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 //===----------------------------------------------------------------------===//
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"
28 using namespace llvm;
30 //===----------------------------------------------------------------------===//
31 // MDString implementation.
32 //
34 void MDString::anchor() { }
36 MDString::MDString(LLVMContext &C)
37 : Value(Type::getMetadataTy(C), Value::MDStringVal) {}
39 MDString *MDString::get(LLVMContext &Context, StringRef Str) {
40 auto &Store = Context.pImpl->MDStringCache;
41 auto I = Store.find(Str);
42 if (I != Store.end())
43 return &I->second;
45 auto *Entry =
46 StringMapEntry<MDString>::Create(Str, Store.getAllocator(), Context);
47 bool WasInserted = Store.insert(Entry);
48 (void)WasInserted;
49 assert(WasInserted && "Expected entry to be inserted");
50 return &Entry->second;
51 }
53 StringRef MDString::getString() const {
54 return StringMapEntry<MDString>::GetStringMapEntryFromValue(*this).first();
55 }
57 //===----------------------------------------------------------------------===//
58 // MDNodeOperand implementation.
59 //
61 // Use CallbackVH to hold MDNode operands.
62 namespace llvm {
63 class MDNodeOperand : public CallbackVH {
64 MDNode *getParent() {
65 MDNodeOperand *Cur = this;
67 while (Cur->getValPtrInt() != 1)
68 --Cur;
70 assert(Cur->getValPtrInt() == 1 &&
71 "Couldn't find the beginning of the operand list!");
72 return reinterpret_cast<MDNode*>(Cur) - 1;
73 }
75 public:
76 MDNodeOperand(Value *V) : CallbackVH(V) {}
77 virtual ~MDNodeOperand();
79 void set(Value *V) {
80 unsigned IsFirst = this->getValPtrInt();
81 this->setValPtr(V);
82 this->setAsFirstOperand(IsFirst);
83 }
85 /// \brief Accessor method to mark the operand as the first in the list.
86 void setAsFirstOperand(unsigned V) { this->setValPtrInt(V); }
88 void deleted() override;
89 void allUsesReplacedWith(Value *NV) override;
90 };
91 } // end namespace llvm.
93 // Provide out-of-line definition to prevent weak vtable.
94 MDNodeOperand::~MDNodeOperand() {}
96 void MDNodeOperand::deleted() {
97 getParent()->replaceOperand(this, nullptr);
98 }
100 void MDNodeOperand::allUsesReplacedWith(Value *NV) {
101 getParent()->replaceOperand(this, NV);
102 }
104 //===----------------------------------------------------------------------===//
105 // MDNode implementation.
106 //
108 /// \brief Get the MDNodeOperand's coallocated on the end of the MDNode.
109 static MDNodeOperand *getOperandPtr(MDNode *N, unsigned Op) {
110 // Use <= instead of < to permit a one-past-the-end address.
111 assert(Op <= N->getNumOperands() && "Invalid operand number");
112 return reinterpret_cast<MDNodeOperand*>(N + 1) + Op;
113 }
115 void MDNode::replaceOperandWith(unsigned i, Value *Val) {
116 MDNodeOperand *Op = getOperandPtr(this, i);
117 replaceOperand(Op, Val);
118 }
120 MDNode::MDNode(LLVMContext &C, ArrayRef<Value *> Vals, bool isFunctionLocal)
121 : Metadata(Type::getMetadataTy(C), Value::MDNodeVal) {
122 NumOperands = Vals.size();
124 if (isFunctionLocal)
125 setValueSubclassData(getSubclassDataFromValue() | FunctionLocalBit);
127 // Initialize the operand list, which is co-allocated on the end of the node.
128 unsigned i = 0;
129 for (MDNodeOperand *Op = getOperandPtr(this, 0), *E = Op+NumOperands;
130 Op != E; ++Op, ++i) {
131 new (Op) MDNodeOperand(Vals[i]);
133 // Mark the first MDNodeOperand as being the first in the list of operands.
134 if (i == 0)
135 Op->setAsFirstOperand(1);
136 }
137 }
139 /// ~MDNode - Destroy MDNode.
140 MDNode::~MDNode() {
141 assert((getSubclassDataFromValue() & DestroyFlag) != 0 &&
142 "Not being destroyed through destroy()?");
143 LLVMContextImpl *pImpl = getType()->getContext().pImpl;
144 if (isNotUniqued()) {
145 pImpl->NonUniquedMDNodes.erase(this);
146 } else {
147 pImpl->MDNodeSet.RemoveNode(this);
148 }
150 // Destroy the operands.
151 for (MDNodeOperand *Op = getOperandPtr(this, 0), *E = Op+NumOperands;
152 Op != E; ++Op)
153 Op->~MDNodeOperand();
154 }
156 static const Function *getFunctionForValue(Value *V) {
157 if (!V) return nullptr;
158 if (Instruction *I = dyn_cast<Instruction>(V)) {
159 BasicBlock *BB = I->getParent();
160 return BB ? BB->getParent() : nullptr;
161 }
162 if (Argument *A = dyn_cast<Argument>(V))
163 return A->getParent();
164 if (BasicBlock *BB = dyn_cast<BasicBlock>(V))
165 return BB->getParent();
166 if (MDNode *MD = dyn_cast<MDNode>(V))
167 return MD->getFunction();
168 return nullptr;
169 }
171 #ifndef NDEBUG
172 static const Function *assertLocalFunction(const MDNode *N) {
173 if (!N->isFunctionLocal()) return nullptr;
175 // FIXME: This does not handle cyclic function local metadata.
176 const Function *F = nullptr, *NewF = nullptr;
177 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
178 if (Value *V = N->getOperand(i)) {
179 if (MDNode *MD = dyn_cast<MDNode>(V))
180 NewF = assertLocalFunction(MD);
181 else
182 NewF = getFunctionForValue(V);
183 }
184 if (!F)
185 F = NewF;
186 else
187 assert((NewF == nullptr || F == NewF) &&
188 "inconsistent function-local metadata");
189 }
190 return F;
191 }
192 #endif
194 // getFunction - If this metadata is function-local and recursively has a
195 // function-local operand, return the first such operand's parent function.
196 // Otherwise, return null. getFunction() should not be used for performance-
197 // critical code because it recursively visits all the MDNode's operands.
198 const Function *MDNode::getFunction() const {
199 #ifndef NDEBUG
200 return assertLocalFunction(this);
201 #else
202 if (!isFunctionLocal()) return nullptr;
203 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
204 if (const Function *F = getFunctionForValue(getOperand(i)))
205 return F;
206 return nullptr;
207 #endif
208 }
210 // destroy - Delete this node. Only when there are no uses.
211 void MDNode::destroy() {
212 setValueSubclassData(getSubclassDataFromValue() | DestroyFlag);
213 // Placement delete, then free the memory.
214 this->~MDNode();
215 free(this);
216 }
218 /// \brief Check if the Value would require a function-local MDNode.
219 static bool isFunctionLocalValue(Value *V) {
220 return isa<Instruction>(V) || isa<Argument>(V) || isa<BasicBlock>(V) ||
221 (isa<MDNode>(V) && cast<MDNode>(V)->isFunctionLocal());
222 }
224 MDNode *MDNode::getMDNode(LLVMContext &Context, ArrayRef<Value*> Vals,
225 FunctionLocalness FL, bool Insert) {
226 LLVMContextImpl *pImpl = Context.pImpl;
228 // Add all the operand pointers. Note that we don't have to add the
229 // isFunctionLocal bit because that's implied by the operands.
230 // Note that if the operands are later nulled out, the node will be
231 // removed from the uniquing map.
232 FoldingSetNodeID ID;
233 for (Value *V : Vals)
234 ID.AddPointer(V);
236 void *InsertPoint;
237 MDNode *N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint);
239 if (N || !Insert)
240 return N;
242 bool isFunctionLocal = false;
243 switch (FL) {
244 case FL_Unknown:
245 for (Value *V : Vals) {
246 if (!V) continue;
247 if (isFunctionLocalValue(V)) {
248 isFunctionLocal = true;
249 break;
250 }
251 }
252 break;
253 case FL_No:
254 isFunctionLocal = false;
255 break;
256 case FL_Yes:
257 isFunctionLocal = true;
258 break;
259 }
261 // Coallocate space for the node and Operands together, then placement new.
262 void *Ptr = malloc(sizeof(MDNode) + Vals.size() * sizeof(MDNodeOperand));
263 N = new (Ptr) MDNode(Context, Vals, isFunctionLocal);
265 // Cache the operand hash.
266 N->Hash = ID.ComputeHash();
268 // InsertPoint will have been set by the FindNodeOrInsertPos call.
269 pImpl->MDNodeSet.InsertNode(N, InsertPoint);
271 return N;
272 }
274 MDNode *MDNode::get(LLVMContext &Context, ArrayRef<Value*> Vals) {
275 return getMDNode(Context, Vals, FL_Unknown);
276 }
278 MDNode *MDNode::getWhenValsUnresolved(LLVMContext &Context,
279 ArrayRef<Value*> Vals,
280 bool isFunctionLocal) {
281 return getMDNode(Context, Vals, isFunctionLocal ? FL_Yes : FL_No);
282 }
284 MDNode *MDNode::getIfExists(LLVMContext &Context, ArrayRef<Value*> Vals) {
285 return getMDNode(Context, Vals, FL_Unknown, false);
286 }
288 MDNode *MDNode::getTemporary(LLVMContext &Context, ArrayRef<Value*> Vals) {
289 MDNode *N =
290 (MDNode *)malloc(sizeof(MDNode) + Vals.size() * sizeof(MDNodeOperand));
291 N = new (N) MDNode(Context, Vals, FL_No);
292 N->setValueSubclassData(N->getSubclassDataFromValue() |
293 NotUniquedBit);
294 LeakDetector::addGarbageObject(N);
295 return N;
296 }
298 void MDNode::deleteTemporary(MDNode *N) {
299 assert(N->use_empty() && "Temporary MDNode has uses!");
300 assert(!N->getContext().pImpl->MDNodeSet.RemoveNode(N) &&
301 "Deleting a non-temporary uniqued node!");
302 assert(!N->getContext().pImpl->NonUniquedMDNodes.erase(N) &&
303 "Deleting a non-temporary non-uniqued node!");
304 assert((N->getSubclassDataFromValue() & NotUniquedBit) &&
305 "Temporary MDNode does not have NotUniquedBit set!");
306 assert((N->getSubclassDataFromValue() & DestroyFlag) == 0 &&
307 "Temporary MDNode has DestroyFlag set!");
308 LeakDetector::removeGarbageObject(N);
309 N->destroy();
310 }
312 /// \brief Return specified operand.
313 Value *MDNode::getOperand(unsigned i) const {
314 assert(i < getNumOperands() && "Invalid operand number");
315 return *getOperandPtr(const_cast<MDNode*>(this), i);
316 }
318 void MDNode::Profile(FoldingSetNodeID &ID) const {
319 // Add all the operand pointers. Note that we don't have to add the
320 // isFunctionLocal bit because that's implied by the operands.
321 // Note that if the operands are later nulled out, the node will be
322 // removed from the uniquing map.
323 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
324 ID.AddPointer(getOperand(i));
325 }
327 void MDNode::setIsNotUniqued() {
328 setValueSubclassData(getSubclassDataFromValue() | NotUniquedBit);
329 LLVMContextImpl *pImpl = getType()->getContext().pImpl;
330 pImpl->NonUniquedMDNodes.insert(this);
331 }
333 // Replace value from this node's operand list.
334 void MDNode::replaceOperand(MDNodeOperand *Op, Value *To) {
335 Value *From = *Op;
337 // If is possible that someone did GV->RAUW(inst), replacing a global variable
338 // with an instruction or some other function-local object. If this is a
339 // non-function-local MDNode, it can't point to a function-local object.
340 // Handle this case by implicitly dropping the MDNode reference to null.
341 // Likewise if the MDNode is function-local but for a different function.
342 if (To && isFunctionLocalValue(To)) {
343 if (!isFunctionLocal())
344 To = nullptr;
345 else {
346 const Function *F = getFunction();
347 const Function *FV = getFunctionForValue(To);
348 // Metadata can be function-local without having an associated function.
349 // So only consider functions to have changed if non-null.
350 if (F && FV && F != FV)
351 To = nullptr;
352 }
353 }
355 if (From == To)
356 return;
358 // Update the operand.
359 Op->set(To);
361 // If this node is already not being uniqued (because one of the operands
362 // already went to null), then there is nothing else to do here.
363 if (isNotUniqued()) return;
365 LLVMContextImpl *pImpl = getType()->getContext().pImpl;
367 // Remove "this" from the context map. FoldingSet doesn't have to reprofile
368 // this node to remove it, so we don't care what state the operands are in.
369 pImpl->MDNodeSet.RemoveNode(this);
371 // If we are dropping an argument to null, we choose to not unique the MDNode
372 // anymore. This commonly occurs during destruction, and uniquing these
373 // brings little reuse. Also, this means we don't need to include
374 // isFunctionLocal bits in FoldingSetNodeIDs for MDNodes.
375 if (!To) {
376 setIsNotUniqued();
377 return;
378 }
380 // Now that the node is out of the folding set, get ready to reinsert it.
381 // First, check to see if another node with the same operands already exists
382 // in the set. If so, then this node is redundant.
383 FoldingSetNodeID ID;
384 Profile(ID);
385 void *InsertPoint;
386 if (MDNode *N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint)) {
387 replaceAllUsesWith(N);
388 destroy();
389 return;
390 }
392 // Cache the operand hash.
393 Hash = ID.ComputeHash();
394 // InsertPoint will have been set by the FindNodeOrInsertPos call.
395 pImpl->MDNodeSet.InsertNode(this, InsertPoint);
397 // If this MDValue was previously function-local but no longer is, clear
398 // its function-local flag.
399 if (isFunctionLocal() && !isFunctionLocalValue(To)) {
400 bool isStillFunctionLocal = false;
401 for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
402 Value *V = getOperand(i);
403 if (!V) continue;
404 if (isFunctionLocalValue(V)) {
405 isStillFunctionLocal = true;
406 break;
407 }
408 }
409 if (!isStillFunctionLocal)
410 setValueSubclassData(getSubclassDataFromValue() & ~FunctionLocalBit);
411 }
412 }
414 MDNode *MDNode::concatenate(MDNode *A, MDNode *B) {
415 if (!A)
416 return B;
417 if (!B)
418 return A;
420 SmallVector<Value *, 4> Vals(A->getNumOperands() +
421 B->getNumOperands());
423 unsigned j = 0;
424 for (unsigned i = 0, ie = A->getNumOperands(); i != ie; ++i)
425 Vals[j++] = A->getOperand(i);
426 for (unsigned i = 0, ie = B->getNumOperands(); i != ie; ++i)
427 Vals[j++] = B->getOperand(i);
429 return MDNode::get(A->getContext(), Vals);
430 }
432 MDNode *MDNode::intersect(MDNode *A, MDNode *B) {
433 if (!A || !B)
434 return nullptr;
436 SmallVector<Value *, 4> Vals;
437 for (unsigned i = 0, ie = A->getNumOperands(); i != ie; ++i) {
438 Value *V = A->getOperand(i);
439 for (unsigned j = 0, je = B->getNumOperands(); j != je; ++j)
440 if (V == B->getOperand(j)) {
441 Vals.push_back(V);
442 break;
443 }
444 }
446 return MDNode::get(A->getContext(), Vals);
447 }
449 MDNode *MDNode::getMostGenericFPMath(MDNode *A, MDNode *B) {
450 if (!A || !B)
451 return nullptr;
453 APFloat AVal = cast<ConstantFP>(A->getOperand(0))->getValueAPF();
454 APFloat BVal = cast<ConstantFP>(B->getOperand(0))->getValueAPF();
455 if (AVal.compare(BVal) == APFloat::cmpLessThan)
456 return A;
457 return B;
458 }
460 static bool isContiguous(const ConstantRange &A, const ConstantRange &B) {
461 return A.getUpper() == B.getLower() || A.getLower() == B.getUpper();
462 }
464 static bool canBeMerged(const ConstantRange &A, const ConstantRange &B) {
465 return !A.intersectWith(B).isEmptySet() || isContiguous(A, B);
466 }
468 static bool tryMergeRange(SmallVectorImpl<Value *> &EndPoints, ConstantInt *Low,
469 ConstantInt *High) {
470 ConstantRange NewRange(Low->getValue(), High->getValue());
471 unsigned Size = EndPoints.size();
472 APInt LB = cast<ConstantInt>(EndPoints[Size - 2])->getValue();
473 APInt LE = cast<ConstantInt>(EndPoints[Size - 1])->getValue();
474 ConstantRange LastRange(LB, LE);
475 if (canBeMerged(NewRange, LastRange)) {
476 ConstantRange Union = LastRange.unionWith(NewRange);
477 Type *Ty = High->getType();
478 EndPoints[Size - 2] = ConstantInt::get(Ty, Union.getLower());
479 EndPoints[Size - 1] = ConstantInt::get(Ty, Union.getUpper());
480 return true;
481 }
482 return false;
483 }
485 static void addRange(SmallVectorImpl<Value *> &EndPoints, ConstantInt *Low,
486 ConstantInt *High) {
487 if (!EndPoints.empty())
488 if (tryMergeRange(EndPoints, Low, High))
489 return;
491 EndPoints.push_back(Low);
492 EndPoints.push_back(High);
493 }
495 MDNode *MDNode::getMostGenericRange(MDNode *A, MDNode *B) {
496 // Given two ranges, we want to compute the union of the ranges. This
497 // is slightly complitade by having to combine the intervals and merge
498 // the ones that overlap.
500 if (!A || !B)
501 return nullptr;
503 if (A == B)
504 return A;
506 // First, walk both lists in older of the lower boundary of each interval.
507 // At each step, try to merge the new interval to the last one we adedd.
508 SmallVector<Value*, 4> EndPoints;
509 int AI = 0;
510 int BI = 0;
511 int AN = A->getNumOperands() / 2;
512 int BN = B->getNumOperands() / 2;
513 while (AI < AN && BI < BN) {
514 ConstantInt *ALow = cast<ConstantInt>(A->getOperand(2 * AI));
515 ConstantInt *BLow = cast<ConstantInt>(B->getOperand(2 * BI));
517 if (ALow->getValue().slt(BLow->getValue())) {
518 addRange(EndPoints, ALow, cast<ConstantInt>(A->getOperand(2 * AI + 1)));
519 ++AI;
520 } else {
521 addRange(EndPoints, BLow, cast<ConstantInt>(B->getOperand(2 * BI + 1)));
522 ++BI;
523 }
524 }
525 while (AI < AN) {
526 addRange(EndPoints, cast<ConstantInt>(A->getOperand(2 * AI)),
527 cast<ConstantInt>(A->getOperand(2 * AI + 1)));
528 ++AI;
529 }
530 while (BI < BN) {
531 addRange(EndPoints, cast<ConstantInt>(B->getOperand(2 * BI)),
532 cast<ConstantInt>(B->getOperand(2 * BI + 1)));
533 ++BI;
534 }
536 // If we have more than 2 ranges (4 endpoints) we have to try to merge
537 // the last and first ones.
538 unsigned Size = EndPoints.size();
539 if (Size > 4) {
540 ConstantInt *FB = cast<ConstantInt>(EndPoints[0]);
541 ConstantInt *FE = cast<ConstantInt>(EndPoints[1]);
542 if (tryMergeRange(EndPoints, FB, FE)) {
543 for (unsigned i = 0; i < Size - 2; ++i) {
544 EndPoints[i] = EndPoints[i + 2];
545 }
546 EndPoints.resize(Size - 2);
547 }
548 }
550 // If in the end we have a single range, it is possible that it is now the
551 // full range. Just drop the metadata in that case.
552 if (EndPoints.size() == 2) {
553 ConstantRange Range(cast<ConstantInt>(EndPoints[0])->getValue(),
554 cast<ConstantInt>(EndPoints[1])->getValue());
555 if (Range.isFullSet())
556 return nullptr;
557 }
559 return MDNode::get(A->getContext(), EndPoints);
560 }
562 //===----------------------------------------------------------------------===//
563 // NamedMDNode implementation.
564 //
566 static SmallVector<TrackingVH<MDNode>, 4> &getNMDOps(void *Operands) {
567 return *(SmallVector<TrackingVH<MDNode>, 4> *)Operands;
568 }
570 NamedMDNode::NamedMDNode(const Twine &N)
571 : Name(N.str()), Parent(nullptr),
572 Operands(new SmallVector<TrackingVH<MDNode>, 4>()) {}
574 NamedMDNode::~NamedMDNode() {
575 dropAllReferences();
576 delete &getNMDOps(Operands);
577 }
579 unsigned NamedMDNode::getNumOperands() const {
580 return (unsigned)getNMDOps(Operands).size();
581 }
583 MDNode *NamedMDNode::getOperand(unsigned i) const {
584 assert(i < getNumOperands() && "Invalid Operand number!");
585 return &*getNMDOps(Operands)[i];
586 }
588 void NamedMDNode::addOperand(MDNode *M) {
589 assert(!M->isFunctionLocal() &&
590 "NamedMDNode operands must not be function-local!");
591 getNMDOps(Operands).push_back(TrackingVH<MDNode>(M));
592 }
594 void NamedMDNode::eraseFromParent() {
595 getParent()->eraseNamedMetadata(this);
596 }
598 void NamedMDNode::dropAllReferences() {
599 getNMDOps(Operands).clear();
600 }
602 StringRef NamedMDNode::getName() const {
603 return StringRef(Name);
604 }
606 //===----------------------------------------------------------------------===//
607 // Instruction Metadata method implementations.
608 //
610 void Instruction::setMetadata(StringRef Kind, MDNode *Node) {
611 if (!Node && !hasMetadata())
612 return;
613 setMetadata(getContext().getMDKindID(Kind), Node);
614 }
616 MDNode *Instruction::getMetadataImpl(StringRef Kind) const {
617 return getMetadataImpl(getContext().getMDKindID(Kind));
618 }
620 void Instruction::dropUnknownMetadata(ArrayRef<unsigned> KnownIDs) {
621 SmallSet<unsigned, 5> KnownSet;
622 KnownSet.insert(KnownIDs.begin(), KnownIDs.end());
624 // Drop debug if needed
625 if (KnownSet.erase(LLVMContext::MD_dbg))
626 DbgLoc = DebugLoc();
628 if (!hasMetadataHashEntry())
629 return; // Nothing to remove!
631 DenseMap<const Instruction *, LLVMContextImpl::MDMapTy> &MetadataStore =
632 getContext().pImpl->MetadataStore;
634 if (KnownSet.empty()) {
635 // Just drop our entry at the store.
636 MetadataStore.erase(this);
637 setHasMetadataHashEntry(false);
638 return;
639 }
641 LLVMContextImpl::MDMapTy &Info = MetadataStore[this];
642 unsigned I;
643 unsigned E;
644 // Walk the array and drop any metadata we don't know.
645 for (I = 0, E = Info.size(); I != E;) {
646 if (KnownSet.count(Info[I].first)) {
647 ++I;
648 continue;
649 }
651 Info[I] = Info.back();
652 Info.pop_back();
653 --E;
654 }
655 assert(E == Info.size());
657 if (E == 0) {
658 // Drop our entry at the store.
659 MetadataStore.erase(this);
660 setHasMetadataHashEntry(false);
661 }
662 }
664 /// setMetadata - Set the metadata of of the specified kind to the specified
665 /// node. This updates/replaces metadata if already present, or removes it if
666 /// Node is null.
667 void Instruction::setMetadata(unsigned KindID, MDNode *Node) {
668 if (!Node && !hasMetadata())
669 return;
671 // Handle 'dbg' as a special case since it is not stored in the hash table.
672 if (KindID == LLVMContext::MD_dbg) {
673 DbgLoc = DebugLoc::getFromDILocation(Node);
674 return;
675 }
677 // Handle the case when we're adding/updating metadata on an instruction.
678 if (Node) {
679 LLVMContextImpl::MDMapTy &Info = getContext().pImpl->MetadataStore[this];
680 assert(!Info.empty() == hasMetadataHashEntry() &&
681 "HasMetadata bit is wonked");
682 if (Info.empty()) {
683 setHasMetadataHashEntry(true);
684 } else {
685 // Handle replacement of an existing value.
686 for (auto &P : Info)
687 if (P.first == KindID) {
688 P.second = Node;
689 return;
690 }
691 }
693 // No replacement, just add it to the list.
694 Info.push_back(std::make_pair(KindID, Node));
695 return;
696 }
698 // Otherwise, we're removing metadata from an instruction.
699 assert((hasMetadataHashEntry() ==
700 (getContext().pImpl->MetadataStore.count(this) > 0)) &&
701 "HasMetadata bit out of date!");
702 if (!hasMetadataHashEntry())
703 return; // Nothing to remove!
704 LLVMContextImpl::MDMapTy &Info = getContext().pImpl->MetadataStore[this];
706 // Common case is removing the only entry.
707 if (Info.size() == 1 && Info[0].first == KindID) {
708 getContext().pImpl->MetadataStore.erase(this);
709 setHasMetadataHashEntry(false);
710 return;
711 }
713 // Handle removal of an existing value.
714 for (unsigned i = 0, e = Info.size(); i != e; ++i)
715 if (Info[i].first == KindID) {
716 Info[i] = Info.back();
717 Info.pop_back();
718 assert(!Info.empty() && "Removing last entry should be handled above");
719 return;
720 }
721 // Otherwise, removing an entry that doesn't exist on the instruction.
722 }
724 void Instruction::setAAMetadata(const AAMDNodes &N) {
725 setMetadata(LLVMContext::MD_tbaa, N.TBAA);
726 setMetadata(LLVMContext::MD_alias_scope, N.Scope);
727 setMetadata(LLVMContext::MD_noalias, N.NoAlias);
728 }
730 MDNode *Instruction::getMetadataImpl(unsigned KindID) const {
731 // Handle 'dbg' as a special case since it is not stored in the hash table.
732 if (KindID == LLVMContext::MD_dbg)
733 return DbgLoc.getAsMDNode(getContext());
735 if (!hasMetadataHashEntry()) return nullptr;
737 LLVMContextImpl::MDMapTy &Info = getContext().pImpl->MetadataStore[this];
738 assert(!Info.empty() && "bit out of sync with hash table");
740 for (const auto &I : Info)
741 if (I.first == KindID)
742 return I.second;
743 return nullptr;
744 }
746 void Instruction::getAllMetadataImpl(
747 SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
748 Result.clear();
750 // Handle 'dbg' as a special case since it is not stored in the hash table.
751 if (!DbgLoc.isUnknown()) {
752 Result.push_back(std::make_pair((unsigned)LLVMContext::MD_dbg,
753 DbgLoc.getAsMDNode(getContext())));
754 if (!hasMetadataHashEntry()) return;
755 }
757 assert(hasMetadataHashEntry() &&
758 getContext().pImpl->MetadataStore.count(this) &&
759 "Shouldn't have called this");
760 const LLVMContextImpl::MDMapTy &Info =
761 getContext().pImpl->MetadataStore.find(this)->second;
762 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());
769 }
771 void Instruction::getAllMetadataOtherThanDebugLocImpl(
772 SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
773 Result.clear();
774 assert(hasMetadataHashEntry() &&
775 getContext().pImpl->MetadataStore.count(this) &&
776 "Shouldn't have called this");
777 const LLVMContextImpl::MDMapTy &Info =
778 getContext().pImpl->MetadataStore.find(this)->second;
779 assert(!Info.empty() && "Shouldn't have called this");
780 Result.append(Info.begin(), Info.end());
782 // Sort the resulting array so it is stable.
783 if (Result.size() > 1)
784 array_pod_sort(Result.begin(), Result.end());
785 }
787 /// clearMetadataHashEntries - Clear all hashtable-based metadata from
788 /// this instruction.
789 void Instruction::clearMetadataHashEntries() {
790 assert(hasMetadataHashEntry() && "Caller should check");
791 getContext().pImpl->MetadataStore.erase(this);
792 setHasMetadataHashEntry(false);
793 }