1 //===-- Metadata.cpp - Implement Metadata classes -------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the Metadata classes.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/IR/Metadata.h"
15 #include "LLVMContextImpl.h"
16 #include "SymbolTableListTraitsImpl.h"
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/ADT/SmallSet.h"
20 #include "llvm/ADT/SmallString.h"
21 #include "llvm/ADT/StringMap.h"
22 #include "llvm/IR/ConstantRange.h"
23 #include "llvm/IR/Instruction.h"
24 #include "llvm/IR/LLVMContext.h"
25 #include "llvm/IR/LeakDetector.h"
26 #include "llvm/IR/Module.h"
27 #include "llvm/IR/ValueHandle.h"
31 Metadata::Metadata(LLVMContext &Context, unsigned ID)
32 : Value(Type::getMetadataTy(Context), ID) {}
34 //===----------------------------------------------------------------------===//
35 // MDString implementation.
38 void MDString::anchor() { }
40 MDString *MDString::get(LLVMContext &Context, StringRef Str) {
41 auto &Store = Context.pImpl->MDStringCache;
42 auto I = Store.find(Str);
47 StringMapEntry<MDString>::Create(Str, Store.getAllocator(), Context);
48 bool WasInserted = Store.insert(Entry);
50 assert(WasInserted && "Expected entry to be inserted");
51 Entry->second.Entry = Entry;
52 return &Entry->second;
55 StringRef MDString::getString() const {
56 assert(Entry && "Expected to find string map entry");
57 return Entry->first();
60 //===----------------------------------------------------------------------===//
61 // MDNodeOperand implementation.
64 // Use CallbackVH to hold MDNode operands.
66 class MDNodeOperand : public CallbackVH {
68 MDNodeOperand *Cur = this;
70 while (Cur->getValPtrInt() != 1)
73 assert(Cur->getValPtrInt() == 1 &&
74 "Couldn't find the end of the operand list!");
75 return reinterpret_cast<MDNode *>(Cur + 1);
80 virtual ~MDNodeOperand();
83 unsigned IsLast = this->getValPtrInt();
85 this->setAsLastOperand(IsLast);
88 /// \brief Accessor method to mark the operand as the first in the list.
89 void setAsLastOperand(unsigned I) { this->setValPtrInt(I); }
91 void deleted() override;
92 void allUsesReplacedWith(Value *NV) override;
94 } // end namespace llvm.
96 // Provide out-of-line definition to prevent weak vtable.
97 MDNodeOperand::~MDNodeOperand() {}
99 void MDNodeOperand::deleted() {
100 getParent()->replaceOperand(this, nullptr);
103 void MDNodeOperand::allUsesReplacedWith(Value *NV) {
104 getParent()->replaceOperand(this, NV);
107 //===----------------------------------------------------------------------===//
108 // MDNode implementation.
111 /// \brief Get the MDNodeOperand's coallocated on the end of the MDNode.
112 static MDNodeOperand *getOperandPtr(MDNode *N, unsigned Op) {
113 // Use <= instead of < to permit a one-past-the-end address.
114 assert(Op <= N->getNumOperands() && "Invalid operand number");
115 return reinterpret_cast<MDNodeOperand *>(N) - N->getNumOperands() + Op;
118 void MDNode::replaceOperandWith(unsigned i, Value *Val) {
119 MDNodeOperand *Op = getOperandPtr(this, i);
120 replaceOperand(Op, Val);
123 void *MDNode::operator new(size_t Size, unsigned NumOps) {
124 void *Ptr = ::operator new(Size + NumOps * sizeof(MDNodeOperand));
125 MDNodeOperand *Op = static_cast<MDNodeOperand *>(Ptr);
127 MDNodeOperand *Last = Op + NumOps;
128 for (; Op != Last; ++Op)
129 new (Op) MDNodeOperand();
130 (Op - 1)->setAsLastOperand(1);
135 void MDNode::operator delete(void *Mem) {
136 MDNode *N = static_cast<MDNode *>(Mem);
137 MDNodeOperand *Op = static_cast<MDNodeOperand *>(Mem);
138 for (unsigned I = 0, E = N->NumOperands; I != E; ++I)
139 (--Op)->~MDNodeOperand();
140 ::operator delete(Op);
143 MDNode::MDNode(LLVMContext &C, unsigned ID, ArrayRef<Value *> Vals,
144 bool isFunctionLocal)
146 NumOperands = Vals.size();
149 setValueSubclassData(getSubclassDataFromValue() | FunctionLocalBit);
151 // Initialize the operand list.
153 for (MDNodeOperand *Op = getOperandPtr(this, 0), *E = Op + NumOperands;
158 GenericMDNode::~GenericMDNode() {
159 LLVMContextImpl *pImpl = getType()->getContext().pImpl;
160 if (isNotUniqued()) {
161 pImpl->NonUniquedMDNodes.erase(this);
163 pImpl->MDNodeSet.erase(this);
167 void GenericMDNode::dropAllReferences() {
168 for (MDNodeOperand *Op = getOperandPtr(this, 0), *E = Op + NumOperands;
173 static const Function *getFunctionForValue(Value *V) {
174 if (!V) return nullptr;
175 if (Instruction *I = dyn_cast<Instruction>(V)) {
176 BasicBlock *BB = I->getParent();
177 return BB ? BB->getParent() : nullptr;
179 if (Argument *A = dyn_cast<Argument>(V))
180 return A->getParent();
181 if (BasicBlock *BB = dyn_cast<BasicBlock>(V))
182 return BB->getParent();
183 if (MDNode *MD = dyn_cast<MDNode>(V))
184 return MD->getFunction();
189 static const Function *assertLocalFunction(const MDNode *N) {
190 if (!N->isFunctionLocal()) return nullptr;
192 // FIXME: This does not handle cyclic function local metadata.
193 const Function *F = nullptr, *NewF = nullptr;
194 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
195 if (Value *V = N->getOperand(i)) {
196 if (MDNode *MD = dyn_cast<MDNode>(V))
197 NewF = assertLocalFunction(MD);
199 NewF = getFunctionForValue(V);
204 assert((NewF == nullptr || F == NewF) &&
205 "inconsistent function-local metadata");
211 // getFunction - If this metadata is function-local and recursively has a
212 // function-local operand, return the first such operand's parent function.
213 // Otherwise, return null. getFunction() should not be used for performance-
214 // critical code because it recursively visits all the MDNode's operands.
215 const Function *MDNode::getFunction() const {
217 return assertLocalFunction(this);
219 if (!isFunctionLocal()) return nullptr;
220 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
221 if (const Function *F = getFunctionForValue(getOperand(i)))
227 /// \brief Check if the Value would require a function-local MDNode.
228 static bool isFunctionLocalValue(Value *V) {
229 return isa<Instruction>(V) || isa<Argument>(V) || isa<BasicBlock>(V) ||
230 (isa<MDNode>(V) && cast<MDNode>(V)->isFunctionLocal());
233 MDNode *MDNode::getMDNode(LLVMContext &Context, ArrayRef<Value*> Vals,
234 FunctionLocalness FL, bool Insert) {
235 auto &Store = Context.pImpl->MDNodeSet;
237 GenericMDNodeInfo::KeyTy Key(Vals);
238 auto I = Store.find_as(Key);
239 if (I != Store.end())
244 bool isFunctionLocal = false;
247 for (Value *V : Vals) {
249 if (isFunctionLocalValue(V)) {
250 isFunctionLocal = true;
256 isFunctionLocal = false;
259 isFunctionLocal = true;
263 // Coallocate space for the node and Operands together, then placement new.
265 new (Vals.size()) GenericMDNode(Context, Vals, isFunctionLocal);
272 MDNode *MDNode::get(LLVMContext &Context, ArrayRef<Value*> Vals) {
273 return getMDNode(Context, Vals, FL_Unknown);
276 MDNode *MDNode::getWhenValsUnresolved(LLVMContext &Context,
277 ArrayRef<Value*> Vals,
278 bool isFunctionLocal) {
279 return getMDNode(Context, Vals, isFunctionLocal ? FL_Yes : FL_No);
282 MDNode *MDNode::getIfExists(LLVMContext &Context, ArrayRef<Value*> Vals) {
283 return getMDNode(Context, Vals, FL_Unknown, false);
286 MDNode *MDNode::getTemporary(LLVMContext &Context, ArrayRef<Value*> Vals) {
287 MDNode *N = new (Vals.size()) MDNodeFwdDecl(Context, Vals, FL_No);
288 N->setValueSubclassData(N->getSubclassDataFromValue() | NotUniquedBit);
289 LeakDetector::addGarbageObject(N);
293 void MDNode::deleteTemporary(MDNode *N) {
294 assert(N->use_empty() && "Temporary MDNode has uses!");
295 assert(isa<MDNodeFwdDecl>(N) && "Expected forward declaration");
296 assert((N->getSubclassDataFromValue() & NotUniquedBit) &&
297 "Temporary MDNode does not have NotUniquedBit set!");
298 LeakDetector::removeGarbageObject(N);
299 delete cast<MDNodeFwdDecl>(N);
302 /// \brief Return specified operand.
303 Value *MDNode::getOperand(unsigned i) const {
304 assert(i < getNumOperands() && "Invalid operand number");
305 return *getOperandPtr(const_cast<MDNode*>(this), i);
308 void MDNode::setIsNotUniqued() {
309 setValueSubclassData(getSubclassDataFromValue() | NotUniquedBit);
310 LLVMContextImpl *pImpl = getType()->getContext().pImpl;
311 auto *G = cast<GenericMDNode>(this);
313 pImpl->NonUniquedMDNodes.insert(G);
316 // Replace value from this node's operand list.
317 void MDNode::replaceOperand(MDNodeOperand *Op, Value *To) {
320 // If is possible that someone did GV->RAUW(inst), replacing a global variable
321 // with an instruction or some other function-local object. If this is a
322 // non-function-local MDNode, it can't point to a function-local object.
323 // Handle this case by implicitly dropping the MDNode reference to null.
324 // Likewise if the MDNode is function-local but for a different function.
325 if (To && isFunctionLocalValue(To)) {
326 if (!isFunctionLocal())
329 const Function *F = getFunction();
330 const Function *FV = getFunctionForValue(To);
331 // Metadata can be function-local without having an associated function.
332 // So only consider functions to have changed if non-null.
333 if (F && FV && F != FV)
341 // If this node is already not being uniqued (because one of the operands
342 // already went to null), then there is nothing else to do here.
343 if (isNotUniqued()) {
348 auto &Store = getContext().pImpl->MDNodeSet;
349 auto *N = cast<GenericMDNode>(this);
351 // Remove "this" from the context map.
354 // Update the operand.
357 // If we are dropping an argument to null, we choose to not unique the MDNode
358 // anymore. This commonly occurs during destruction, and uniquing these
359 // brings little reuse. Also, this means we don't need to include
360 // isFunctionLocal bits in the hash for MDNodes.
366 // Now that the node is out of the table, get ready to reinsert it. First,
367 // check to see if another node with the same operands already exists in the
368 // set. If so, then this node is redundant.
369 SmallVector<Value *, 8> Vals;
370 GenericMDNodeInfo::KeyTy Key(N, Vals);
371 auto I = Store.find_as(Key);
372 if (I != Store.end()) {
373 N->replaceAllUsesWith(*I);
381 // If this MDValue was previously function-local but no longer is, clear
382 // its function-local flag.
383 if (isFunctionLocal() && !isFunctionLocalValue(To)) {
384 bool isStillFunctionLocal = false;
385 for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
386 Value *V = getOperand(i);
388 if (isFunctionLocalValue(V)) {
389 isStillFunctionLocal = true;
393 if (!isStillFunctionLocal)
394 setValueSubclassData(getSubclassDataFromValue() & ~FunctionLocalBit);
398 MDNode *MDNode::concatenate(MDNode *A, MDNode *B) {
404 SmallVector<Value *, 4> Vals(A->getNumOperands() +
405 B->getNumOperands());
408 for (unsigned i = 0, ie = A->getNumOperands(); i != ie; ++i)
409 Vals[j++] = A->getOperand(i);
410 for (unsigned i = 0, ie = B->getNumOperands(); i != ie; ++i)
411 Vals[j++] = B->getOperand(i);
413 return MDNode::get(A->getContext(), Vals);
416 MDNode *MDNode::intersect(MDNode *A, MDNode *B) {
420 SmallVector<Value *, 4> Vals;
421 for (unsigned i = 0, ie = A->getNumOperands(); i != ie; ++i) {
422 Value *V = A->getOperand(i);
423 for (unsigned j = 0, je = B->getNumOperands(); j != je; ++j)
424 if (V == B->getOperand(j)) {
430 return MDNode::get(A->getContext(), Vals);
433 MDNode *MDNode::getMostGenericFPMath(MDNode *A, MDNode *B) {
437 APFloat AVal = cast<ConstantFP>(A->getOperand(0))->getValueAPF();
438 APFloat BVal = cast<ConstantFP>(B->getOperand(0))->getValueAPF();
439 if (AVal.compare(BVal) == APFloat::cmpLessThan)
444 static bool isContiguous(const ConstantRange &A, const ConstantRange &B) {
445 return A.getUpper() == B.getLower() || A.getLower() == B.getUpper();
448 static bool canBeMerged(const ConstantRange &A, const ConstantRange &B) {
449 return !A.intersectWith(B).isEmptySet() || isContiguous(A, B);
452 static bool tryMergeRange(SmallVectorImpl<Value *> &EndPoints, ConstantInt *Low,
454 ConstantRange NewRange(Low->getValue(), High->getValue());
455 unsigned Size = EndPoints.size();
456 APInt LB = cast<ConstantInt>(EndPoints[Size - 2])->getValue();
457 APInt LE = cast<ConstantInt>(EndPoints[Size - 1])->getValue();
458 ConstantRange LastRange(LB, LE);
459 if (canBeMerged(NewRange, LastRange)) {
460 ConstantRange Union = LastRange.unionWith(NewRange);
461 Type *Ty = High->getType();
462 EndPoints[Size - 2] = ConstantInt::get(Ty, Union.getLower());
463 EndPoints[Size - 1] = ConstantInt::get(Ty, Union.getUpper());
469 static void addRange(SmallVectorImpl<Value *> &EndPoints, ConstantInt *Low,
471 if (!EndPoints.empty())
472 if (tryMergeRange(EndPoints, Low, High))
475 EndPoints.push_back(Low);
476 EndPoints.push_back(High);
479 MDNode *MDNode::getMostGenericRange(MDNode *A, MDNode *B) {
480 // Given two ranges, we want to compute the union of the ranges. This
481 // is slightly complitade by having to combine the intervals and merge
482 // the ones that overlap.
490 // First, walk both lists in older of the lower boundary of each interval.
491 // At each step, try to merge the new interval to the last one we adedd.
492 SmallVector<Value*, 4> EndPoints;
495 int AN = A->getNumOperands() / 2;
496 int BN = B->getNumOperands() / 2;
497 while (AI < AN && BI < BN) {
498 ConstantInt *ALow = cast<ConstantInt>(A->getOperand(2 * AI));
499 ConstantInt *BLow = cast<ConstantInt>(B->getOperand(2 * BI));
501 if (ALow->getValue().slt(BLow->getValue())) {
502 addRange(EndPoints, ALow, cast<ConstantInt>(A->getOperand(2 * AI + 1)));
505 addRange(EndPoints, BLow, cast<ConstantInt>(B->getOperand(2 * BI + 1)));
510 addRange(EndPoints, cast<ConstantInt>(A->getOperand(2 * AI)),
511 cast<ConstantInt>(A->getOperand(2 * AI + 1)));
515 addRange(EndPoints, cast<ConstantInt>(B->getOperand(2 * BI)),
516 cast<ConstantInt>(B->getOperand(2 * BI + 1)));
520 // If we have more than 2 ranges (4 endpoints) we have to try to merge
521 // the last and first ones.
522 unsigned Size = EndPoints.size();
524 ConstantInt *FB = cast<ConstantInt>(EndPoints[0]);
525 ConstantInt *FE = cast<ConstantInt>(EndPoints[1]);
526 if (tryMergeRange(EndPoints, FB, FE)) {
527 for (unsigned i = 0; i < Size - 2; ++i) {
528 EndPoints[i] = EndPoints[i + 2];
530 EndPoints.resize(Size - 2);
534 // If in the end we have a single range, it is possible that it is now the
535 // full range. Just drop the metadata in that case.
536 if (EndPoints.size() == 2) {
537 ConstantRange Range(cast<ConstantInt>(EndPoints[0])->getValue(),
538 cast<ConstantInt>(EndPoints[1])->getValue());
539 if (Range.isFullSet())
543 return MDNode::get(A->getContext(), EndPoints);
546 //===----------------------------------------------------------------------===//
547 // NamedMDNode implementation.
550 static SmallVector<TrackingVH<MDNode>, 4> &getNMDOps(void *Operands) {
551 return *(SmallVector<TrackingVH<MDNode>, 4> *)Operands;
554 NamedMDNode::NamedMDNode(const Twine &N)
555 : Name(N.str()), Parent(nullptr),
556 Operands(new SmallVector<TrackingVH<MDNode>, 4>()) {}
558 NamedMDNode::~NamedMDNode() {
560 delete &getNMDOps(Operands);
563 unsigned NamedMDNode::getNumOperands() const {
564 return (unsigned)getNMDOps(Operands).size();
567 MDNode *NamedMDNode::getOperand(unsigned i) const {
568 assert(i < getNumOperands() && "Invalid Operand number!");
569 return &*getNMDOps(Operands)[i];
572 void NamedMDNode::addOperand(MDNode *M) {
573 assert(!M->isFunctionLocal() &&
574 "NamedMDNode operands must not be function-local!");
575 getNMDOps(Operands).push_back(TrackingVH<MDNode>(M));
578 void NamedMDNode::eraseFromParent() {
579 getParent()->eraseNamedMetadata(this);
582 void NamedMDNode::dropAllReferences() {
583 getNMDOps(Operands).clear();
586 StringRef NamedMDNode::getName() const {
587 return StringRef(Name);
590 //===----------------------------------------------------------------------===//
591 // Instruction Metadata method implementations.
594 void Instruction::setMetadata(StringRef Kind, MDNode *Node) {
595 if (!Node && !hasMetadata())
597 setMetadata(getContext().getMDKindID(Kind), Node);
600 MDNode *Instruction::getMetadataImpl(StringRef Kind) const {
601 return getMetadataImpl(getContext().getMDKindID(Kind));
604 void Instruction::dropUnknownMetadata(ArrayRef<unsigned> KnownIDs) {
605 SmallSet<unsigned, 5> KnownSet;
606 KnownSet.insert(KnownIDs.begin(), KnownIDs.end());
608 // Drop debug if needed
609 if (KnownSet.erase(LLVMContext::MD_dbg))
612 if (!hasMetadataHashEntry())
613 return; // Nothing to remove!
615 DenseMap<const Instruction *, LLVMContextImpl::MDMapTy> &MetadataStore =
616 getContext().pImpl->MetadataStore;
618 if (KnownSet.empty()) {
619 // Just drop our entry at the store.
620 MetadataStore.erase(this);
621 setHasMetadataHashEntry(false);
625 LLVMContextImpl::MDMapTy &Info = MetadataStore[this];
628 // Walk the array and drop any metadata we don't know.
629 for (I = 0, E = Info.size(); I != E;) {
630 if (KnownSet.count(Info[I].first)) {
635 Info[I] = Info.back();
639 assert(E == Info.size());
642 // Drop our entry at the store.
643 MetadataStore.erase(this);
644 setHasMetadataHashEntry(false);
648 /// setMetadata - Set the metadata of of the specified kind to the specified
649 /// node. This updates/replaces metadata if already present, or removes it if
651 void Instruction::setMetadata(unsigned KindID, MDNode *Node) {
652 if (!Node && !hasMetadata())
655 // Handle 'dbg' as a special case since it is not stored in the hash table.
656 if (KindID == LLVMContext::MD_dbg) {
657 DbgLoc = DebugLoc::getFromDILocation(Node);
661 // Handle the case when we're adding/updating metadata on an instruction.
663 LLVMContextImpl::MDMapTy &Info = getContext().pImpl->MetadataStore[this];
664 assert(!Info.empty() == hasMetadataHashEntry() &&
665 "HasMetadata bit is wonked");
667 setHasMetadataHashEntry(true);
669 // Handle replacement of an existing value.
671 if (P.first == KindID) {
677 // No replacement, just add it to the list.
678 Info.push_back(std::make_pair(KindID, Node));
682 // Otherwise, we're removing metadata from an instruction.
683 assert((hasMetadataHashEntry() ==
684 (getContext().pImpl->MetadataStore.count(this) > 0)) &&
685 "HasMetadata bit out of date!");
686 if (!hasMetadataHashEntry())
687 return; // Nothing to remove!
688 LLVMContextImpl::MDMapTy &Info = getContext().pImpl->MetadataStore[this];
690 // Common case is removing the only entry.
691 if (Info.size() == 1 && Info[0].first == KindID) {
692 getContext().pImpl->MetadataStore.erase(this);
693 setHasMetadataHashEntry(false);
697 // Handle removal of an existing value.
698 for (unsigned i = 0, e = Info.size(); i != e; ++i)
699 if (Info[i].first == KindID) {
700 Info[i] = Info.back();
702 assert(!Info.empty() && "Removing last entry should be handled above");
705 // Otherwise, removing an entry that doesn't exist on the instruction.
708 void Instruction::setAAMetadata(const AAMDNodes &N) {
709 setMetadata(LLVMContext::MD_tbaa, N.TBAA);
710 setMetadata(LLVMContext::MD_alias_scope, N.Scope);
711 setMetadata(LLVMContext::MD_noalias, N.NoAlias);
714 MDNode *Instruction::getMetadataImpl(unsigned KindID) const {
715 // Handle 'dbg' as a special case since it is not stored in the hash table.
716 if (KindID == LLVMContext::MD_dbg)
717 return DbgLoc.getAsMDNode(getContext());
719 if (!hasMetadataHashEntry()) return nullptr;
721 LLVMContextImpl::MDMapTy &Info = getContext().pImpl->MetadataStore[this];
722 assert(!Info.empty() && "bit out of sync with hash table");
724 for (const auto &I : Info)
725 if (I.first == KindID)
730 void Instruction::getAllMetadataImpl(
731 SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
734 // Handle 'dbg' as a special case since it is not stored in the hash table.
735 if (!DbgLoc.isUnknown()) {
736 Result.push_back(std::make_pair((unsigned)LLVMContext::MD_dbg,
737 DbgLoc.getAsMDNode(getContext())));
738 if (!hasMetadataHashEntry()) return;
741 assert(hasMetadataHashEntry() &&
742 getContext().pImpl->MetadataStore.count(this) &&
743 "Shouldn't have called this");
744 const LLVMContextImpl::MDMapTy &Info =
745 getContext().pImpl->MetadataStore.find(this)->second;
746 assert(!Info.empty() && "Shouldn't have called this");
748 Result.append(Info.begin(), Info.end());
750 // Sort the resulting array so it is stable.
751 if (Result.size() > 1)
752 array_pod_sort(Result.begin(), Result.end());
755 void Instruction::getAllMetadataOtherThanDebugLocImpl(
756 SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
758 assert(hasMetadataHashEntry() &&
759 getContext().pImpl->MetadataStore.count(this) &&
760 "Shouldn't have called this");
761 const LLVMContextImpl::MDMapTy &Info =
762 getContext().pImpl->MetadataStore.find(this)->second;
763 assert(!Info.empty() && "Shouldn't have called this");
764 Result.append(Info.begin(), Info.end());
766 // Sort the resulting array so it is stable.
767 if (Result.size() > 1)
768 array_pod_sort(Result.begin(), Result.end());
771 /// clearMetadataHashEntries - Clear all hashtable-based metadata from
772 /// this instruction.
773 void Instruction::clearMetadataHashEntries() {
774 assert(hasMetadataHashEntry() && "Caller should check");
775 getContext().pImpl->MetadataStore.erase(this);
776 setHasMetadataHashEntry(false);