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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 
28 using namespace llvm;
29 
MetadataAsValue(Type * Ty,Metadata * MD)30 MetadataAsValue::MetadataAsValue(Type *Ty, Metadata *MD)
31     : Value(Ty, MetadataAsValueVal), MD(MD) {
32   track();
33 }
34 
~MetadataAsValue()35 MetadataAsValue::~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.
canonicalizeMetadataForValue(LLVMContext & Context,Metadata * MD)51 static 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 
get(LLVMContext & Context,Metadata * MD)73 MetadataAsValue *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 
getIfExists(LLVMContext & Context,Metadata * MD)81 MetadataAsValue *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 
handleChangedMetadata(Metadata * MD)88 void 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 
track()111 void MetadataAsValue::track() {
112   if (MD)
113     MetadataTracking::track(&MD, *MD, *this);
114 }
115 
untrack()116 void MetadataAsValue::untrack() {
117   if (MD)
118     MetadataTracking::untrack(MD);
119 }
120 
track(void * Ref,Metadata & MD,OwnerTy Owner)121 bool 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 
untrack(void * Ref,Metadata & MD)138 void 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 
retrack(void * Ref,Metadata & MD,void * New)146 bool 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 
isReplaceable(const Metadata & MD)161 bool MetadataTracking::isReplaceable(const Metadata &MD) {
162   return ReplaceableMetadataImpl::isReplaceable(MD);
163 }
164 
addRef(void * Ref,OwnerTy Owner)165 void 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 
dropRef(void * Ref)176 void ReplaceableMetadataImpl::dropRef(void *Ref) {
177   bool WasErased = UseMap.erase(Ref);
178   (void)WasErased;
179   assert(WasErased && "Expected to drop a reference");
180 }
181 
moveRef(void * Ref,void * New,const Metadata & MD)182 void 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 
replaceAllUsesWith(Metadata * MD)200 void 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 
resolveAllUses(bool ResolveUsers)248 void 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 
getOrCreate(Metadata & MD)281 ReplaceableMetadataImpl *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 
getIfExists(Metadata & MD)287 ReplaceableMetadataImpl *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 
isReplaceable(const Metadata & MD)293 bool 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 
getLocalFunction(Value * V)299 static 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 
get(Value * V)308 ValueAsMetadata *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 
getIfExists(Value * V)328 ValueAsMetadata *ValueAsMetadata::getIfExists(Value *V) {
329   assert(V && "Unexpected null Value");
330   return V->getContext().pImpl->ValuesAsMetadata.lookup(V);
331 }
332 
handleDeletion(Value * V)333 void 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 
handleRAUW(Value * From,Value * To)352 void 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 
get(LLVMContext & Context,StringRef Str)417 MDString *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 
getString() const427 StringRef 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 
operator new(size_t Size,unsigned NumOps)444 void *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 
operator delete(void * Mem)456 void 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 
MDNode(LLVMContext & Context,unsigned ID,StorageType Storage,ArrayRef<Metadata * > Ops1,ArrayRef<Metadata * > Ops2)467 MDNode::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 
clone() const485 TempMDNode 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 
isOperandUnresolved(Metadata * Op)496 static bool isOperandUnresolved(Metadata *Op) {
497   if (auto *N = dyn_cast_or_null<MDNode>(Op))
498     return !N->isResolved();
499   return false;
500 }
501 
countUnresolvedOperands()502 void 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 
makeUniqued()508 void 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 
makeDistinct()527 void 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 
resolve()539 void 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 
dropReplaceableUses()549 void MDNode::dropReplaceableUses() {
550   assert(!NumUnresolved && "Unexpected unresolved operand");
551 
552   // Drop any RAUW support.
553   if (Context.hasReplaceableUses())
554     Context.takeReplaceableUses()->resolveAllUses();
555 }
556 
resolveAfterOperandChange(Metadata * Old,Metadata * New)557 void 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 
decrementUnresolvedOperandCount()570 void 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 
resolveCycles()584 void 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 
hasSelfReference(MDNode * N)604 static bool hasSelfReference(MDNode *N) {
605   for (Metadata *MD : N->operands())
606     if (MD == N)
607       return true;
608   return false;
609 }
610 
replaceWithPermanentImpl()611 MDNode *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 
replaceWithUniquedImpl()629 MDNode *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 
replaceWithDistinctImpl()644 MDNode *MDNode::replaceWithDistinctImpl() {
645   makeDistinct();
646   return this;
647 }
648 
recalculateHash()649 void MDTuple::recalculateHash() {
650   setHash(MDTupleInfo::KeyTy::calculateHash(this));
651 }
652 
dropAllReferences()653 void 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 
handleChangedOperand(void * Ref,Metadata * New)662 void 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 
deleteAsSubclass()712 void 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 
724 template <class T, class InfoT>
uniquifyImpl(T * N,DenseSet<T *,InfoT> & Store)725 static 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 
733 template <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 
uniquify()745 MDNode *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 
eraseFromStore()764 void 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 
getImpl(LLVMContext & Context,ArrayRef<Metadata * > MDs,StorageType Storage,bool ShouldCreate)776 MDTuple *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 
deleteTemporary(MDNode * N)794 void MDNode::deleteTemporary(MDNode *N) {
795   assert(N->isTemporary() && "Expected temporary node");
796   N->replaceAllUsesWith(nullptr);
797   N->deleteAsSubclass();
798 }
799 
storeDistinctInContext()800 void 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 
replaceOperandWith(unsigned I,Metadata * New)822 void 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 
setOperand(unsigned I,Metadata * New)834 void 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.
getOrSelfReference(LLVMContext & Context,ArrayRef<Metadata * > Ops)845 static 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 
concatenate(MDNode * A,MDNode * B)859 MDNode *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 
intersect(MDNode * A,MDNode * B)875 MDNode *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 
getMostGenericAliasScope(MDNode * A,MDNode * B)889 MDNode *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 
getMostGenericFPMath(MDNode * A,MDNode * B)903 MDNode *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 
isContiguous(const ConstantRange & A,const ConstantRange & B)914 static bool isContiguous(const ConstantRange &A, const ConstantRange &B) {
915   return A.getUpper() == B.getLower() || A.getLower() == B.getUpper();
916 }
917 
canBeMerged(const ConstantRange & A,const ConstantRange & B)918 static bool canBeMerged(const ConstantRange &A, const ConstantRange &B) {
919   return !A.intersectWith(B).isEmptySet() || isContiguous(A, B);
920 }
921 
tryMergeRange(SmallVectorImpl<ConstantInt * > & EndPoints,ConstantInt * Low,ConstantInt * High)922 static 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 
addRange(SmallVectorImpl<ConstantInt * > & EndPoints,ConstantInt * Low,ConstantInt * High)941 static 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 
getMostGenericRange(MDNode * A,MDNode * B)951 MDNode *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 
getMostGenericAlignmentOrDereferenceable(MDNode * A,MDNode * B)1023 MDNode *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 
getNMDOps(void * Operands)1038 static SmallVector<TrackingMDRef, 4> &getNMDOps(void *Operands) {
1039   return *(SmallVector<TrackingMDRef, 4> *)Operands;
1040 }
1041 
NamedMDNode(const Twine & N)1042 NamedMDNode::NamedMDNode(const Twine &N)
1043     : Name(N.str()), Parent(nullptr),
1044       Operands(new SmallVector<TrackingMDRef, 4>()) {}
1045 
~NamedMDNode()1046 NamedMDNode::~NamedMDNode() {
1047   dropAllReferences();
1048   delete &getNMDOps(Operands);
1049 }
1050 
getNumOperands() const1051 unsigned NamedMDNode::getNumOperands() const {
1052   return (unsigned)getNMDOps(Operands).size();
1053 }
1054 
getOperand(unsigned i) const1055 MDNode *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 
addOperand(MDNode * M)1061 void NamedMDNode::addOperand(MDNode *M) { getNMDOps(Operands).emplace_back(M); }
1062 
setOperand(unsigned I,MDNode * New)1063 void NamedMDNode::setOperand(unsigned I, MDNode *New) {
1064   assert(I < getNumOperands() && "Invalid operand number");
1065   getNMDOps(Operands)[I].reset(New);
1066 }
1067 
eraseFromParent()1068 void NamedMDNode::eraseFromParent() {
1069   getParent()->eraseNamedMetadata(this);
1070 }
1071 
dropAllReferences()1072 void NamedMDNode::dropAllReferences() {
1073   getNMDOps(Operands).clear();
1074 }
1075 
getName() const1076 StringRef NamedMDNode::getName() const {
1077   return StringRef(Name);
1078 }
1079 
1080 //===----------------------------------------------------------------------===//
1081 // Instruction Metadata method implementations.
1082 //
set(unsigned ID,MDNode & MD)1083 void 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 
erase(unsigned ID)1093 void 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 
lookup(unsigned ID) const1112 MDNode *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 
getAll(SmallVectorImpl<std::pair<unsigned,MDNode * >> & Result) const1119 void 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 
insert(unsigned ID,MDNode & MD)1128 void MDGlobalAttachmentMap::insert(unsigned ID, MDNode &MD) {
1129   Attachments.push_back({ID, TrackingMDNodeRef(&MD)});
1130 }
1131 
get(unsigned ID,SmallVectorImpl<MDNode * > & Result)1132 void 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 
erase(unsigned ID)1139 void 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 
getAll(SmallVectorImpl<std::pair<unsigned,MDNode * >> & Result) const1152 void 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 
setMetadata(StringRef Kind,MDNode * Node)1165 void Instruction::setMetadata(StringRef Kind, MDNode *Node) {
1166   if (!Node && !hasMetadata())
1167     return;
1168   setMetadata(getContext().getMDKindID(Kind), Node);
1169 }
1170 
getMetadataImpl(StringRef Kind) const1171 MDNode *Instruction::getMetadataImpl(StringRef Kind) const {
1172   return getMetadataImpl(getContext().getMDKindID(Kind));
1173 }
1174 
dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs)1175 void 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 
setMetadata(unsigned KindID,MDNode * Node)1203 void 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 
setAAMetadata(const AAMDNodes & N)1242 void 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 
getMetadataImpl(unsigned KindID) const1248 MDNode *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 
getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned,MDNode * >> & Result) const1261 void 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 
getAllMetadataOtherThanDebugLocImpl(SmallVectorImpl<std::pair<unsigned,MDNode * >> & Result) const1280 void 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 
extractProfMetadata(uint64_t & TrueVal,uint64_t & FalseVal)1291 bool 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 
extractProfTotalWeight(uint64_t & TotalVal)1315 bool 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 
clearMetadataHashEntries()1341 void Instruction::clearMetadataHashEntries() {
1342   assert(hasMetadataHashEntry() && "Caller should check");
1343   getContext().pImpl->InstructionMetadata.erase(this);
1344   setHasMetadataHashEntry(false);
1345 }
1346 
getMetadata(unsigned KindID,SmallVectorImpl<MDNode * > & MDs) const1347 void GlobalObject::getMetadata(unsigned KindID,
1348                                SmallVectorImpl<MDNode *> &MDs) const {
1349   if (hasMetadata())
1350     getContext().pImpl->GlobalObjectMetadata[this].get(KindID, MDs);
1351 }
1352 
getMetadata(StringRef Kind,SmallVectorImpl<MDNode * > & MDs) const1353 void GlobalObject::getMetadata(StringRef Kind,
1354                                SmallVectorImpl<MDNode *> &MDs) const {
1355   if (hasMetadata())
1356     getMetadata(getContext().getMDKindID(Kind), MDs);
1357 }
1358 
addMetadata(unsigned KindID,MDNode & MD)1359 void GlobalObject::addMetadata(unsigned KindID, MDNode &MD) {
1360   if (!hasMetadata())
1361     setHasMetadataHashEntry(true);
1362 
1363   getContext().pImpl->GlobalObjectMetadata[this].insert(KindID, MD);
1364 }
1365 
addMetadata(StringRef Kind,MDNode & MD)1366 void GlobalObject::addMetadata(StringRef Kind, MDNode &MD) {
1367   addMetadata(getContext().getMDKindID(Kind), MD);
1368 }
1369 
eraseMetadata(unsigned KindID)1370 void 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 
getAllMetadata(SmallVectorImpl<std::pair<unsigned,MDNode * >> & MDs) const1381 void 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 
clearMetadata()1391 void GlobalObject::clearMetadata() {
1392   if (!hasMetadata())
1393     return;
1394   getContext().pImpl->GlobalObjectMetadata.erase(this);
1395   setHasMetadataHashEntry(false);
1396 }
1397 
setMetadata(unsigned KindID,MDNode * N)1398 void GlobalObject::setMetadata(unsigned KindID, MDNode *N) {
1399   eraseMetadata(KindID);
1400   if (N)
1401     addMetadata(KindID, *N);
1402 }
1403 
setMetadata(StringRef Kind,MDNode * N)1404 void GlobalObject::setMetadata(StringRef Kind, MDNode *N) {
1405   setMetadata(getContext().getMDKindID(Kind), N);
1406 }
1407 
getMetadata(unsigned KindID) const1408 MDNode *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 
getMetadata(StringRef Kind) const1417 MDNode *GlobalObject::getMetadata(StringRef Kind) const {
1418   return getMetadata(getContext().getMDKindID(Kind));
1419 }
1420 
copyMetadata(const GlobalObject * Other,unsigned Offset)1421 void 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 
addTypeMetadata(unsigned Offset,Metadata * TypeID)1440 void 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 
setSubprogram(DISubprogram * SP)1449 void Function::setSubprogram(DISubprogram *SP) {
1450   setMetadata(LLVMContext::MD_dbg, SP);
1451 }
1452 
getSubprogram() const1453 DISubprogram *Function::getSubprogram() const {
1454   return cast_or_null<DISubprogram>(getMetadata(LLVMContext::MD_dbg));
1455 }
1456