1 //===- ValueMapper.cpp - Interface shared by lib/Transforms/Utils ---------===//
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 defines the MapValue function, which is shared by various parts of
11 // the lib/Transforms/Utils library.
13 //===----------------------------------------------------------------------===//
15 #include "llvm/Transforms/Utils/ValueMapper.h"
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/DenseSet.h"
19 #include "llvm/ADT/None.h"
20 #include "llvm/ADT/Optional.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/SmallVector.h"
23 #include "llvm/IR/Argument.h"
24 #include "llvm/IR/BasicBlock.h"
25 #include "llvm/IR/CallSite.h"
26 #include "llvm/IR/Constant.h"
27 #include "llvm/IR/Constants.h"
28 #include "llvm/IR/DerivedTypes.h"
29 #include "llvm/IR/Function.h"
30 #include "llvm/IR/GlobalAlias.h"
31 #include "llvm/IR/GlobalObject.h"
32 #include "llvm/IR/GlobalVariable.h"
33 #include "llvm/IR/InlineAsm.h"
34 #include "llvm/IR/Instruction.h"
35 #include "llvm/IR/Instructions.h"
36 #include "llvm/IR/Metadata.h"
37 #include "llvm/IR/Operator.h"
38 #include "llvm/IR/Type.h"
39 #include "llvm/IR/Value.h"
40 #include "llvm/Support/Casting.h"
48 // Out of line method to get vtable etc for class.
49 void ValueMapTypeRemapper::anchor() {}
50 void ValueMaterializer::anchor() {}
54 /// A basic block used in a BlockAddress whose function body is not yet
56 struct DelayedBasicBlock {
58 std::unique_ptr<BasicBlock> TempBB;
60 DelayedBasicBlock(const BlockAddress &Old)
61 : OldBB(Old.getBasicBlock()),
62 TempBB(BasicBlock::Create(Old.getContext())) {}
65 struct WorklistEntry {
76 struct AppendingGVTy {
80 struct GlobalAliaseeTy {
87 unsigned AppendingGVIsOldCtorDtor : 1;
88 unsigned AppendingGVNumNewMembers;
91 AppendingGVTy AppendingGV;
92 GlobalAliaseeTy GlobalAliasee;
97 struct MappingContext {
98 ValueToValueMapTy *VM;
99 ValueMaterializer *Materializer = nullptr;
101 /// Construct a MappingContext with a value map and materializer.
102 explicit MappingContext(ValueToValueMapTy &VM,
103 ValueMaterializer *Materializer = nullptr)
104 : VM(&VM), Materializer(Materializer) {}
108 friend class MDNodeMapper;
111 DenseSet<GlobalValue *> AlreadyScheduled;
115 ValueMapTypeRemapper *TypeMapper;
116 unsigned CurrentMCID = 0;
117 SmallVector<MappingContext, 2> MCs;
118 SmallVector<WorklistEntry, 4> Worklist;
119 SmallVector<DelayedBasicBlock, 1> DelayedBBs;
120 SmallVector<Constant *, 16> AppendingInits;
123 Mapper(ValueToValueMapTy &VM, RemapFlags Flags,
124 ValueMapTypeRemapper *TypeMapper, ValueMaterializer *Materializer)
125 : Flags(Flags), TypeMapper(TypeMapper),
126 MCs(1, MappingContext(VM, Materializer)) {}
128 /// ValueMapper should explicitly call \a flush() before destruction.
129 ~Mapper() { assert(!hasWorkToDo() && "Expected to be flushed"); }
131 bool hasWorkToDo() const { return !Worklist.empty(); }
134 registerAlternateMappingContext(ValueToValueMapTy &VM,
135 ValueMaterializer *Materializer = nullptr) {
136 MCs.push_back(MappingContext(VM, Materializer));
137 return MCs.size() - 1;
140 void addFlags(RemapFlags Flags);
142 void remapGlobalObjectMetadata(GlobalObject &GO);
144 Value *mapValue(const Value *V);
145 void remapInstruction(Instruction *I);
146 void remapFunction(Function &F);
148 Constant *mapConstant(const Constant *C) {
149 return cast_or_null<Constant>(mapValue(C));
154 /// Find the mapping for MD. Guarantees that the return will be resolved
155 /// (not an MDNode, or MDNode::isResolved() returns true).
156 Metadata *mapMetadata(const Metadata *MD);
158 void scheduleMapGlobalInitializer(GlobalVariable &GV, Constant &Init,
160 void scheduleMapAppendingVariable(GlobalVariable &GV, Constant *InitPrefix,
162 ArrayRef<Constant *> NewMembers,
164 void scheduleMapGlobalAliasee(GlobalAlias &GA, Constant &Aliasee,
166 void scheduleRemapFunction(Function &F, unsigned MCID);
171 void mapGlobalInitializer(GlobalVariable &GV, Constant &Init);
172 void mapAppendingVariable(GlobalVariable &GV, Constant *InitPrefix,
174 ArrayRef<Constant *> NewMembers);
175 void mapGlobalAliasee(GlobalAlias &GA, Constant &Aliasee);
176 void remapFunction(Function &F, ValueToValueMapTy &VM);
178 ValueToValueMapTy &getVM() { return *MCs[CurrentMCID].VM; }
179 ValueMaterializer *getMaterializer() { return MCs[CurrentMCID].Materializer; }
181 Value *mapBlockAddress(const BlockAddress &BA);
183 /// Map metadata that doesn't require visiting operands.
184 Optional<Metadata *> mapSimpleMetadata(const Metadata *MD);
186 Metadata *mapToMetadata(const Metadata *Key, Metadata *Val);
187 Metadata *mapToSelf(const Metadata *MD);
193 /// Data about a node in \a UniquedGraph.
195 bool HasChanged = false;
196 unsigned ID = std::numeric_limits<unsigned>::max();
197 TempMDNode Placeholder;
200 /// A graph of uniqued nodes.
201 struct UniquedGraph {
202 SmallDenseMap<const Metadata *, Data, 32> Info; // Node properties.
203 SmallVector<MDNode *, 16> POT; // Post-order traversal.
205 /// Propagate changed operands through the post-order traversal.
207 /// Iteratively update \a Data::HasChanged for each node based on \a
208 /// Data::HasChanged of its operands, until fixed point.
209 void propagateChanges();
211 /// Get a forward reference to a node to use as an operand.
212 Metadata &getFwdReference(MDNode &Op);
215 /// Worklist of distinct nodes whose operands need to be remapped.
216 SmallVector<MDNode *, 16> DistinctWorklist;
218 // Storage for a UniquedGraph.
219 SmallDenseMap<const Metadata *, Data, 32> InfoStorage;
220 SmallVector<MDNode *, 16> POTStorage;
223 MDNodeMapper(Mapper &M) : M(M) {}
225 /// Map a metadata node (and its transitive operands).
227 /// Map all the (unmapped) nodes in the subgraph under \c N. The iterative
228 /// algorithm handles distinct nodes and uniqued node subgraphs using
229 /// different strategies.
231 /// Distinct nodes are immediately mapped and added to \a DistinctWorklist
232 /// using \a mapDistinctNode(). Their mapping can always be computed
233 /// immediately without visiting operands, even if their operands change.
235 /// The mapping for uniqued nodes depends on whether their operands change.
236 /// \a mapTopLevelUniquedNode() traverses the transitive uniqued subgraph of
237 /// a node to calculate uniqued node mappings in bulk. Distinct leafs are
238 /// added to \a DistinctWorklist with \a mapDistinctNode().
240 /// After mapping \c N itself, this function remaps the operands of the
241 /// distinct nodes in \a DistinctWorklist until the entire subgraph under \c
242 /// N has been mapped.
243 Metadata *map(const MDNode &N);
246 /// Map a top-level uniqued node and the uniqued subgraph underneath it.
248 /// This builds up a post-order traversal of the (unmapped) uniqued subgraph
249 /// underneath \c FirstN and calculates the nodes' mapping. Each node uses
250 /// the identity mapping (\a Mapper::mapToSelf()) as long as all of its
251 /// operands uses the identity mapping.
253 /// The algorithm works as follows:
255 /// 1. \a createPOT(): traverse the uniqued subgraph under \c FirstN and
256 /// save the post-order traversal in the given \a UniquedGraph, tracking
257 /// nodes' operands change.
259 /// 2. \a UniquedGraph::propagateChanges(): propagate changed operands
260 /// through the \a UniquedGraph until fixed point, following the rule
261 /// that if a node changes, any node that references must also change.
263 /// 3. \a mapNodesInPOT(): map the uniqued nodes, creating new uniqued nodes
264 /// (referencing new operands) where necessary.
265 Metadata *mapTopLevelUniquedNode(const MDNode &FirstN);
267 /// Try to map the operand of an \a MDNode.
269 /// If \c Op is already mapped, return the mapping. If it's not an \a
270 /// MDNode, compute and return the mapping. If it's a distinct \a MDNode,
271 /// return the result of \a mapDistinctNode().
273 /// \return None if \c Op is an unmapped uniqued \a MDNode.
274 /// \post getMappedOp(Op) only returns None if this returns None.
275 Optional<Metadata *> tryToMapOperand(const Metadata *Op);
277 /// Map a distinct node.
279 /// Return the mapping for the distinct node \c N, saving the result in \a
280 /// DistinctWorklist for later remapping.
282 /// \pre \c N is not yet mapped.
283 /// \pre \c N.isDistinct().
284 MDNode *mapDistinctNode(const MDNode &N);
286 /// Get a previously mapped node.
287 Optional<Metadata *> getMappedOp(const Metadata *Op) const;
289 /// Create a post-order traversal of an unmapped uniqued node subgraph.
291 /// This traverses the metadata graph deeply enough to map \c FirstN. It
292 /// uses \a tryToMapOperand() (via \a Mapper::mapSimplifiedNode()), so any
293 /// metadata that has already been mapped will not be part of the POT.
295 /// Each node that has a changed operand from outside the graph (e.g., a
296 /// distinct node, an already-mapped uniqued node, or \a ConstantAsMetadata)
297 /// is marked with \a Data::HasChanged.
299 /// \return \c true if any nodes in \c G have \a Data::HasChanged.
300 /// \post \c G.POT is a post-order traversal ending with \c FirstN.
301 /// \post \a Data::hasChanged in \c G.Info indicates whether any node needs
302 /// to change because of operands outside the graph.
303 bool createPOT(UniquedGraph &G, const MDNode &FirstN);
305 /// Visit the operands of a uniqued node in the POT.
307 /// Visit the operands in the range from \c I to \c E, returning the first
308 /// uniqued node we find that isn't yet in \c G. \c I is always advanced to
309 /// where to continue the loop through the operands.
311 /// This sets \c HasChanged if any of the visited operands change.
312 MDNode *visitOperands(UniquedGraph &G, MDNode::op_iterator &I,
313 MDNode::op_iterator E, bool &HasChanged);
315 /// Map all the nodes in the given uniqued graph.
317 /// This visits all the nodes in \c G in post-order, using the identity
318 /// mapping or creating a new node depending on \a Data::HasChanged.
320 /// \pre \a getMappedOp() returns None for nodes in \c G, but not for any of
321 /// their operands outside of \c G.
322 /// \pre \a Data::HasChanged is true for a node in \c G iff any of its
323 /// operands have changed.
324 /// \post \a getMappedOp() returns the mapped node for every node in \c G.
325 void mapNodesInPOT(UniquedGraph &G);
327 /// Remap a node's operands using the given functor.
329 /// Iterate through the operands of \c N and update them in place using \c
332 /// \pre N.isDistinct() or N.isTemporary().
333 template <class OperandMapper>
334 void remapOperands(MDNode &N, OperandMapper mapOperand);
337 } // end anonymous namespace
339 Value *Mapper::mapValue(const Value *V) {
340 ValueToValueMapTy::iterator I = getVM().find(V);
342 // If the value already exists in the map, use it.
343 if (I != getVM().end()) {
344 assert(I->second && "Unexpected null mapping");
348 // If we have a materializer and it can materialize a value, use that.
349 if (auto *Materializer = getMaterializer()) {
350 if (Value *NewV = Materializer->materialize(const_cast<Value *>(V))) {
356 // Global values do not need to be seeded into the VM if they
357 // are using the identity mapping.
358 if (isa<GlobalValue>(V)) {
359 if (Flags & RF_NullMapMissingGlobalValues)
361 return getVM()[V] = const_cast<Value *>(V);
364 if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
365 // Inline asm may need *type* remapping.
366 FunctionType *NewTy = IA->getFunctionType();
368 NewTy = cast<FunctionType>(TypeMapper->remapType(NewTy));
370 if (NewTy != IA->getFunctionType())
371 V = InlineAsm::get(NewTy, IA->getAsmString(), IA->getConstraintString(),
372 IA->hasSideEffects(), IA->isAlignStack());
375 return getVM()[V] = const_cast<Value *>(V);
378 if (const auto *MDV = dyn_cast<MetadataAsValue>(V)) {
379 const Metadata *MD = MDV->getMetadata();
381 if (auto *LAM = dyn_cast<LocalAsMetadata>(MD)) {
382 // Look through to grab the local value.
383 if (Value *LV = mapValue(LAM->getValue())) {
384 if (V == LAM->getValue())
385 return const_cast<Value *>(V);
386 return MetadataAsValue::get(V->getContext(), ValueAsMetadata::get(LV));
389 // FIXME: always return nullptr once Verifier::verifyDominatesUse()
390 // ensures metadata operands only reference defined SSA values.
391 return (Flags & RF_IgnoreMissingLocals)
393 : MetadataAsValue::get(V->getContext(),
394 MDTuple::get(V->getContext(), None));
397 // If this is a module-level metadata and we know that nothing at the module
398 // level is changing, then use an identity mapping.
399 if (Flags & RF_NoModuleLevelChanges)
400 return getVM()[V] = const_cast<Value *>(V);
402 // Map the metadata and turn it into a value.
403 auto *MappedMD = mapMetadata(MD);
405 return getVM()[V] = const_cast<Value *>(V);
406 return getVM()[V] = MetadataAsValue::get(V->getContext(), MappedMD);
409 // Okay, this either must be a constant (which may or may not be mappable) or
410 // is something that is not in the mapping table.
411 Constant *C = const_cast<Constant*>(dyn_cast<Constant>(V));
415 if (BlockAddress *BA = dyn_cast<BlockAddress>(C))
416 return mapBlockAddress(*BA);
418 auto mapValueOrNull = [this](Value *V) {
419 auto Mapped = mapValue(V);
420 assert((Mapped || (Flags & RF_NullMapMissingGlobalValues)) &&
421 "Unexpected null mapping for constant operand without "
422 "NullMapMissingGlobalValues flag");
426 // Otherwise, we have some other constant to remap. Start by checking to see
427 // if all operands have an identity remapping.
428 unsigned OpNo = 0, NumOperands = C->getNumOperands();
429 Value *Mapped = nullptr;
430 for (; OpNo != NumOperands; ++OpNo) {
431 Value *Op = C->getOperand(OpNo);
432 Mapped = mapValueOrNull(Op);
439 // See if the type mapper wants to remap the type as well.
440 Type *NewTy = C->getType();
442 NewTy = TypeMapper->remapType(NewTy);
444 // If the result type and all operands match up, then just insert an identity
446 if (OpNo == NumOperands && NewTy == C->getType())
447 return getVM()[V] = C;
449 // Okay, we need to create a new constant. We've already processed some or
450 // all of the operands, set them all up now.
451 SmallVector<Constant*, 8> Ops;
452 Ops.reserve(NumOperands);
453 for (unsigned j = 0; j != OpNo; ++j)
454 Ops.push_back(cast<Constant>(C->getOperand(j)));
456 // If one of the operands mismatch, push it and the other mapped operands.
457 if (OpNo != NumOperands) {
458 Ops.push_back(cast<Constant>(Mapped));
460 // Map the rest of the operands that aren't processed yet.
461 for (++OpNo; OpNo != NumOperands; ++OpNo) {
462 Mapped = mapValueOrNull(C->getOperand(OpNo));
465 Ops.push_back(cast<Constant>(Mapped));
468 Type *NewSrcTy = nullptr;
470 if (auto *GEPO = dyn_cast<GEPOperator>(C))
471 NewSrcTy = TypeMapper->remapType(GEPO->getSourceElementType());
473 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
474 return getVM()[V] = CE->getWithOperands(Ops, NewTy, false, NewSrcTy);
475 if (isa<ConstantArray>(C))
476 return getVM()[V] = ConstantArray::get(cast<ArrayType>(NewTy), Ops);
477 if (isa<ConstantStruct>(C))
478 return getVM()[V] = ConstantStruct::get(cast<StructType>(NewTy), Ops);
479 if (isa<ConstantVector>(C))
480 return getVM()[V] = ConstantVector::get(Ops);
481 // If this is a no-operand constant, it must be because the type was remapped.
482 if (isa<UndefValue>(C))
483 return getVM()[V] = UndefValue::get(NewTy);
484 if (isa<ConstantAggregateZero>(C))
485 return getVM()[V] = ConstantAggregateZero::get(NewTy);
486 assert(isa<ConstantPointerNull>(C));
487 return getVM()[V] = ConstantPointerNull::get(cast<PointerType>(NewTy));
490 Value *Mapper::mapBlockAddress(const BlockAddress &BA) {
491 Function *F = cast<Function>(mapValue(BA.getFunction()));
493 // F may not have materialized its initializer. In that case, create a
494 // dummy basic block for now, and replace it once we've materialized all
498 DelayedBBs.push_back(DelayedBasicBlock(BA));
499 BB = DelayedBBs.back().TempBB.get();
501 BB = cast_or_null<BasicBlock>(mapValue(BA.getBasicBlock()));
504 return getVM()[&BA] = BlockAddress::get(F, BB ? BB : BA.getBasicBlock());
507 Metadata *Mapper::mapToMetadata(const Metadata *Key, Metadata *Val) {
508 getVM().MD()[Key].reset(Val);
512 Metadata *Mapper::mapToSelf(const Metadata *MD) {
513 return mapToMetadata(MD, const_cast<Metadata *>(MD));
516 Optional<Metadata *> MDNodeMapper::tryToMapOperand(const Metadata *Op) {
520 if (Optional<Metadata *> MappedOp = M.mapSimpleMetadata(Op)) {
522 if (auto *CMD = dyn_cast<ConstantAsMetadata>(Op))
523 assert((!*MappedOp || M.getVM().count(CMD->getValue()) ||
524 M.getVM().getMappedMD(Op)) &&
525 "Expected Value to be memoized");
527 assert((isa<MDString>(Op) || M.getVM().getMappedMD(Op)) &&
528 "Expected result to be memoized");
533 const MDNode &N = *cast<MDNode>(Op);
535 return mapDistinctNode(N);
539 MDNode *MDNodeMapper::mapDistinctNode(const MDNode &N) {
540 assert(N.isDistinct() && "Expected a distinct node");
541 assert(!M.getVM().getMappedMD(&N) && "Expected an unmapped node");
542 DistinctWorklist.push_back(cast<MDNode>(
543 (M.Flags & RF_MoveDistinctMDs)
545 : M.mapToMetadata(&N, MDNode::replaceWithDistinct(N.clone()))));
546 return DistinctWorklist.back();
549 static ConstantAsMetadata *wrapConstantAsMetadata(const ConstantAsMetadata &CMD,
551 if (CMD.getValue() == MappedV)
552 return const_cast<ConstantAsMetadata *>(&CMD);
553 return MappedV ? ConstantAsMetadata::getConstant(MappedV) : nullptr;
556 Optional<Metadata *> MDNodeMapper::getMappedOp(const Metadata *Op) const {
560 if (Optional<Metadata *> MappedOp = M.getVM().getMappedMD(Op))
563 if (isa<MDString>(Op))
564 return const_cast<Metadata *>(Op);
566 if (auto *CMD = dyn_cast<ConstantAsMetadata>(Op))
567 return wrapConstantAsMetadata(*CMD, M.getVM().lookup(CMD->getValue()));
572 Metadata &MDNodeMapper::UniquedGraph::getFwdReference(MDNode &Op) {
573 auto Where = Info.find(&Op);
574 assert(Where != Info.end() && "Expected a valid reference");
576 auto &OpD = Where->second;
580 // Lazily construct a temporary node.
581 if (!OpD.Placeholder)
582 OpD.Placeholder = Op.clone();
584 return *OpD.Placeholder;
587 template <class OperandMapper>
588 void MDNodeMapper::remapOperands(MDNode &N, OperandMapper mapOperand) {
589 assert(!N.isUniqued() && "Expected distinct or temporary nodes");
590 for (unsigned I = 0, E = N.getNumOperands(); I != E; ++I) {
591 Metadata *Old = N.getOperand(I);
592 Metadata *New = mapOperand(Old);
595 N.replaceOperandWith(I, New);
601 /// An entry in the worklist for the post-order traversal.
602 struct POTWorklistEntry {
603 MDNode *N; ///< Current node.
604 MDNode::op_iterator Op; ///< Current operand of \c N.
606 /// Keep a flag of whether operands have changed in the worklist to avoid
607 /// hitting the map in \a UniquedGraph.
608 bool HasChanged = false;
610 POTWorklistEntry(MDNode &N) : N(&N), Op(N.op_begin()) {}
613 } // end anonymous namespace
615 bool MDNodeMapper::createPOT(UniquedGraph &G, const MDNode &FirstN) {
616 assert(G.Info.empty() && "Expected a fresh traversal");
617 assert(FirstN.isUniqued() && "Expected uniqued node in POT");
619 // Construct a post-order traversal of the uniqued subgraph under FirstN.
620 bool AnyChanges = false;
621 SmallVector<POTWorklistEntry, 16> Worklist;
622 Worklist.push_back(POTWorklistEntry(const_cast<MDNode &>(FirstN)));
623 (void)G.Info[&FirstN];
624 while (!Worklist.empty()) {
625 // Start or continue the traversal through the this node's operands.
626 auto &WE = Worklist.back();
627 if (MDNode *N = visitOperands(G, WE.Op, WE.N->op_end(), WE.HasChanged)) {
628 // Push a new node to traverse first.
629 Worklist.push_back(POTWorklistEntry(*N));
633 // Push the node onto the POT.
634 assert(WE.N->isUniqued() && "Expected only uniqued nodes");
635 assert(WE.Op == WE.N->op_end() && "Expected to visit all operands");
636 auto &D = G.Info[WE.N];
637 AnyChanges |= D.HasChanged = WE.HasChanged;
639 G.POT.push_back(WE.N);
641 // Pop the node off the worklist.
647 MDNode *MDNodeMapper::visitOperands(UniquedGraph &G, MDNode::op_iterator &I,
648 MDNode::op_iterator E, bool &HasChanged) {
650 Metadata *Op = *I++; // Increment even on early return.
651 if (Optional<Metadata *> MappedOp = tryToMapOperand(Op)) {
652 // Check if the operand changes.
653 HasChanged |= Op != *MappedOp;
657 // A uniqued metadata node.
658 MDNode &OpN = *cast<MDNode>(Op);
659 assert(OpN.isUniqued() &&
660 "Only uniqued operands cannot be mapped immediately");
661 if (G.Info.insert(std::make_pair(&OpN, Data())).second)
662 return &OpN; // This is a new one. Return it.
667 void MDNodeMapper::UniquedGraph::propagateChanges() {
671 for (MDNode *N : POT) {
676 if (llvm::none_of(N->operands(), [&](const Metadata *Op) {
677 auto Where = Info.find(Op);
678 return Where != Info.end() && Where->second.HasChanged;
682 AnyChanges = D.HasChanged = true;
684 } while (AnyChanges);
687 void MDNodeMapper::mapNodesInPOT(UniquedGraph &G) {
688 // Construct uniqued nodes, building forward references as necessary.
689 SmallVector<MDNode *, 16> CyclicNodes;
690 for (auto *N : G.POT) {
693 // The node hasn't changed.
698 // Remember whether this node had a placeholder.
699 bool HadPlaceholder(D.Placeholder);
701 // Clone the uniqued node and remap the operands.
702 TempMDNode ClonedN = D.Placeholder ? std::move(D.Placeholder) : N->clone();
703 remapOperands(*ClonedN, [this, &D, &G](Metadata *Old) {
704 if (Optional<Metadata *> MappedOp = getMappedOp(Old))
707 assert(G.Info[Old].ID > D.ID && "Expected a forward reference");
708 return &G.getFwdReference(*cast<MDNode>(Old));
711 auto *NewN = MDNode::replaceWithUniqued(std::move(ClonedN));
712 M.mapToMetadata(N, NewN);
714 // Nodes that were referenced out of order in the POT are involved in a
717 CyclicNodes.push_back(NewN);
721 for (auto *N : CyclicNodes)
722 if (!N->isResolved())
726 Metadata *MDNodeMapper::map(const MDNode &N) {
727 assert(DistinctWorklist.empty() && "MDNodeMapper::map is not recursive");
728 assert(!(M.Flags & RF_NoModuleLevelChanges) &&
729 "MDNodeMapper::map assumes module-level changes");
731 // Require resolved nodes whenever metadata might be remapped.
732 assert(N.isResolved() && "Unexpected unresolved node");
735 N.isUniqued() ? mapTopLevelUniquedNode(N) : mapDistinctNode(N);
736 while (!DistinctWorklist.empty())
737 remapOperands(*DistinctWorklist.pop_back_val(), [this](Metadata *Old) {
738 if (Optional<Metadata *> MappedOp = tryToMapOperand(Old))
740 return mapTopLevelUniquedNode(*cast<MDNode>(Old));
745 Metadata *MDNodeMapper::mapTopLevelUniquedNode(const MDNode &FirstN) {
746 assert(FirstN.isUniqued() && "Expected uniqued node");
748 // Create a post-order traversal of uniqued nodes under FirstN.
750 if (!createPOT(G, FirstN)) {
751 // Return early if no nodes have changed.
752 for (const MDNode *N : G.POT)
754 return &const_cast<MDNode &>(FirstN);
757 // Update graph with all nodes that have changed.
758 G.propagateChanges();
760 // Map all the nodes in the graph.
763 // Return the original node, remapped.
764 return *getMappedOp(&FirstN);
769 struct MapMetadataDisabler {
770 ValueToValueMapTy &VM;
772 MapMetadataDisabler(ValueToValueMapTy &VM) : VM(VM) {
773 VM.disableMapMetadata();
776 ~MapMetadataDisabler() { VM.enableMapMetadata(); }
779 } // end anonymous namespace
781 Optional<Metadata *> Mapper::mapSimpleMetadata(const Metadata *MD) {
782 // If the value already exists in the map, use it.
783 if (Optional<Metadata *> NewMD = getVM().getMappedMD(MD))
786 if (isa<MDString>(MD))
787 return const_cast<Metadata *>(MD);
789 // This is a module-level metadata. If nothing at the module level is
790 // changing, use an identity mapping.
791 if ((Flags & RF_NoModuleLevelChanges))
792 return const_cast<Metadata *>(MD);
794 if (auto *CMD = dyn_cast<ConstantAsMetadata>(MD)) {
795 // Disallow recursion into metadata mapping through mapValue.
796 MapMetadataDisabler MMD(getVM());
798 // Don't memoize ConstantAsMetadata. Instead of lasting until the
799 // LLVMContext is destroyed, they can be deleted when the GlobalValue they
800 // reference is destructed. These aren't super common, so the extra
801 // indirection isn't that expensive.
802 return wrapConstantAsMetadata(*CMD, mapValue(CMD->getValue()));
805 assert(isa<MDNode>(MD) && "Expected a metadata node");
810 Metadata *Mapper::mapMetadata(const Metadata *MD) {
811 assert(MD && "Expected valid metadata");
812 assert(!isa<LocalAsMetadata>(MD) && "Unexpected local metadata");
814 if (Optional<Metadata *> NewMD = mapSimpleMetadata(MD))
817 return MDNodeMapper(*this).map(*cast<MDNode>(MD));
820 void Mapper::flush() {
821 // Flush out the worklist of global values.
822 while (!Worklist.empty()) {
823 WorklistEntry E = Worklist.pop_back_val();
824 CurrentMCID = E.MCID;
826 case WorklistEntry::MapGlobalInit:
827 E.Data.GVInit.GV->setInitializer(mapConstant(E.Data.GVInit.Init));
828 remapGlobalObjectMetadata(*E.Data.GVInit.GV);
830 case WorklistEntry::MapAppendingVar: {
831 unsigned PrefixSize = AppendingInits.size() - E.AppendingGVNumNewMembers;
832 mapAppendingVariable(*E.Data.AppendingGV.GV,
833 E.Data.AppendingGV.InitPrefix,
834 E.AppendingGVIsOldCtorDtor,
835 makeArrayRef(AppendingInits).slice(PrefixSize));
836 AppendingInits.resize(PrefixSize);
839 case WorklistEntry::MapGlobalAliasee:
840 E.Data.GlobalAliasee.GA->setAliasee(
841 mapConstant(E.Data.GlobalAliasee.Aliasee));
843 case WorklistEntry::RemapFunction:
844 remapFunction(*E.Data.RemapF);
850 // Finish logic for block addresses now that all global values have been
852 while (!DelayedBBs.empty()) {
853 DelayedBasicBlock DBB = DelayedBBs.pop_back_val();
854 BasicBlock *BB = cast_or_null<BasicBlock>(mapValue(DBB.OldBB));
855 DBB.TempBB->replaceAllUsesWith(BB ? BB : DBB.OldBB);
859 void Mapper::remapInstruction(Instruction *I) {
861 for (Use &Op : I->operands()) {
862 Value *V = mapValue(Op);
863 // If we aren't ignoring missing entries, assert that something happened.
867 assert((Flags & RF_IgnoreMissingLocals) &&
868 "Referenced value not in value map!");
871 // Remap phi nodes' incoming blocks.
872 if (PHINode *PN = dyn_cast<PHINode>(I)) {
873 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
874 Value *V = mapValue(PN->getIncomingBlock(i));
875 // If we aren't ignoring missing entries, assert that something happened.
877 PN->setIncomingBlock(i, cast<BasicBlock>(V));
879 assert((Flags & RF_IgnoreMissingLocals) &&
880 "Referenced block not in value map!");
884 // Remap attached metadata.
885 SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
886 I->getAllMetadata(MDs);
887 for (const auto &MI : MDs) {
888 MDNode *Old = MI.second;
889 MDNode *New = cast_or_null<MDNode>(mapMetadata(Old));
891 I->setMetadata(MI.first, New);
897 // If the instruction's type is being remapped, do so now.
898 if (auto CS = CallSite(I)) {
899 SmallVector<Type *, 3> Tys;
900 FunctionType *FTy = CS.getFunctionType();
901 Tys.reserve(FTy->getNumParams());
902 for (Type *Ty : FTy->params())
903 Tys.push_back(TypeMapper->remapType(Ty));
904 CS.mutateFunctionType(FunctionType::get(
905 TypeMapper->remapType(I->getType()), Tys, FTy->isVarArg()));
908 if (auto *AI = dyn_cast<AllocaInst>(I))
909 AI->setAllocatedType(TypeMapper->remapType(AI->getAllocatedType()));
910 if (auto *GEP = dyn_cast<GetElementPtrInst>(I)) {
911 GEP->setSourceElementType(
912 TypeMapper->remapType(GEP->getSourceElementType()));
913 GEP->setResultElementType(
914 TypeMapper->remapType(GEP->getResultElementType()));
916 I->mutateType(TypeMapper->remapType(I->getType()));
919 void Mapper::remapGlobalObjectMetadata(GlobalObject &GO) {
920 SmallVector<std::pair<unsigned, MDNode *>, 8> MDs;
921 GO.getAllMetadata(MDs);
923 for (const auto &I : MDs)
924 GO.addMetadata(I.first, *cast<MDNode>(mapMetadata(I.second)));
927 void Mapper::remapFunction(Function &F) {
928 // Remap the operands.
929 for (Use &Op : F.operands())
933 // Remap the metadata attachments.
934 remapGlobalObjectMetadata(F);
936 // Remap the argument types.
938 for (Argument &A : F.args())
939 A.mutateType(TypeMapper->remapType(A.getType()));
941 // Remap the instructions.
942 for (BasicBlock &BB : F)
943 for (Instruction &I : BB)
944 remapInstruction(&I);
947 void Mapper::mapAppendingVariable(GlobalVariable &GV, Constant *InitPrefix,
949 ArrayRef<Constant *> NewMembers) {
950 SmallVector<Constant *, 16> Elements;
952 unsigned NumElements =
953 cast<ArrayType>(InitPrefix->getType())->getNumElements();
954 for (unsigned I = 0; I != NumElements; ++I)
955 Elements.push_back(InitPrefix->getAggregateElement(I));
958 PointerType *VoidPtrTy;
961 // FIXME: This upgrade is done during linking to support the C API. See
962 // also IRLinker::linkAppendingVarProto() in IRMover.cpp.
963 VoidPtrTy = Type::getInt8Ty(GV.getContext())->getPointerTo();
964 auto &ST = *cast<StructType>(NewMembers.front()->getType());
965 Type *Tys[3] = {ST.getElementType(0), ST.getElementType(1), VoidPtrTy};
966 EltTy = StructType::get(GV.getContext(), Tys, false);
969 for (auto *V : NewMembers) {
972 auto *S = cast<ConstantStruct>(V);
973 auto *E1 = cast<Constant>(mapValue(S->getOperand(0)));
974 auto *E2 = cast<Constant>(mapValue(S->getOperand(1)));
975 Constant *Null = Constant::getNullValue(VoidPtrTy);
976 NewV = ConstantStruct::get(cast<StructType>(EltTy), E1, E2, Null);
978 NewV = cast_or_null<Constant>(mapValue(V));
980 Elements.push_back(NewV);
983 GV.setInitializer(ConstantArray::get(
984 cast<ArrayType>(GV.getType()->getElementType()), Elements));
987 void Mapper::scheduleMapGlobalInitializer(GlobalVariable &GV, Constant &Init,
989 assert(AlreadyScheduled.insert(&GV).second && "Should not reschedule");
990 assert(MCID < MCs.size() && "Invalid mapping context");
993 WE.Kind = WorklistEntry::MapGlobalInit;
995 WE.Data.GVInit.GV = &GV;
996 WE.Data.GVInit.Init = &Init;
997 Worklist.push_back(WE);
1000 void Mapper::scheduleMapAppendingVariable(GlobalVariable &GV,
1001 Constant *InitPrefix,
1003 ArrayRef<Constant *> NewMembers,
1005 assert(AlreadyScheduled.insert(&GV).second && "Should not reschedule");
1006 assert(MCID < MCs.size() && "Invalid mapping context");
1009 WE.Kind = WorklistEntry::MapAppendingVar;
1011 WE.Data.AppendingGV.GV = &GV;
1012 WE.Data.AppendingGV.InitPrefix = InitPrefix;
1013 WE.AppendingGVIsOldCtorDtor = IsOldCtorDtor;
1014 WE.AppendingGVNumNewMembers = NewMembers.size();
1015 Worklist.push_back(WE);
1016 AppendingInits.append(NewMembers.begin(), NewMembers.end());
1019 void Mapper::scheduleMapGlobalAliasee(GlobalAlias &GA, Constant &Aliasee,
1021 assert(AlreadyScheduled.insert(&GA).second && "Should not reschedule");
1022 assert(MCID < MCs.size() && "Invalid mapping context");
1025 WE.Kind = WorklistEntry::MapGlobalAliasee;
1027 WE.Data.GlobalAliasee.GA = &GA;
1028 WE.Data.GlobalAliasee.Aliasee = &Aliasee;
1029 Worklist.push_back(WE);
1032 void Mapper::scheduleRemapFunction(Function &F, unsigned MCID) {
1033 assert(AlreadyScheduled.insert(&F).second && "Should not reschedule");
1034 assert(MCID < MCs.size() && "Invalid mapping context");
1037 WE.Kind = WorklistEntry::RemapFunction;
1039 WE.Data.RemapF = &F;
1040 Worklist.push_back(WE);
1043 void Mapper::addFlags(RemapFlags Flags) {
1044 assert(!hasWorkToDo() && "Expected to have flushed the worklist");
1045 this->Flags = this->Flags | Flags;
1048 static Mapper *getAsMapper(void *pImpl) {
1049 return reinterpret_cast<Mapper *>(pImpl);
1054 class FlushingMapper {
1058 explicit FlushingMapper(void *pImpl) : M(*getAsMapper(pImpl)) {
1059 assert(!M.hasWorkToDo() && "Expected to be flushed");
1062 ~FlushingMapper() { M.flush(); }
1064 Mapper *operator->() const { return &M; }
1067 } // end anonymous namespace
1069 ValueMapper::ValueMapper(ValueToValueMapTy &VM, RemapFlags Flags,
1070 ValueMapTypeRemapper *TypeMapper,
1071 ValueMaterializer *Materializer)
1072 : pImpl(new Mapper(VM, Flags, TypeMapper, Materializer)) {}
1074 ValueMapper::~ValueMapper() { delete getAsMapper(pImpl); }
1077 ValueMapper::registerAlternateMappingContext(ValueToValueMapTy &VM,
1078 ValueMaterializer *Materializer) {
1079 return getAsMapper(pImpl)->registerAlternateMappingContext(VM, Materializer);
1082 void ValueMapper::addFlags(RemapFlags Flags) {
1083 FlushingMapper(pImpl)->addFlags(Flags);
1086 Value *ValueMapper::mapValue(const Value &V) {
1087 return FlushingMapper(pImpl)->mapValue(&V);
1090 Constant *ValueMapper::mapConstant(const Constant &C) {
1091 return cast_or_null<Constant>(mapValue(C));
1094 Metadata *ValueMapper::mapMetadata(const Metadata &MD) {
1095 return FlushingMapper(pImpl)->mapMetadata(&MD);
1098 MDNode *ValueMapper::mapMDNode(const MDNode &N) {
1099 return cast_or_null<MDNode>(mapMetadata(N));
1102 void ValueMapper::remapInstruction(Instruction &I) {
1103 FlushingMapper(pImpl)->remapInstruction(&I);
1106 void ValueMapper::remapFunction(Function &F) {
1107 FlushingMapper(pImpl)->remapFunction(F);
1110 void ValueMapper::scheduleMapGlobalInitializer(GlobalVariable &GV,
1113 getAsMapper(pImpl)->scheduleMapGlobalInitializer(GV, Init, MCID);
1116 void ValueMapper::scheduleMapAppendingVariable(GlobalVariable &GV,
1117 Constant *InitPrefix,
1119 ArrayRef<Constant *> NewMembers,
1121 getAsMapper(pImpl)->scheduleMapAppendingVariable(
1122 GV, InitPrefix, IsOldCtorDtor, NewMembers, MCID);
1125 void ValueMapper::scheduleMapGlobalAliasee(GlobalAlias &GA, Constant &Aliasee,
1127 getAsMapper(pImpl)->scheduleMapGlobalAliasee(GA, Aliasee, MCID);
1130 void ValueMapper::scheduleRemapFunction(Function &F, unsigned MCID) {
1131 getAsMapper(pImpl)->scheduleRemapFunction(F, MCID);