &MD) &&
197         "Reference without owner must be direct");
198}
199
200void ReplaceableMetadataImpl::replaceAllUsesWith(Metadata *MD) {
201  if (UseMap.empty())
202    return;
203
204  // Copy out uses since UseMap will get touched below.
205  typedef std::pair<void *, std::pair<OwnerTy, uint64_t>> UseTy;
206  SmallVector<UseTy, 8> Uses(UseMap.begin(), UseMap.end());
207  std::sort(Uses.begin(), Uses.end(), [](const UseTy &L, const UseTy &R) {
208    return L.second.second < R.second.second;
209  });
210  for (const auto &Pair : Uses) {
211    // Check that this Ref hasn't disappeared after RAUW (when updating a
212    // previous Ref).
213    if (!UseMap.count(Pair.first))
214      continue;
215
216    OwnerTy Owner = Pair.second.first;
217    if (!Owner) {
218      // Update unowned tracking references directly.
219      Metadata *&Ref = *static_cast<Metadata **>(Pair.first);
220      Ref = MD;
221      if (MD)
222        MetadataTracking::track(Ref);
223      UseMap.erase(Pair.first);
224      continue;
225    }
226
227    // Check for MetadataAsValue.
228    if (Owner.is<MetadataAsValue *>()) {
229      Owner.get<MetadataAsValue *>()->handleChangedMetadata(MD);
230      continue;
231    }
232
233    // There's a Metadata owner -- dispatch.
234    Metadata *OwnerMD = Owner.get<Metadata *>();
235    switch (OwnerMD->getMetadataID()) {
236#define HANDLE_METADATA_LEAF(CLASS)                                            \
237  case Metadata::CLASS##Kind:                                                  \
238    cast<CLASS>(OwnerMD)->handleChangedOperand(Pair.first, MD);                \
239    continue;
240#include "llvm/IR/Metadata.def"
241    default:
242      llvm_unreachable("Invalid metadata subclass");
243    }
244  }
245  assert(UseMap.empty() && "Expected all uses to be replaced");
246}
247
248void ReplaceableMetadataImpl::resolveAllUses(bool ResolveUsers) {
249  if (UseMap.empty())
250    return;
251
252  if (!ResolveUsers) {
253    UseMap.clear();
254    return;
255  }
256
257  // Copy out uses since UseMap could get touched below.
258  typedef std::pair<void *, std::pair<OwnerTy, uint64_t>> UseTy;
259  SmallVector<UseTy, 8> Uses(UseMap.begin(), UseMap.end());
260  std::sort(Uses.begin(), Uses.end(), [](const UseTy &L, const UseTy &R) {
261    return L.second.second < R.second.second;
262  });
263  UseMap.clear();
264  for (const auto &Pair : Uses) {
265    auto Owner = Pair.second.first;
266    if (!Owner)
267      continue;
268    if (Owner.is<MetadataAsValue *>())
269      continue;
270
271    // Resolve MDNodes that point at this.
272    auto *OwnerMD = dyn_cast<MDNode>(Owner.get<Metadata *>());
273    if (!OwnerMD)
274      continue;
275    if (OwnerMD->isResolved())
276      continue;
277    OwnerMD->decrementUnresolvedOperandCount();
278  }
279}
280
281ReplaceableMetadataImpl *ReplaceableMetadataImpl::getOrCreate(Metadata &MD) {
282  if (auto *N = dyn_cast<MDNode>(&MD))
283    return N->isResolved() ? nullptr : N->Context.getOrCreateReplaceableUses();
284  return dyn_cast<ValueAsMetadata>(&MD);
285}
286
287ReplaceableMetadataImpl *ReplaceableMetadataImpl::getIfExists(Metadata &MD) {
288  if (auto *N = dyn_cast<MDNode>(&MD))
289    return N->isResolved() ? nullptr : N->Context.getReplaceableUses();
290  return dyn_cast<ValueAsMetadata>(&MD);
291}
292
293bool ReplaceableMetadataImpl::isReplaceable(const Metadata &MD) {
294  if (auto *N = dyn_cast<MDNode>(&MD))
295    return !N->isResolved();
296  return dyn_cast<ValueAsMetadata>(&MD);
297}
298
299static Function *getLocalFunction(Value *V) {
300  assert(V && "Expected value");
301  if (auto *A = dyn_cast<Argument>(V))
302    return A->getParent();
303  if (BasicBlock *BB = cast<Instruction>(V)->getParent())
304    return BB->getParent();
305  return nullptr;
306}
307
308ValueAsMetadata *ValueAsMetadata::get(Value *V) {
309  assert(V && "Unexpected null Value");
310
311  auto &Context = V->getContext();
312  auto *&Entry = Context.pImpl->ValuesAsMetadata[V];
313  if (!Entry) {
314    assert((isa<Constant>(V) || isa<Argument>(V) || isa<Instruction>(V)) &&
315           "Expected constant or function-local value");
316    assert(!V->IsUsedByMD &&
317           "Expected this to be the only metadata use");
318    V->IsUsedByMD = true;
319    if (auto *C = dyn_cast<Constant>(V))
320      Entry = new ConstantAsMetadata(C);
321    else
322      Entry = new LocalAsMetadata(V);
323  }
324
325  return Entry;
326}
327
328ValueAsMetadata *ValueAsMetadata::getIfExists(Value *V) {
329  assert(V && "Unexpected null Value");
330  return V->getContext().pImpl->ValuesAsMetadata.lookup(V);
331}
332
333void ValueAsMetadata::handleDeletion(Value *V) {
334  assert(V && "Expected valid value");
335
336  auto &Store = V->getType()->getContext().pImpl->ValuesAsMetadata;
337  auto I = Store.find(V);
338  if (I == Store.end())
339    return;
340
341  // Remove old entry from the map.
342  ValueAsMetadata *MD = I->second;
343  assert(MD && "Expected valid metadata");
344  assert(MD->getValue() == V && "Expected valid mapping");
345  Store.erase(I);
346
347  // Delete the metadata.
348  MD->replaceAllUsesWith(nullptr);
349  delete MD;
350}
351
352void ValueAsMetadata::handleRAUW(Value *From, Value *To) {
353  assert(From && "Expected valid value");
354  assert(To && "Expected valid value");
355  assert(From != To && "Expected changed value");
356  assert(From->getType() == To->getType() && "Unexpected type change");
357
358  LLVMContext &Context = From->getType()->getContext();
359  auto &Store = Context.pImpl->ValuesAsMetadata;
360  auto I = Store.find(From);
361  if (I == Store.end()) {
362    assert(!From->IsUsedByMD &&
363           "Expected From not to be used by metadata");
364    return;
365  }
366
367  // Remove old entry from the map.
368  assert(From->IsUsedByMD &&
369         "Expected From to be used by metadata");
370  From->IsUsedByMD = false;
371  ValueAsMetadata *MD = I->second;
372  assert(MD && "Expected valid metadata");
373  assert(MD->getValue() == From && "Expected valid mapping");
374  Store.erase(I);
375
376  if (isa<LocalAsMetadata>(MD)) {
377    if (auto *C = dyn_cast<Constant>(To)) {
378      // Local became a constant.
379      MD->replaceAllUsesWith(ConstantAsMetadata::get(C));
380      delete MD;
381      return;
382    }
383    if (getLocalFunction(From) && getLocalFunction(To) &&
384        getLocalFunction(From) != getLocalFunction(To)) {
385      // Function changed.
386      MD->replaceAllUsesWith(nullptr);
387      delete MD;
388      return;
389    }
390  } else if (!isa<Constant>(To)) {
391    // Changed to function-local value.
392    MD->replaceAllUsesWith(nullptr);
393    delete MD;
394    return;
395  }
396
397  auto *&Entry = Store[To];
398  if (Entry) {
399    // The target already exists.
400    MD->replaceAllUsesWith(Entry);
401    delete MD;
402    return;
403  }
404
405  // Update MD in place (and update the map entry).
406  assert(!To->IsUsedByMD &&
407         "Expected this to be the only metadata use");
408  To->IsUsedByMD = true;
409  MD->V = To;
410  Entry = MD;
411}
412
413//===----------------------------------------------------------------------===//
414// MDString implementation.
415//
416
417MDString *MDString::get(LLVMContext &Context, StringRef Str) {
418  auto &Store = Context.pImpl->MDStringCache;
419  auto I = Store.emplace_second(Str);
420  auto &MapEntry = I.first->getValue();
421  if (!I.second)
422    return &MapEntry;
423  MapEntry.Entry = &*I.first;
424  return &MapEntry;
425}
426
427StringRef MDString::getString() const {
428  assert(Entry && "Expected to find string map entry");
429  return Entry->first();
430}
431
432//===----------------------------------------------------------------------===//
433// MDNode implementation.
434//
435
436// Assert that the MDNode types will not be unaligned by the objects
437// prepended to them.
438#define HANDLE_MDNODE_LEAF(CLASS)                                              \
439  static_assert(                                                               \
440      llvm::AlignOf<uint64_t>::Alignment >= llvm::AlignOf<CLASS>::Alignment,   \
441      "Alignment is insufficient after objects prepended to " #CLASS);
442#include "llvm/IR/Metadata.def"
443
444void *MDNode::operator new(size_t Size, unsigned NumOps) {
445  size_t OpSize = NumOps * sizeof(MDOperand);
446  // uint64_t is the most aligned type we need support (ensured by static_assert
447  // above)
448  OpSize = alignTo(OpSize, llvm::alignOf<uint64_t>());
449  void *Ptr = reinterpret_cast<char *>(::operator new(OpSize + Size)) + OpSize;
450  MDOperand *O = static_cast<MDOperand *>(Ptr);
451  for (MDOperand *E = O - NumOps; O != E; --O)
452    (void)new (O - 1) MDOperand;
453  return Ptr;
454}
455
456void MDNode::operator delete(void *Mem) {
457  MDNode *N = static_cast<MDNode *>(Mem);
458  size_t OpSize = N->NumOperands * sizeof(MDOperand);
459  OpSize = alignTo(OpSize, llvm::alignOf<uint64_t>());
460
461  MDOperand *O = static_cast<MDOperand *>(Mem);
462  for (MDOperand *E = O - N->NumOperands; O != E; --O)
463    (O - 1)->~MDOperand();
464  ::operator delete(reinterpret_cast<char *>(Mem) - OpSize);
465}
466
467MDNode::MDNode(LLVMContext &Context, unsigned ID, StorageType Storage,
468               ArrayRef<Metadata *> Ops1, ArrayRef<Metadata *> Ops2)
469    : Metadata(ID, Storage), NumOperands(Ops1.size() + Ops2.size()),
470      NumUnresolved(0), Context(Context) {
471  unsigned Op = 0;
472  for (Metadata *MD : Ops1)
473    setOperand(Op++, MD);
474  for (Metadata *MD : Ops2)
475    setOperand(Op++, MD);
476
477  if (!isUniqued())
478    return;
479
480  // Count the unresolved operands.  If there are any, RAUW support will be
481  // added lazily on first reference.
482  countUnresolvedOperands();
483}
484
485TempMDNode MDNode::clone() const {
486  switch (getMetadataID()) {
487  default:
488    llvm_unreachable("Invalid MDNode subclass");
489#define HANDLE_MDNODE_LEAF(CLASS)                                              \
490  case CLASS##Kind:                                                            \
491    return cast<CLASS>(this)->cloneImpl();
492#include "llvm/IR/Metadata.def"
493  }
494}
495
496static bool isOperandUnresolved(Metadata *Op) {
497  if (auto *N = dyn_cast_or_null<MDNode>(Op))
498    return !N->isResolved();
499  return false;
500}
501
502void MDNode::countUnresolvedOperands() {
503  assert(NumUnresolved == 0 && "Expected unresolved ops to be uncounted");
504  assert(isUniqued() && "Expected this to be uniqued");
505  NumUnresolved = count_if(operands(), isOperandUnresolved);
506}
507
508void MDNode::makeUniqued() {
509  assert(isTemporary() && "Expected this to be temporary");
510  assert(!isResolved() && "Expected this to be unresolved");
511
512  // Enable uniquing callbacks.
513  for (auto &Op : mutable_operands())
514    Op.reset(Op.get(), this);
515
516  // Make this 'uniqued'.
517  Storage = Uniqued;
518  countUnresolvedOperands();
519  if (!NumUnresolved) {
520    dropReplaceableUses();
521    assert(isResolved() && "Expected this to be resolved");
522  }
523
524  assert(isUniqued() && "Expected this to be uniqued");
525}
526
527void MDNode::makeDistinct() {
528  assert(isTemporary() && "Expected this to be temporary");
529  assert(!isResolved() && "Expected this to be unresolved");
530
531  // Drop RAUW support and store as a distinct node.
532  dropReplaceableUses();
533  storeDistinctInContext();
534
535  assert(isDistinct() && "Expected this to be distinct");
536  assert(isResolved() && "Expected this to be resolved");
537}
538
539void MDNode::resolve() {
540  assert(isUniqued() && "Expected this to be uniqued");
541  assert(!isResolved() && "Expected this to be unresolved");
542
543  NumUnresolved = 0;
544  dropReplaceableUses();
545
546  assert(isResolved() && "Expected this to be resolved");
547}
548
549void MDNode::dropReplaceableUses() {
550  assert(!NumUnresolved && "Unexpected unresolved operand");
551
552  // Drop any RAUW support.
553  if (Context.hasReplaceableUses())
554    Context.takeReplaceableUses()->resolveAllUses();
555}
556
557void MDNode::resolveAfterOperandChange(Metadata *Old, Metadata *New) {
558  assert(isUniqued() && "Expected this to be uniqued");
559  assert(NumUnresolved != 0 && "Expected unresolved operands");
560
561  // Check if an operand was resolved.
562  if (!isOperandUnresolved(Old)) {
563    if (isOperandUnresolved(New))
564      // An operand was un-resolved!
565      ++NumUnresolved;
566  } else if (!isOperandUnresolved(New))
567    decrementUnresolvedOperandCount();
568}
569
570void MDNode::decrementUnresolvedOperandCount() {
571  assert(!isResolved() && "Expected this to be unresolved");
572  if (isTemporary())
573    return;
574
575  assert(isUniqued() && "Expected this to be uniqued");
576  if (--NumUnresolved)
577    return;
578
579  // Last unresolved operand has just been resolved.
580  dropReplaceableUses();
581  assert(isResolved() && "Expected this to become resolved");
582}
583
584void MDNode::resolveCycles() {
585  if (isResolved())
586    return;
587
588  // Resolve this node immediately.
589  resolve();
590
591  // Resolve all operands.
592  for (const auto &Op : operands()) {
593    auto *N = dyn_cast_or_null<MDNode>(Op);
594    if (!N)
595      continue;
596
597    assert(!N->isTemporary() &&
598           "Expected all forward declarations to be resolved");
599    if (!N->isResolved())
600      N->resolveCycles();
601  }
602}
603
604static bool hasSelfReference(MDNode *N) {
605  for (Metadata *MD : N->operands())
606    if (MD == N)
607      return true;
608  return false;
609}
610
611MDNode *MDNode::replaceWithPermanentImpl() {
612  switch (getMetadataID()) {
613  default:
614    // If this type isn't uniquable, replace with a distinct node.
615    return replaceWithDistinctImpl();
616
617#define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS)                                    \
618  case CLASS##Kind:                                                            \
619    break;
620#include "llvm/IR/Metadata.def"
621  }
622
623  // Even if this type is uniquable, self-references have to be distinct.
624  if (hasSelfReference(this))
625    return replaceWithDistinctImpl();
626  return replaceWithUniquedImpl();
627}
628
629MDNode *MDNode::replaceWithUniquedImpl() {
630  // Try to uniquify in place.
631  MDNode *UniquedNode = uniquify();
632
633  if (UniquedNode == this) {
634    makeUniqued();
635    return this;
636  }
637
638  // Collision, so RAUW instead.
639  replaceAllUsesWith(UniquedNode);
640  deleteAsSubclass();
641  return UniquedNode;
642}
643
644MDNode *MDNode::replaceWithDistinctImpl() {
645  makeDistinct();
646  return this;
647}
648
649void MDTuple::recalculateHash() {
650  setHash(MDTupleInfo::KeyTy::calculateHash(this));
651}
652
653void MDNode::dropAllReferences() {
654  for (unsigned I = 0, E = NumOperands; I != E; ++I)
655    setOperand(I, nullptr);
656  if (Context.hasReplaceableUses()) {
657    Context.getReplaceableUses()->resolveAllUses(/* ResolveUsers */ false);
658    (void)Context.takeReplaceableUses();
659  }
660}
661
662void MDNode::handleChangedOperand(void *Ref, Metadata *New) {
663  unsigned Op = static_cast<MDOperand *>(Ref) - op_begin();
664  assert(Op < getNumOperands() && "Expected valid operand");
665
666  if (!isUniqued()) {
667    // This node is not uniqued.  Just set the operand and be done with it.
668    setOperand(Op, New);
669    return;
670  }
671
672  // This node is uniqued.
673  eraseFromStore();
674
675  Metadata *Old = getOperand(Op);
676  setOperand(Op, New);
677
678  // Drop uniquing for self-reference cycles.
679  if (New == this) {
680    if (!isResolved())
681      resolve();
682    storeDistinctInContext();
683    return;
684  }
685
686  // Re-unique the node.
687  auto *Uniqued = uniquify();
688  if (Uniqued == this) {
689    if (!isResolved())
690      resolveAfterOperandChange(Old, New);
691    return;
692  }
693
694  // Collision.
695  if (!isResolved()) {
696    // Still unresolved, so RAUW.
697    //
698    // First, clear out all operands to prevent any recursion (similar to
699    // dropAllReferences(), but we still need the use-list).
700    for (unsigned O = 0, E = getNumOperands(); O != E; ++O)
701      setOperand(O, nullptr);
702    if (Context.hasReplaceableUses())
703      Context.getReplaceableUses()->replaceAllUsesWith(Uniqued);
704    deleteAsSubclass();
705    return;
706  }
707
708  // Store in non-uniqued form if RAUW isn't possible.
709  storeDistinctInContext();
710}
711
712void MDNode::deleteAsSubclass() {
713  switch (getMetadataID()) {
714  default:
715    llvm_unreachable("Invalid subclass of MDNode");
716#define HANDLE_MDNODE_LEAF(CLASS)                                              \
717  case CLASS##Kind:                                                            \
718    delete cast<CLASS>(this);                                                  \
719    break;
720#include "llvm/IR/Metadata.def"
721  }
722}
723
724template <class T, class InfoT>
725static T *uniquifyImpl(T *N, DenseSet<T *, InfoT> &Store) {
726  if (T *U = getUniqued(Store, N))
727    return U;
728
729  Store.insert(N);
730  return N;
731}
732
733template <class NodeTy> struct MDNode::HasCachedHash {
734  typedef char Yes[1];
735  typedef char No[2];
736  template <class U, U Val> struct SFINAE {};
737
738  template <class U>
739  static Yes &check(SFINAE<void (U::*)(unsigned), &U::setHash> *);
740  template <class U> static No &check(...);
741
742  static const bool value = sizeof(check<NodeTy>(nullptr)) == sizeof(Yes);
743};
744
745MDNode *MDNode::uniquify() {
746  assert(!hasSelfReference(this) && "Cannot uniquify a self-referencing node");
747
748  // Try to insert into uniquing store.
749  switch (getMetadataID()) {
750  default:
751    llvm_unreachable("Invalid or non-uniquable subclass of MDNode");
752#define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS)                                    \
753  case CLASS##Kind: {                                                          \
754    CLASS *SubclassThis = cast<CLASS>(this);                                   \
755    std::integral_constant<bool, HasCachedHash<CLASS>::value>                  \
756        ShouldRecalculateHash;                                                 \
757    dispatchRecalculateHash(SubclassThis, ShouldRecalculateHash);              \
758    return uniquifyImpl(SubclassThis, getContext().pImpl->CLASS##s);           \
759  }
760#include "llvm/IR/Metadata.def"
761  }
762}
763
764void MDNode::eraseFromStore() {
765  switch (getMetadataID()) {
766  default:
767    llvm_unreachable("Invalid or non-uniquable subclass of MDNode");
768#define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS)                                    \
769  case CLASS##Kind:                                                            \
770    getContext().pImpl->CLASS##s.erase(cast<CLASS>(this));                     \
771    break;
772#include "llvm/IR/Metadata.def"
773  }
774}
775
776MDTuple *MDTuple::getImpl(LLVMContext &Context, ArrayRef<Metadata *> MDs,
777                          StorageType Storage, bool ShouldCreate) {
778  unsigned Hash = 0;
779  if (Storage == Uniqued) {
780    MDTupleInfo::KeyTy Key(MDs);
781    if (auto *N = getUniqued(Context.pImpl->MDTuples, Key))
782      return N;
783    if (!ShouldCreate)
784      return nullptr;
785    Hash = Key.getHash();
786  } else {
787    assert(ShouldCreate && "Expected non-uniqued nodes to always be created");
788  }
789
790  return storeImpl(new (MDs.size()) MDTuple(Context, Storage, Hash, MDs),
791                   Storage, Context.pImpl->MDTuples);
792}
793
794void MDNode::deleteTemporary(MDNode *N) {
795  assert(N->isTemporary() && "Expected temporary node");
796  N->replaceAllUsesWith(nullptr);
797  N->deleteAsSubclass();
798}
799
800void MDNode::storeDistinctInContext() {
801  assert(!Context.hasReplaceableUses() && "Unexpected replaceable uses");
802  assert(!NumUnresolved && "Unexpected unresolved nodes");
803  Storage = Distinct;
804  assert(isResolved() && "Expected this to be resolved");
805
806  // Reset the hash.
807  switch (getMetadataID()) {
808  default:
809    llvm_unreachable("Invalid subclass of MDNode");
810#define HANDLE_MDNODE_LEAF(CLASS)                                              \
811  case CLASS##Kind: {                                                          \
812    std::integral_constant<bool, HasCachedHash<CLASS>::value> ShouldResetHash; \
813    dispatchResetHash(cast<CLASS>(this), ShouldResetHash);                     \
814    break;                                                                     \
815  }
816#include "llvm/IR/Metadata.def"
817  }
818
819  getContext().pImpl->DistinctMDNodes.push_back(this);
820}
821
822void MDNode::replaceOperandWith(unsigned I, Metadata *New) {
823  if (getOperand(I) == New)
824    return;
825
826  if (!isUniqued()) {
827    setOperand(I, New);
828    return;
829  }
830
831  handleChangedOperand(mutable_begin() + I, New);
832}
833
834void MDNode::setOperand(unsigned I, Metadata *New) {
835  assert(I < NumOperands);
836  mutable_begin()[I].reset(New, isUniqued() ? this : nullptr);
837}
838
839/// Get a node or a self-reference that looks like it.
840///
841/// Special handling for finding self-references, for use by \a
842/// MDNode::concatenate() and \a MDNode::intersect() to maintain behaviour from
843/// when self-referencing nodes were still uniqued.  If the first operand has
844/// the same operands as \c Ops, return the first operand instead.
845static MDNode *getOrSelfReference(LLVMContext &Context,
846                                  ArrayRef<Metadata *> Ops) {
847  if (!Ops.empty())
848    if (MDNode *N = dyn_cast_or_null<MDNode>(Ops[0]))
849      if (N->getNumOperands() == Ops.size() && N == N->getOperand(0)) {
850        for (unsigned I = 1, E = Ops.size(); I != E; ++I)
851          if (Ops[I] != N->getOperand(I))
852            return MDNode::get(Context, Ops);
853        return N;
854      }
855
856  return MDNode::get(Context, Ops);
857}
858
859MDNode *MDNode::concatenate(MDNode *A, MDNode *B) {
860  if (!A)
861    return B;
862  if (!B)
863    return A;
864
865  SmallVector<Metadata *, 4> MDs;
866  MDs.reserve(A->getNumOperands() + B->getNumOperands());
867  MDs.append(A->op_begin(), A->op_end());
868  MDs.append(B->op_begin(), B->op_end());
869
870  // FIXME: This preserves long-standing behaviour, but is it really the right
871  // behaviour?  Or was that an unintended side-effect of node uniquing?
872  return getOrSelfReference(A->getContext(), MDs);
873}
874
875MDNode *MDNode::intersect(MDNode *A, MDNode *B) {
876  if (!A || !B)
877    return nullptr;
878
879  SmallVector<Metadata *, 4> MDs;
880  for (Metadata *MD : A->operands())
881    if (std::find(B->op_begin(), B->op_end(), MD) != B->op_end())
882      MDs.push_back(MD);
883
884  // FIXME: This preserves long-standing behaviour, but is it really the right
885  // behaviour?  Or was that an unintended side-effect of node uniquing?
886  return getOrSelfReference(A->getContext(), MDs);
887}
888
889MDNode *MDNode::getMostGenericAliasScope(MDNode *A, MDNode *B) {
890  if (!A || !B)
891    return nullptr;
892
893  SmallVector<Metadata *, 4> MDs(B->op_begin(), B->op_end());
894  for (Metadata *MD : A->operands())
895    if (std::find(B->op_begin(), B->op_end(), MD) == B->op_end())
896      MDs.push_back(MD);
897
898  // FIXME: This preserves long-standing behaviour, but is it really the right
899  // behaviour?  Or was that an unintended side-effect of node uniquing?
900  return getOrSelfReference(A->getContext(), MDs);
901}
902
903MDNode *MDNode::getMostGenericFPMath(MDNode *A, MDNode *B) {
904  if (!A || !B)
905    return nullptr;
906
907  APFloat AVal = mdconst::extract<ConstantFP>(A->getOperand(0))->getValueAPF();
908  APFloat BVal = mdconst::extract<ConstantFP>(B->getOperand(0))->getValueAPF();
909  if (AVal.compare(BVal) == APFloat::cmpLessThan)
910    return A;
911  return B;
912}
913
914static bool isContiguous(const ConstantRange &A, const ConstantRange &B) {
915  return A.getUpper() == B.getLower() || A.getLower() == B.getUpper();
916}
917
918static bool canBeMerged(const ConstantRange &A, const ConstantRange &B) {
919  return !A.intersectWith(B).isEmptySet() || isContiguous(A, B);
920}
921
922static bool tryMergeRange(SmallVectorImpl<ConstantInt *> &EndPoints,
923                          ConstantInt *Low, ConstantInt *High) {
924  ConstantRange NewRange(Low->getValue(), High->getValue());
925  unsigned Size = EndPoints.size();
926  APInt LB = EndPoints[Size - 2]->getValue();
927  APInt LE = EndPoints[Size - 1]->getValue();
928  ConstantRange LastRange(LB, LE);
929  if (canBeMerged(NewRange, LastRange)) {
930    ConstantRange Union = LastRange.unionWith(NewRange);
931    Type *Ty = High->getType();
932    EndPoints[Size - 2] =
933        cast<ConstantInt>(ConstantInt::get(Ty, Union.getLower()));
934    EndPoints[Size - 1] =
935        cast<ConstantInt>(ConstantInt::get(Ty, Union.getUpper()));
936    return true;
937  }
938  return false;
939}
940
941static void addRange(SmallVectorImpl<ConstantInt *> &EndPoints,
942                     ConstantInt *Low, ConstantInt *High) {
943  if (!EndPoints.empty())
944    if (tryMergeRange(EndPoints, Low, High))
945      return;
946
947  EndPoints.push_back(Low);
948  EndPoints.push_back(High);
949}
950
951MDNode *MDNode::getMostGenericRange(MDNode *A, MDNode *B) {
952  // Given two ranges, we want to compute the union of the ranges. This
953  // is slightly complitade by having to combine the intervals and merge
954  // the ones that overlap.
955
956  if (!A || !B)
957    return nullptr;
958
959  if (A == B)
960    return A;
961
962  // First, walk both lists in older of the lower boundary of each interval.
963  // At each step, try to merge the new interval to the last one we adedd.
964  SmallVector<ConstantInt *, 4> EndPoints;
965  int AI = 0;
966  int BI = 0;
967  int AN = A->getNumOperands() / 2;
968  int BN = B->getNumOperands() / 2;
969  while (AI < AN && BI < BN) {
970    ConstantInt *ALow = mdconst::extract<ConstantInt>(A->getOperand(2 * AI));
971    ConstantInt *BLow = mdconst::extract<ConstantInt>(B->getOperand(2 * BI));
972
973    if (ALow->getValue().slt(BLow->getValue())) {
974      addRange(EndPoints, ALow,
975               mdconst::extract<ConstantInt>(A->getOperand(2 * AI + 1)));
976      ++AI;
977    } else {
978      addRange(EndPoints, BLow,
979               mdconst::extract<ConstantInt>(B->getOperand(2 * BI + 1)));
980      ++BI;
981    }
982  }
983  while (AI < AN) {
984    addRange(EndPoints, mdconst::extract<ConstantInt>(A->getOperand(2 * AI)),
985             mdconst::extract<ConstantInt>(A->getOperand(2 * AI + 1)));
986    ++AI;
987  }
988  while (BI < BN) {
989    addRange(EndPoints, mdconst::extract<ConstantInt>(B->getOperand(2 * BI)),
990             mdconst::extract<ConstantInt>(B->getOperand(2 * BI + 1)));
991    ++BI;
992  }
993
994  // If we have more than 2 ranges (4 endpoints) we have to try to merge
995  // the last and first ones.
996  unsigned Size = EndPoints.size();
997  if (Size > 4) {
998    ConstantInt *FB = EndPoints[0];
999    ConstantInt *FE = EndPoints[1];
1000    if (tryMergeRange(EndPoints, FB, FE)) {
1001      for (unsigned i = 0; i < Size - 2; ++i) {
1002        EndPoints[i] = EndPoints[i + 2];
1003      }
1004      EndPoints.resize(Size - 2);
1005    }
1006  }
1007
1008  // If in the end we have a single range, it is possible that it is now the
1009  // full range. Just drop the metadata in that case.
1010  if (EndPoints.size() == 2) {
1011    ConstantRange Range(EndPoints[0]->getValue(), EndPoints[1]->getValue());
1012    if (Range.isFullSet())
1013      return nullptr;
1014  }
1015
1016  SmallVector<Metadata *, 4> MDs;
1017  MDs.reserve(EndPoints.size());
1018  for (auto *I : EndPoints)
1019    MDs.push_back(ConstantAsMetadata::get(I));
1020  return MDNode::get(A->getContext(), MDs);
1021}
1022
1023MDNode *MDNode::getMostGenericAlignmentOrDereferenceable(MDNode *A, MDNode *B) {
1024  if (!A || !B)
1025    return nullptr;
1026
1027  ConstantInt *AVal = mdconst::extract<ConstantInt>(A->getOperand(0));
1028  ConstantInt *BVal = mdconst::extract<ConstantInt>(B->getOperand(0));
1029  if (AVal->getZExtValue() < BVal->getZExtValue())
1030    return A;
1031  return B;
1032}
1033
1034//===----------------------------------------------------------------------===//
1035// NamedMDNode implementation.
1036//
1037
1038static SmallVector<TrackingMDRef, 4> &getNMDOps(void *Operands) {
1039  return *(SmallVector<TrackingMDRef, 4> *)Operands;
1040}
1041
1042NamedMDNode::NamedMDNode(const Twine &N)
1043    : Name(N.str()), Parent(nullptr),
1044      Operands(new SmallVector<TrackingMDRef, 4>()) {}
1045
1046NamedMDNode::~NamedMDNode() {
1047  dropAllReferences();
1048  delete &getNMDOps(Operands);
1049}
1050
1051unsigned NamedMDNode::getNumOperands() const {
1052  return (unsigned)getNMDOps(Operands).size();
1053}
1054
1055MDNode *NamedMDNode::getOperand(unsigned i) const {
1056  assert(i < getNumOperands() && "Invalid Operand number!");
1057  auto *N = getNMDOps(Operands)[i].get();
1058  return cast_or_null<MDNode>(N);
1059}
1060
1061void NamedMDNode::addOperand(MDNode *M) { getNMDOps(Operands).emplace_back(M); }
1062
1063void NamedMDNode::setOperand(unsigned I, MDNode *New) {
1064  assert(I < getNumOperands() && "Invalid operand number");
1065  getNMDOps(Operands)[I].reset(New);
1066}
1067
1068void NamedMDNode::eraseFromParent() {
1069  getParent()->eraseNamedMetadata(this);
1070}
1071
1072void NamedMDNode::dropAllReferences() {
1073  getNMDOps(Operands).clear();
1074}
1075
1076StringRef NamedMDNode::getName() const {
1077  return StringRef(Name);
1078}
1079
1080//===----------------------------------------------------------------------===//
1081// Instruction Metadata method implementations.
1082//
1083void MDAttachmentMap::set(unsigned ID, MDNode &MD) {
1084  for (auto &I : Attachments)
1085    if (I.first == ID) {
1086      I.second.reset(&MD);
1087      return;
1088    }
1089  Attachments.emplace_back(std::piecewise_construct, std::make_tuple(ID),
1090                           std::make_tuple(&MD));
1091}
1092
1093void MDAttachmentMap::erase(unsigned ID) {
1094  if (empty())
1095    return;
1096
1097  // Common case is one/last value.
1098  if (Attachments.back().first == ID) {
1099    Attachments.pop_back();
1100    return;
1101  }
1102
1103  for (auto I = Attachments.begin(), E = std::prev(Attachments.end()); I != E;
1104       ++I)
1105    if (I->first == ID) {
1106      *I = std::move(Attachments.back());
1107      Attachments.pop_back();
1108      return;
1109    }
1110}
1111
1112MDNode *MDAttachmentMap::lookup(unsigned ID) const {
1113  for (const auto &I : Attachments)
1114    if (I.first == ID)
1115      return I.second;
1116  return nullptr;
1117}
1118
1119void MDAttachmentMap::getAll(
1120    SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
1121  Result.append(Attachments.begin(), Attachments.end());
1122
1123  // Sort the resulting array so it is stable.
1124  if (Result.size() > 1)
1125    array_pod_sort(Result.begin(), Result.end());
1126}
1127
1128void MDGlobalAttachmentMap::insert(unsigned ID, MDNode &MD) {
1129  Attachments.push_back({ID, TrackingMDNodeRef(&MD)});
1130}
1131
1132void MDGlobalAttachmentMap::get(unsigned ID,
1133                                SmallVectorImpl<MDNode *> &Result) {
1134  for (auto A : Attachments)
1135    if (A.MDKind == ID)
1136      Result.push_back(A.Node);
1137}
1138
1139void MDGlobalAttachmentMap::erase(unsigned ID) {
1140  auto Follower = Attachments.begin();
1141  for (auto Leader = Attachments.begin(), E = Attachments.end(); Leader != E;
1142       ++Leader) {
1143    if (Leader->MDKind != ID) {
1144      if (Follower != Leader)
1145        *Follower = std::move(*Leader);
1146      ++Follower;
1147    }
1148  }
1149  Attachments.resize(Follower - Attachments.begin());
1150}
1151
1152void MDGlobalAttachmentMap::getAll(
1153    SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
1154  for (auto &A : Attachments)
1155    Result.emplace_back(A.MDKind, A.Node);
1156
1157  // Sort the resulting array so it is stable with respect to metadata IDs. We
1158  // need to preserve the original insertion order though.
1159  std::stable_sort(
1160      Result.begin(), Result.end(),
1161      [](const std::pair<unsigned, MDNode *> &A,
1162         const std::pair<unsigned, MDNode *> &B) { return A.first < B.first; });
1163}
1164
1165void Instruction::setMetadata(StringRef Kind, MDNode *Node) {
1166  if (!Node && !hasMetadata())
1167    return;
1168  setMetadata(getContext().getMDKindID(Kind), Node);
1169}
1170
1171MDNode *Instruction::getMetadataImpl(StringRef Kind) const {
1172  return getMetadataImpl(getContext().getMDKindID(Kind));
1173}
1174
1175void Instruction::dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs) {
1176  SmallSet<unsigned, 5> KnownSet;
1177  KnownSet.insert(KnownIDs.begin(), KnownIDs.end());
1178
1179  if (!hasMetadataHashEntry())
1180    return; // Nothing to remove!
1181
1182  auto &InstructionMetadata = getContext().pImpl->InstructionMetadata;
1183
1184  if (KnownSet.empty()) {
1185    // Just drop our entry at the store.
1186    InstructionMetadata.erase(this);
1187    setHasMetadataHashEntry(false);
1188    return;
1189  }
1190
1191  auto &Info = InstructionMetadata[this];
1192  Info.remove_if([&KnownSet](const std::pair<unsigned, TrackingMDNodeRef> &I) {
1193    return !KnownSet.count(I.first);
1194  });
1195
1196  if (Info.empty()) {
1197    // Drop our entry at the store.
1198    InstructionMetadata.erase(this);
1199    setHasMetadataHashEntry(false);
1200  }
1201}
1202
1203void Instruction::setMetadata(unsigned KindID, MDNode *Node) {
1204  if (!Node && !hasMetadata())
1205    return;
1206
1207  // Handle 'dbg' as a special case since it is not stored in the hash table.
1208  if (KindID == LLVMContext::MD_dbg) {
1209    DbgLoc = DebugLoc(Node);
1210    return;
1211  }
1212
1213  // Handle the case when we're adding/updating metadata on an instruction.
1214  if (Node) {
1215    auto &Info = getContext().pImpl->InstructionMetadata[this];
1216    assert(!Info.empty() == hasMetadataHashEntry() &&
1217           "HasMetadata bit is wonked");
1218    if (Info.empty())
1219      setHasMetadataHashEntry(true);
1220    Info.set(KindID, *Node);
1221    return;
1222  }
1223
1224  // Otherwise, we're removing metadata from an instruction.
1225  assert((hasMetadataHashEntry() ==
1226          (getContext().pImpl->InstructionMetadata.count(this) > 0)) &&
1227         "HasMetadata bit out of date!");
1228  if (!hasMetadataHashEntry())
1229    return;  // Nothing to remove!
1230  auto &Info = getContext().pImpl->InstructionMetadata[this];
1231
1232  // Handle removal of an existing value.
1233  Info.erase(KindID);
1234
1235  if (!Info.empty())
1236    return;
1237
1238  getContext().pImpl->InstructionMetadata.erase(this);
1239  setHasMetadataHashEntry(false);
1240}
1241
1242void Instruction::setAAMetadata(const AAMDNodes &N) {
1243  setMetadata(LLVMContext::MD_tbaa, N.TBAA);
1244  setMetadata(LLVMContext::MD_alias_scope, N.Scope);
1245  setMetadata(LLVMContext::MD_noalias, N.NoAlias);
1246}
1247
1248MDNode *Instruction::getMetadataImpl(unsigned KindID) const {
1249  // Handle 'dbg' as a special case since it is not stored in the hash table.
1250  if (KindID == LLVMContext::MD_dbg)
1251    return DbgLoc.getAsMDNode();
1252
1253  if (!hasMetadataHashEntry())
1254    return nullptr;
1255  auto &Info = getContext().pImpl->InstructionMetadata[this];
1256  assert(!Info.empty() && "bit out of sync with hash table");
1257
1258  return Info.lookup(KindID);
1259}
1260
1261void Instruction::getAllMetadataImpl(
1262    SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
1263  Result.clear();
1264
1265  // Handle 'dbg' as a special case since it is not stored in the hash table.
1266  if (DbgLoc) {
1267    Result.push_back(
1268        std::make_pair((unsigned)LLVMContext::MD_dbg, DbgLoc.getAsMDNode()));
1269    if (!hasMetadataHashEntry()) return;
1270  }
1271
1272  assert(hasMetadataHashEntry() &&
1273         getContext().pImpl->InstructionMetadata.count(this) &&
1274         "Shouldn't have called this");
1275  const auto &Info = getContext().pImpl->InstructionMetadata.find(this)->second;
1276  assert(!Info.empty() && "Shouldn't have called this");
1277  Info.getAll(Result);
1278}
1279
1280void Instruction::getAllMetadataOtherThanDebugLocImpl(
1281    SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
1282  Result.clear();
1283  assert(hasMetadataHashEntry() &&
1284         getContext().pImpl->InstructionMetadata.count(this) &&
1285         "Shouldn't have called this");
1286  const auto &Info = getContext().pImpl->InstructionMetadata.find(this)->second;
1287  assert(!Info.empty() && "Shouldn't have called this");
1288  Info.getAll(Result);
1289}
1290
1291bool Instruction::extractProfMetadata(uint64_t &TrueVal, uint64_t &FalseVal) {
1292  assert((getOpcode() == Instruction::Br ||
1293          getOpcode() == Instruction::Select) &&
1294         "Looking for branch weights on something besides branch or select");
1295
1296  auto *ProfileData = getMetadata(LLVMContext::MD_prof);
1297  if (!ProfileData || ProfileData->getNumOperands() != 3)
1298    return false;
1299
1300  auto *ProfDataName = dyn_cast<MDString>(ProfileData->getOperand(0));
1301  if (!ProfDataName || !ProfDataName->getString().equals("branch_weights"))
1302    return false;
1303
1304  auto *CITrue = mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(1));
1305  auto *CIFalse = mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(2));
1306  if (!CITrue || !CIFalse)
1307    return false;
1308
1309  TrueVal = CITrue->getValue().getZExtValue();
1310  FalseVal = CIFalse->getValue().getZExtValue();
1311
1312  return true;
1313}
1314
1315bool Instruction::extractProfTotalWeight(uint64_t &TotalVal) {
1316  assert((getOpcode() == Instruction::Br ||
1317          getOpcode() == Instruction::Select ||
1318          getOpcode() == Instruction::Call ||
1319          getOpcode() == Instruction::Invoke) &&
1320         "Looking for branch weights on something besides branch");
1321
1322  TotalVal = 0;
1323  auto *ProfileData = getMetadata(LLVMContext::MD_prof);
1324  if (!ProfileData)
1325    return false;
1326
1327  auto *ProfDataName = dyn_cast<MDString>(ProfileData->getOperand(0));
1328  if (!ProfDataName || !ProfDataName->getString().equals("branch_weights"))
1329    return false;
1330
1331  TotalVal = 0;
1332  for (unsigned i = 1; i < ProfileData->getNumOperands(); i++) {
1333    auto *V = mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(i));
1334    if (!V)
1335      return false;
1336    TotalVal += V->getValue().getZExtValue();
1337  }
1338  return true;
1339}
1340
1341void Instruction::clearMetadataHashEntries() {
1342  assert(hasMetadataHashEntry() && "Caller should check");
1343  getContext().pImpl->InstructionMetadata.erase(this);
1344  setHasMetadataHashEntry(false);
1345}
1346
1347void GlobalObject::getMetadata(unsigned KindID,
1348                               SmallVectorImpl<MDNode *> &MDs) const {
1349  if (hasMetadata())
1350    getContext().pImpl->GlobalObjectMetadata[this].get(KindID, MDs);
1351}
1352
1353void GlobalObject::getMetadata(StringRef Kind,
1354                               SmallVectorImpl<MDNode *> &MDs) const {
1355  if (hasMetadata())
1356    getMetadata(getContext().getMDKindID(Kind), MDs);
1357}
1358
1359void GlobalObject::addMetadata(unsigned KindID, MDNode &MD) {
1360  if (!hasMetadata())
1361    setHasMetadataHashEntry(true);
1362
1363  getContext().pImpl->GlobalObjectMetadata[this].insert(KindID, MD);
1364}
1365
1366void GlobalObject::addMetadata(StringRef Kind, MDNode &MD) {
1367  addMetadata(getContext().getMDKindID(Kind), MD);
1368}
1369
1370void GlobalObject::eraseMetadata(unsigned KindID) {
1371  // Nothing to unset.
1372  if (!hasMetadata())
1373    return;
1374
1375  auto &Store = getContext().pImpl->GlobalObjectMetadata[this];
1376  Store.erase(KindID);
1377  if (Store.empty())
1378    clearMetadata();
1379}
1380
1381void GlobalObject::getAllMetadata(
1382    SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
1383  MDs.clear();
1384
1385  if (!hasMetadata())
1386    return;
1387
1388  getContext().pImpl->GlobalObjectMetadata[this].getAll(MDs);
1389}
1390
1391void GlobalObject::clearMetadata() {
1392  if (!hasMetadata())
1393    return;
1394  getContext().pImpl->GlobalObjectMetadata.erase(this);
1395  setHasMetadataHashEntry(false);
1396}
1397
1398void GlobalObject::setMetadata(unsigned KindID, MDNode *N) {
1399  eraseMetadata(KindID);
1400  if (N)
1401    addMetadata(KindID, *N);
1402}
1403
1404void GlobalObject::setMetadata(StringRef Kind, MDNode *N) {
1405  setMetadata(getContext().getMDKindID(Kind), N);
1406}
1407
1408MDNode *GlobalObject::getMetadata(unsigned KindID) const {
1409  SmallVector<MDNode *, 1> MDs;
1410  getMetadata(KindID, MDs);
1411  assert(MDs.size() <= 1 && "Expected at most one metadata attachment");
1412  if (MDs.empty())
1413    return nullptr;
1414  return MDs[0];
1415}
1416
1417MDNode *GlobalObject::getMetadata(StringRef Kind) const {
1418  return getMetadata(getContext().getMDKindID(Kind));
1419}
1420
1421void GlobalObject::copyMetadata(const GlobalObject *Other, unsigned Offset) {
1422  SmallVector<std::pair<unsigned, MDNode *>, 8> MDs;
1423  Other->getAllMetadata(MDs);
1424  for (auto &MD : MDs) {
1425    // We need to adjust the type metadata offset.
1426    if (Offset != 0 && MD.first == LLVMContext::MD_type) {
1427      auto *OffsetConst = cast<ConstantInt>(
1428          cast<ConstantAsMetadata>(MD.second->getOperand(0))->getValue());
1429      Metadata *TypeId = MD.second->getOperand(1);
1430      auto *NewOffsetMD = ConstantAsMetadata::get(ConstantInt::get(
1431          OffsetConst->getType(), OffsetConst->getValue() + Offset));
1432      addMetadata(LLVMContext::MD_type,
1433                  *MDNode::get(getContext(), {NewOffsetMD, TypeId}));
1434      continue;
1435    }
1436    addMetadata(MD.first, *MD.second);
1437  }
1438}
1439
1440void GlobalObject::addTypeMetadata(unsigned Offset, Metadata *TypeID) {
1441  addMetadata(
1442      LLVMContext::MD_type,
1443      *MDTuple::get(getContext(),
1444                    {llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1445                         Type::getInt64Ty(getContext()), Offset)),
1446                     TypeID}));
1447}
1448
1449void Function::setSubprogram(DISubprogram *SP) {
1450  setMetadata(LLVMContext::MD_dbg, SP);
1451}
1452
1453DISubprogram *Function::getSubprogram() const {
1454  return cast_or_null<DISubprogram>(getMetadata(LLVMContext::MD_dbg));
1455}
1456