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/DebugInfoMetadata.h"
29 #include "llvm/IR/DerivedTypes.h"
30 #include "llvm/IR/Function.h"
31 #include "llvm/IR/GlobalAlias.h"
32 #include "llvm/IR/GlobalObject.h"
33 #include "llvm/IR/GlobalVariable.h"
34 #include "llvm/IR/InlineAsm.h"
35 #include "llvm/IR/Instruction.h"
36 #include "llvm/IR/Instructions.h"
37 #include "llvm/IR/Metadata.h"
38 #include "llvm/IR/Operator.h"
39 #include "llvm/IR/Type.h"
40 #include "llvm/IR/Value.h"
41 #include "llvm/Support/Casting.h"
49 // Out of line method to get vtable etc for class.
50 void ValueMapTypeRemapper::anchor() {}
51 void ValueMaterializer::anchor() {}
55 /// A basic block used in a BlockAddress whose function body is not yet
57 struct DelayedBasicBlock {
59 std::unique_ptr<BasicBlock> TempBB;
61 DelayedBasicBlock(const BlockAddress &Old)
62 : OldBB(Old.getBasicBlock()),
63 TempBB(BasicBlock::Create(Old.getContext())) {}
66 struct WorklistEntry {
77 struct AppendingGVTy {
81 struct GlobalAliaseeTy {
88 unsigned AppendingGVIsOldCtorDtor : 1;
89 unsigned AppendingGVNumNewMembers;
92 AppendingGVTy AppendingGV;
93 GlobalAliaseeTy GlobalAliasee;
98 struct MappingContext {
99 ValueToValueMapTy *VM;
100 ValueMaterializer *Materializer = nullptr;
102 /// Construct a MappingContext with a value map and materializer.
103 explicit MappingContext(ValueToValueMapTy &VM,
104 ValueMaterializer *Materializer = nullptr)
105 : VM(&VM), Materializer(Materializer) {}
109 friend class MDNodeMapper;
112 DenseSet<GlobalValue *> AlreadyScheduled;
116 ValueMapTypeRemapper *TypeMapper;
117 unsigned CurrentMCID = 0;
118 SmallVector<MappingContext, 2> MCs;
119 SmallVector<WorklistEntry, 4> Worklist;
120 SmallVector<DelayedBasicBlock, 1> DelayedBBs;
121 SmallVector<Constant *, 16> AppendingInits;
124 Mapper(ValueToValueMapTy &VM, RemapFlags Flags,
125 ValueMapTypeRemapper *TypeMapper, ValueMaterializer *Materializer)
126 : Flags(Flags), TypeMapper(TypeMapper),
127 MCs(1, MappingContext(VM, Materializer)) {}
129 /// ValueMapper should explicitly call \a flush() before destruction.
130 ~Mapper() { assert(!hasWorkToDo() && "Expected to be flushed"); }
132 bool hasWorkToDo() const { return !Worklist.empty(); }
135 registerAlternateMappingContext(ValueToValueMapTy &VM,
136 ValueMaterializer *Materializer = nullptr) {
137 MCs.push_back(MappingContext(VM, Materializer));
138 return MCs.size() - 1;
141 void addFlags(RemapFlags Flags);
143 void remapGlobalObjectMetadata(GlobalObject &GO);
145 Value *mapValue(const Value *V);
146 void remapInstruction(Instruction *I);
147 void remapFunction(Function &F);
149 Constant *mapConstant(const Constant *C) {
150 return cast_or_null<Constant>(mapValue(C));
155 /// Find the mapping for MD. Guarantees that the return will be resolved
156 /// (not an MDNode, or MDNode::isResolved() returns true).
157 Metadata *mapMetadata(const Metadata *MD);
159 void scheduleMapGlobalInitializer(GlobalVariable &GV, Constant &Init,
161 void scheduleMapAppendingVariable(GlobalVariable &GV, Constant *InitPrefix,
163 ArrayRef<Constant *> NewMembers,
165 void scheduleMapGlobalAliasee(GlobalAlias &GA, Constant &Aliasee,
167 void scheduleRemapFunction(Function &F, unsigned MCID);
172 void mapGlobalInitializer(GlobalVariable &GV, Constant &Init);
173 void mapAppendingVariable(GlobalVariable &GV, Constant *InitPrefix,
175 ArrayRef<Constant *> NewMembers);
176 void mapGlobalAliasee(GlobalAlias &GA, Constant &Aliasee);
177 void remapFunction(Function &F, ValueToValueMapTy &VM);
179 ValueToValueMapTy &getVM() { return *MCs[CurrentMCID].VM; }
180 ValueMaterializer *getMaterializer() { return MCs[CurrentMCID].Materializer; }
182 Value *mapBlockAddress(const BlockAddress &BA);
184 /// Map metadata that doesn't require visiting operands.
185 Optional<Metadata *> mapSimpleMetadata(const Metadata *MD);
187 Metadata *mapToMetadata(const Metadata *Key, Metadata *Val);
188 Metadata *mapToSelf(const Metadata *MD);
194 /// Data about a node in \a UniquedGraph.
196 bool HasChanged = false;
197 unsigned ID = std::numeric_limits<unsigned>::max();
198 TempMDNode Placeholder;
201 /// A graph of uniqued nodes.
202 struct UniquedGraph {
203 SmallDenseMap<const Metadata *, Data, 32> Info; // Node properties.
204 SmallVector<MDNode *, 16> POT; // Post-order traversal.
206 /// Propagate changed operands through the post-order traversal.
208 /// Iteratively update \a Data::HasChanged for each node based on \a
209 /// Data::HasChanged of its operands, until fixed point.
210 void propagateChanges();
212 /// Get a forward reference to a node to use as an operand.
213 Metadata &getFwdReference(MDNode &Op);
216 /// Worklist of distinct nodes whose operands need to be remapped.
217 SmallVector<MDNode *, 16> DistinctWorklist;
219 // Storage for a UniquedGraph.
220 SmallDenseMap<const Metadata *, Data, 32> InfoStorage;
221 SmallVector<MDNode *, 16> POTStorage;
224 MDNodeMapper(Mapper &M) : M(M) {}
226 /// Map a metadata node (and its transitive operands).
228 /// Map all the (unmapped) nodes in the subgraph under \c N. The iterative
229 /// algorithm handles distinct nodes and uniqued node subgraphs using
230 /// different strategies.
232 /// Distinct nodes are immediately mapped and added to \a DistinctWorklist
233 /// using \a mapDistinctNode(). Their mapping can always be computed
234 /// immediately without visiting operands, even if their operands change.
236 /// The mapping for uniqued nodes depends on whether their operands change.
237 /// \a mapTopLevelUniquedNode() traverses the transitive uniqued subgraph of
238 /// a node to calculate uniqued node mappings in bulk. Distinct leafs are
239 /// added to \a DistinctWorklist with \a mapDistinctNode().
241 /// After mapping \c N itself, this function remaps the operands of the
242 /// distinct nodes in \a DistinctWorklist until the entire subgraph under \c
243 /// N has been mapped.
244 Metadata *map(const MDNode &N);
247 /// Map a top-level uniqued node and the uniqued subgraph underneath it.
249 /// This builds up a post-order traversal of the (unmapped) uniqued subgraph
250 /// underneath \c FirstN and calculates the nodes' mapping. Each node uses
251 /// the identity mapping (\a Mapper::mapToSelf()) as long as all of its
252 /// operands uses the identity mapping.
254 /// The algorithm works as follows:
256 /// 1. \a createPOT(): traverse the uniqued subgraph under \c FirstN and
257 /// save the post-order traversal in the given \a UniquedGraph, tracking
258 /// nodes' operands change.
260 /// 2. \a UniquedGraph::propagateChanges(): propagate changed operands
261 /// through the \a UniquedGraph until fixed point, following the rule
262 /// that if a node changes, any node that references must also change.
264 /// 3. \a mapNodesInPOT(): map the uniqued nodes, creating new uniqued nodes
265 /// (referencing new operands) where necessary.
266 Metadata *mapTopLevelUniquedNode(const MDNode &FirstN);
268 /// Try to map the operand of an \a MDNode.
270 /// If \c Op is already mapped, return the mapping. If it's not an \a
271 /// MDNode, compute and return the mapping. If it's a distinct \a MDNode,
272 /// return the result of \a mapDistinctNode().
274 /// \return None if \c Op is an unmapped uniqued \a MDNode.
275 /// \post getMappedOp(Op) only returns None if this returns None.
276 Optional<Metadata *> tryToMapOperand(const Metadata *Op);
278 /// Map a distinct node.
280 /// Return the mapping for the distinct node \c N, saving the result in \a
281 /// DistinctWorklist for later remapping.
283 /// \pre \c N is not yet mapped.
284 /// \pre \c N.isDistinct().
285 MDNode *mapDistinctNode(const MDNode &N);
287 /// Get a previously mapped node.
288 Optional<Metadata *> getMappedOp(const Metadata *Op) const;
290 /// Create a post-order traversal of an unmapped uniqued node subgraph.
292 /// This traverses the metadata graph deeply enough to map \c FirstN. It
293 /// uses \a tryToMapOperand() (via \a Mapper::mapSimplifiedNode()), so any
294 /// metadata that has already been mapped will not be part of the POT.
296 /// Each node that has a changed operand from outside the graph (e.g., a
297 /// distinct node, an already-mapped uniqued node, or \a ConstantAsMetadata)
298 /// is marked with \a Data::HasChanged.
300 /// \return \c true if any nodes in \c G have \a Data::HasChanged.
301 /// \post \c G.POT is a post-order traversal ending with \c FirstN.
302 /// \post \a Data::hasChanged in \c G.Info indicates whether any node needs
303 /// to change because of operands outside the graph.
304 bool createPOT(UniquedGraph &G, const MDNode &FirstN);
306 /// Visit the operands of a uniqued node in the POT.
308 /// Visit the operands in the range from \c I to \c E, returning the first
309 /// uniqued node we find that isn't yet in \c G. \c I is always advanced to
310 /// where to continue the loop through the operands.
312 /// This sets \c HasChanged if any of the visited operands change.
313 MDNode *visitOperands(UniquedGraph &G, MDNode::op_iterator &I,
314 MDNode::op_iterator E, bool &HasChanged);
316 /// Map all the nodes in the given uniqued graph.
318 /// This visits all the nodes in \c G in post-order, using the identity
319 /// mapping or creating a new node depending on \a Data::HasChanged.
321 /// \pre \a getMappedOp() returns None for nodes in \c G, but not for any of
322 /// their operands outside of \c G.
323 /// \pre \a Data::HasChanged is true for a node in \c G iff any of its
324 /// operands have changed.
325 /// \post \a getMappedOp() returns the mapped node for every node in \c G.
326 void mapNodesInPOT(UniquedGraph &G);
328 /// Remap a node's operands using the given functor.
330 /// Iterate through the operands of \c N and update them in place using \c
333 /// \pre N.isDistinct() or N.isTemporary().
334 template <class OperandMapper>
335 void remapOperands(MDNode &N, OperandMapper mapOperand);
338 } // end anonymous namespace
340 Value *Mapper::mapValue(const Value *V) {
341 ValueToValueMapTy::iterator I = getVM().find(V);
343 // If the value already exists in the map, use it.
344 if (I != getVM().end()) {
345 assert(I->second && "Unexpected null mapping");
349 // If we have a materializer and it can materialize a value, use that.
350 if (auto *Materializer = getMaterializer()) {
351 if (Value *NewV = Materializer->materialize(const_cast<Value *>(V))) {
357 // Global values do not need to be seeded into the VM if they
358 // are using the identity mapping.
359 if (isa<GlobalValue>(V)) {
360 if (Flags & RF_NullMapMissingGlobalValues)
362 return getVM()[V] = const_cast<Value *>(V);
365 if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
366 // Inline asm may need *type* remapping.
367 FunctionType *NewTy = IA->getFunctionType();
369 NewTy = cast<FunctionType>(TypeMapper->remapType(NewTy));
371 if (NewTy != IA->getFunctionType())
372 V = InlineAsm::get(NewTy, IA->getAsmString(), IA->getConstraintString(),
373 IA->hasSideEffects(), IA->isAlignStack());
376 return getVM()[V] = const_cast<Value *>(V);
379 if (const auto *MDV = dyn_cast<MetadataAsValue>(V)) {
380 const Metadata *MD = MDV->getMetadata();
382 if (auto *LAM = dyn_cast<LocalAsMetadata>(MD)) {
383 // Look through to grab the local value.
384 if (Value *LV = mapValue(LAM->getValue())) {
385 if (V == LAM->getValue())
386 return const_cast<Value *>(V);
387 return MetadataAsValue::get(V->getContext(), ValueAsMetadata::get(LV));
390 // FIXME: always return nullptr once Verifier::verifyDominatesUse()
391 // ensures metadata operands only reference defined SSA values.
392 return (Flags & RF_IgnoreMissingLocals)
394 : MetadataAsValue::get(V->getContext(),
395 MDTuple::get(V->getContext(), None));
398 // If this is a module-level metadata and we know that nothing at the module
399 // level is changing, then use an identity mapping.
400 if (Flags & RF_NoModuleLevelChanges)
401 return getVM()[V] = const_cast<Value *>(V);
403 // Map the metadata and turn it into a value.
404 auto *MappedMD = mapMetadata(MD);
406 return getVM()[V] = const_cast<Value *>(V);
407 return getVM()[V] = MetadataAsValue::get(V->getContext(), MappedMD);
410 // Okay, this either must be a constant (which may or may not be mappable) or
411 // is something that is not in the mapping table.
412 Constant *C = const_cast<Constant*>(dyn_cast<Constant>(V));
416 if (BlockAddress *BA = dyn_cast<BlockAddress>(C))
417 return mapBlockAddress(*BA);
419 auto mapValueOrNull = [this](Value *V) {
420 auto Mapped = mapValue(V);
421 assert((Mapped || (Flags & RF_NullMapMissingGlobalValues)) &&
422 "Unexpected null mapping for constant operand without "
423 "NullMapMissingGlobalValues flag");
427 // Otherwise, we have some other constant to remap. Start by checking to see
428 // if all operands have an identity remapping.
429 unsigned OpNo = 0, NumOperands = C->getNumOperands();
430 Value *Mapped = nullptr;
431 for (; OpNo != NumOperands; ++OpNo) {
432 Value *Op = C->getOperand(OpNo);
433 Mapped = mapValueOrNull(Op);
440 // See if the type mapper wants to remap the type as well.
441 Type *NewTy = C->getType();
443 NewTy = TypeMapper->remapType(NewTy);
445 // If the result type and all operands match up, then just insert an identity
447 if (OpNo == NumOperands && NewTy == C->getType())
448 return getVM()[V] = C;
450 // Okay, we need to create a new constant. We've already processed some or
451 // all of the operands, set them all up now.
452 SmallVector<Constant*, 8> Ops;
453 Ops.reserve(NumOperands);
454 for (unsigned j = 0; j != OpNo; ++j)
455 Ops.push_back(cast<Constant>(C->getOperand(j)));
457 // If one of the operands mismatch, push it and the other mapped operands.
458 if (OpNo != NumOperands) {
459 Ops.push_back(cast<Constant>(Mapped));
461 // Map the rest of the operands that aren't processed yet.
462 for (++OpNo; OpNo != NumOperands; ++OpNo) {
463 Mapped = mapValueOrNull(C->getOperand(OpNo));
466 Ops.push_back(cast<Constant>(Mapped));
469 Type *NewSrcTy = nullptr;
471 if (auto *GEPO = dyn_cast<GEPOperator>(C))
472 NewSrcTy = TypeMapper->remapType(GEPO->getSourceElementType());
474 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
475 return getVM()[V] = CE->getWithOperands(Ops, NewTy, false, NewSrcTy);
476 if (isa<ConstantArray>(C))
477 return getVM()[V] = ConstantArray::get(cast<ArrayType>(NewTy), Ops);
478 if (isa<ConstantStruct>(C))
479 return getVM()[V] = ConstantStruct::get(cast<StructType>(NewTy), Ops);
480 if (isa<ConstantVector>(C))
481 return getVM()[V] = ConstantVector::get(Ops);
482 // If this is a no-operand constant, it must be because the type was remapped.
483 if (isa<UndefValue>(C))
484 return getVM()[V] = UndefValue::get(NewTy);
485 if (isa<ConstantAggregateZero>(C))
486 return getVM()[V] = ConstantAggregateZero::get(NewTy);
487 assert(isa<ConstantPointerNull>(C));
488 return getVM()[V] = ConstantPointerNull::get(cast<PointerType>(NewTy));
491 Value *Mapper::mapBlockAddress(const BlockAddress &BA) {
492 Function *F = cast<Function>(mapValue(BA.getFunction()));
494 // F may not have materialized its initializer. In that case, create a
495 // dummy basic block for now, and replace it once we've materialized all
499 DelayedBBs.push_back(DelayedBasicBlock(BA));
500 BB = DelayedBBs.back().TempBB.get();
502 BB = cast_or_null<BasicBlock>(mapValue(BA.getBasicBlock()));
505 return getVM()[&BA] = BlockAddress::get(F, BB ? BB : BA.getBasicBlock());
508 Metadata *Mapper::mapToMetadata(const Metadata *Key, Metadata *Val) {
509 getVM().MD()[Key].reset(Val);
513 Metadata *Mapper::mapToSelf(const Metadata *MD) {
514 return mapToMetadata(MD, const_cast<Metadata *>(MD));
517 Optional<Metadata *> MDNodeMapper::tryToMapOperand(const Metadata *Op) {
521 if (Optional<Metadata *> MappedOp = M.mapSimpleMetadata(Op)) {
523 if (auto *CMD = dyn_cast<ConstantAsMetadata>(Op))
524 assert((!*MappedOp || M.getVM().count(CMD->getValue()) ||
525 M.getVM().getMappedMD(Op)) &&
526 "Expected Value to be memoized");
528 assert((isa<MDString>(Op) || M.getVM().getMappedMD(Op)) &&
529 "Expected result to be memoized");
534 const MDNode &N = *cast<MDNode>(Op);
536 return mapDistinctNode(N);
540 static Metadata *cloneOrBuildODR(const MDNode &N) {
541 auto *CT = dyn_cast<DICompositeType>(&N);
542 // If ODR type uniquing is enabled, we would have uniqued composite types
543 // with identifiers during bitcode reading, so we can just use CT.
544 if (CT && CT->getContext().isODRUniquingDebugTypes() &&
545 CT->getIdentifier() != "")
546 return const_cast<DICompositeType *>(CT);
547 return MDNode::replaceWithDistinct(N.clone());
550 MDNode *MDNodeMapper::mapDistinctNode(const MDNode &N) {
551 assert(N.isDistinct() && "Expected a distinct node");
552 assert(!M.getVM().getMappedMD(&N) && "Expected an unmapped node");
553 DistinctWorklist.push_back(
554 cast<MDNode>((M.Flags & RF_MoveDistinctMDs)
556 : M.mapToMetadata(&N, cloneOrBuildODR(N))));
557 return DistinctWorklist.back();
560 static ConstantAsMetadata *wrapConstantAsMetadata(const ConstantAsMetadata &CMD,
562 if (CMD.getValue() == MappedV)
563 return const_cast<ConstantAsMetadata *>(&CMD);
564 return MappedV ? ConstantAsMetadata::getConstant(MappedV) : nullptr;
567 Optional<Metadata *> MDNodeMapper::getMappedOp(const Metadata *Op) const {
571 if (Optional<Metadata *> MappedOp = M.getVM().getMappedMD(Op))
574 if (isa<MDString>(Op))
575 return const_cast<Metadata *>(Op);
577 if (auto *CMD = dyn_cast<ConstantAsMetadata>(Op))
578 return wrapConstantAsMetadata(*CMD, M.getVM().lookup(CMD->getValue()));
583 Metadata &MDNodeMapper::UniquedGraph::getFwdReference(MDNode &Op) {
584 auto Where = Info.find(&Op);
585 assert(Where != Info.end() && "Expected a valid reference");
587 auto &OpD = Where->second;
591 // Lazily construct a temporary node.
592 if (!OpD.Placeholder)
593 OpD.Placeholder = Op.clone();
595 return *OpD.Placeholder;
598 template <class OperandMapper>
599 void MDNodeMapper::remapOperands(MDNode &N, OperandMapper mapOperand) {
600 assert(!N.isUniqued() && "Expected distinct or temporary nodes");
601 for (unsigned I = 0, E = N.getNumOperands(); I != E; ++I) {
602 Metadata *Old = N.getOperand(I);
603 Metadata *New = mapOperand(Old);
606 N.replaceOperandWith(I, New);
612 /// An entry in the worklist for the post-order traversal.
613 struct POTWorklistEntry {
614 MDNode *N; ///< Current node.
615 MDNode::op_iterator Op; ///< Current operand of \c N.
617 /// Keep a flag of whether operands have changed in the worklist to avoid
618 /// hitting the map in \a UniquedGraph.
619 bool HasChanged = false;
621 POTWorklistEntry(MDNode &N) : N(&N), Op(N.op_begin()) {}
624 } // end anonymous namespace
626 bool MDNodeMapper::createPOT(UniquedGraph &G, const MDNode &FirstN) {
627 assert(G.Info.empty() && "Expected a fresh traversal");
628 assert(FirstN.isUniqued() && "Expected uniqued node in POT");
630 // Construct a post-order traversal of the uniqued subgraph under FirstN.
631 bool AnyChanges = false;
632 SmallVector<POTWorklistEntry, 16> Worklist;
633 Worklist.push_back(POTWorklistEntry(const_cast<MDNode &>(FirstN)));
634 (void)G.Info[&FirstN];
635 while (!Worklist.empty()) {
636 // Start or continue the traversal through the this node's operands.
637 auto &WE = Worklist.back();
638 if (MDNode *N = visitOperands(G, WE.Op, WE.N->op_end(), WE.HasChanged)) {
639 // Push a new node to traverse first.
640 Worklist.push_back(POTWorklistEntry(*N));
644 // Push the node onto the POT.
645 assert(WE.N->isUniqued() && "Expected only uniqued nodes");
646 assert(WE.Op == WE.N->op_end() && "Expected to visit all operands");
647 auto &D = G.Info[WE.N];
648 AnyChanges |= D.HasChanged = WE.HasChanged;
650 G.POT.push_back(WE.N);
652 // Pop the node off the worklist.
658 MDNode *MDNodeMapper::visitOperands(UniquedGraph &G, MDNode::op_iterator &I,
659 MDNode::op_iterator E, bool &HasChanged) {
661 Metadata *Op = *I++; // Increment even on early return.
662 if (Optional<Metadata *> MappedOp = tryToMapOperand(Op)) {
663 // Check if the operand changes.
664 HasChanged |= Op != *MappedOp;
668 // A uniqued metadata node.
669 MDNode &OpN = *cast<MDNode>(Op);
670 assert(OpN.isUniqued() &&
671 "Only uniqued operands cannot be mapped immediately");
672 if (G.Info.insert(std::make_pair(&OpN, Data())).second)
673 return &OpN; // This is a new one. Return it.
678 void MDNodeMapper::UniquedGraph::propagateChanges() {
682 for (MDNode *N : POT) {
687 if (llvm::none_of(N->operands(), [&](const Metadata *Op) {
688 auto Where = Info.find(Op);
689 return Where != Info.end() && Where->second.HasChanged;
693 AnyChanges = D.HasChanged = true;
695 } while (AnyChanges);
698 void MDNodeMapper::mapNodesInPOT(UniquedGraph &G) {
699 // Construct uniqued nodes, building forward references as necessary.
700 SmallVector<MDNode *, 16> CyclicNodes;
701 for (auto *N : G.POT) {
704 // The node hasn't changed.
709 // Remember whether this node had a placeholder.
710 bool HadPlaceholder(D.Placeholder);
712 // Clone the uniqued node and remap the operands.
713 TempMDNode ClonedN = D.Placeholder ? std::move(D.Placeholder) : N->clone();
714 remapOperands(*ClonedN, [this, &D, &G](Metadata *Old) {
715 if (Optional<Metadata *> MappedOp = getMappedOp(Old))
718 assert(G.Info[Old].ID > D.ID && "Expected a forward reference");
719 return &G.getFwdReference(*cast<MDNode>(Old));
722 auto *NewN = MDNode::replaceWithUniqued(std::move(ClonedN));
723 M.mapToMetadata(N, NewN);
725 // Nodes that were referenced out of order in the POT are involved in a
728 CyclicNodes.push_back(NewN);
732 for (auto *N : CyclicNodes)
733 if (!N->isResolved())
737 Metadata *MDNodeMapper::map(const MDNode &N) {
738 assert(DistinctWorklist.empty() && "MDNodeMapper::map is not recursive");
739 assert(!(M.Flags & RF_NoModuleLevelChanges) &&
740 "MDNodeMapper::map assumes module-level changes");
742 // Require resolved nodes whenever metadata might be remapped.
743 assert(N.isResolved() && "Unexpected unresolved node");
746 N.isUniqued() ? mapTopLevelUniquedNode(N) : mapDistinctNode(N);
747 while (!DistinctWorklist.empty())
748 remapOperands(*DistinctWorklist.pop_back_val(), [this](Metadata *Old) {
749 if (Optional<Metadata *> MappedOp = tryToMapOperand(Old))
751 return mapTopLevelUniquedNode(*cast<MDNode>(Old));
756 Metadata *MDNodeMapper::mapTopLevelUniquedNode(const MDNode &FirstN) {
757 assert(FirstN.isUniqued() && "Expected uniqued node");
759 // Create a post-order traversal of uniqued nodes under FirstN.
761 if (!createPOT(G, FirstN)) {
762 // Return early if no nodes have changed.
763 for (const MDNode *N : G.POT)
765 return &const_cast<MDNode &>(FirstN);
768 // Update graph with all nodes that have changed.
769 G.propagateChanges();
771 // Map all the nodes in the graph.
774 // Return the original node, remapped.
775 return *getMappedOp(&FirstN);
780 struct MapMetadataDisabler {
781 ValueToValueMapTy &VM;
783 MapMetadataDisabler(ValueToValueMapTy &VM) : VM(VM) {
784 VM.disableMapMetadata();
787 ~MapMetadataDisabler() { VM.enableMapMetadata(); }
790 } // end anonymous namespace
792 Optional<Metadata *> Mapper::mapSimpleMetadata(const Metadata *MD) {
793 // If the value already exists in the map, use it.
794 if (Optional<Metadata *> NewMD = getVM().getMappedMD(MD))
797 if (isa<MDString>(MD))
798 return const_cast<Metadata *>(MD);
800 // This is a module-level metadata. If nothing at the module level is
801 // changing, use an identity mapping.
802 if ((Flags & RF_NoModuleLevelChanges))
803 return const_cast<Metadata *>(MD);
805 if (auto *CMD = dyn_cast<ConstantAsMetadata>(MD)) {
806 // Disallow recursion into metadata mapping through mapValue.
807 MapMetadataDisabler MMD(getVM());
809 // Don't memoize ConstantAsMetadata. Instead of lasting until the
810 // LLVMContext is destroyed, they can be deleted when the GlobalValue they
811 // reference is destructed. These aren't super common, so the extra
812 // indirection isn't that expensive.
813 return wrapConstantAsMetadata(*CMD, mapValue(CMD->getValue()));
816 assert(isa<MDNode>(MD) && "Expected a metadata node");
821 Metadata *Mapper::mapMetadata(const Metadata *MD) {
822 assert(MD && "Expected valid metadata");
823 assert(!isa<LocalAsMetadata>(MD) && "Unexpected local metadata");
825 if (Optional<Metadata *> NewMD = mapSimpleMetadata(MD))
828 return MDNodeMapper(*this).map(*cast<MDNode>(MD));
831 void Mapper::flush() {
832 // Flush out the worklist of global values.
833 while (!Worklist.empty()) {
834 WorklistEntry E = Worklist.pop_back_val();
835 CurrentMCID = E.MCID;
837 case WorklistEntry::MapGlobalInit:
838 E.Data.GVInit.GV->setInitializer(mapConstant(E.Data.GVInit.Init));
839 remapGlobalObjectMetadata(*E.Data.GVInit.GV);
841 case WorklistEntry::MapAppendingVar: {
842 unsigned PrefixSize = AppendingInits.size() - E.AppendingGVNumNewMembers;
843 mapAppendingVariable(*E.Data.AppendingGV.GV,
844 E.Data.AppendingGV.InitPrefix,
845 E.AppendingGVIsOldCtorDtor,
846 makeArrayRef(AppendingInits).slice(PrefixSize));
847 AppendingInits.resize(PrefixSize);
850 case WorklistEntry::MapGlobalAliasee:
851 E.Data.GlobalAliasee.GA->setAliasee(
852 mapConstant(E.Data.GlobalAliasee.Aliasee));
854 case WorklistEntry::RemapFunction:
855 remapFunction(*E.Data.RemapF);
861 // Finish logic for block addresses now that all global values have been
863 while (!DelayedBBs.empty()) {
864 DelayedBasicBlock DBB = DelayedBBs.pop_back_val();
865 BasicBlock *BB = cast_or_null<BasicBlock>(mapValue(DBB.OldBB));
866 DBB.TempBB->replaceAllUsesWith(BB ? BB : DBB.OldBB);
870 void Mapper::remapInstruction(Instruction *I) {
872 for (Use &Op : I->operands()) {
873 Value *V = mapValue(Op);
874 // If we aren't ignoring missing entries, assert that something happened.
878 assert((Flags & RF_IgnoreMissingLocals) &&
879 "Referenced value not in value map!");
882 // Remap phi nodes' incoming blocks.
883 if (PHINode *PN = dyn_cast<PHINode>(I)) {
884 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
885 Value *V = mapValue(PN->getIncomingBlock(i));
886 // If we aren't ignoring missing entries, assert that something happened.
888 PN->setIncomingBlock(i, cast<BasicBlock>(V));
890 assert((Flags & RF_IgnoreMissingLocals) &&
891 "Referenced block not in value map!");
895 // Remap attached metadata.
896 SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
897 I->getAllMetadata(MDs);
898 for (const auto &MI : MDs) {
899 MDNode *Old = MI.second;
900 MDNode *New = cast_or_null<MDNode>(mapMetadata(Old));
902 I->setMetadata(MI.first, New);
908 // If the instruction's type is being remapped, do so now.
909 if (auto CS = CallSite(I)) {
910 SmallVector<Type *, 3> Tys;
911 FunctionType *FTy = CS.getFunctionType();
912 Tys.reserve(FTy->getNumParams());
913 for (Type *Ty : FTy->params())
914 Tys.push_back(TypeMapper->remapType(Ty));
915 CS.mutateFunctionType(FunctionType::get(
916 TypeMapper->remapType(I->getType()), Tys, FTy->isVarArg()));
919 if (auto *AI = dyn_cast<AllocaInst>(I))
920 AI->setAllocatedType(TypeMapper->remapType(AI->getAllocatedType()));
921 if (auto *GEP = dyn_cast<GetElementPtrInst>(I)) {
922 GEP->setSourceElementType(
923 TypeMapper->remapType(GEP->getSourceElementType()));
924 GEP->setResultElementType(
925 TypeMapper->remapType(GEP->getResultElementType()));
927 I->mutateType(TypeMapper->remapType(I->getType()));
930 void Mapper::remapGlobalObjectMetadata(GlobalObject &GO) {
931 SmallVector<std::pair<unsigned, MDNode *>, 8> MDs;
932 GO.getAllMetadata(MDs);
934 for (const auto &I : MDs)
935 GO.addMetadata(I.first, *cast<MDNode>(mapMetadata(I.second)));
938 void Mapper::remapFunction(Function &F) {
939 // Remap the operands.
940 for (Use &Op : F.operands())
944 // Remap the metadata attachments.
945 remapGlobalObjectMetadata(F);
947 // Remap the argument types.
949 for (Argument &A : F.args())
950 A.mutateType(TypeMapper->remapType(A.getType()));
952 // Remap the instructions.
953 for (BasicBlock &BB : F)
954 for (Instruction &I : BB)
955 remapInstruction(&I);
958 void Mapper::mapAppendingVariable(GlobalVariable &GV, Constant *InitPrefix,
960 ArrayRef<Constant *> NewMembers) {
961 SmallVector<Constant *, 16> Elements;
963 unsigned NumElements =
964 cast<ArrayType>(InitPrefix->getType())->getNumElements();
965 for (unsigned I = 0; I != NumElements; ++I)
966 Elements.push_back(InitPrefix->getAggregateElement(I));
969 PointerType *VoidPtrTy;
972 // FIXME: This upgrade is done during linking to support the C API. See
973 // also IRLinker::linkAppendingVarProto() in IRMover.cpp.
974 VoidPtrTy = Type::getInt8Ty(GV.getContext())->getPointerTo();
975 auto &ST = *cast<StructType>(NewMembers.front()->getType());
976 Type *Tys[3] = {ST.getElementType(0), ST.getElementType(1), VoidPtrTy};
977 EltTy = StructType::get(GV.getContext(), Tys, false);
980 for (auto *V : NewMembers) {
983 auto *S = cast<ConstantStruct>(V);
984 auto *E1 = cast<Constant>(mapValue(S->getOperand(0)));
985 auto *E2 = cast<Constant>(mapValue(S->getOperand(1)));
986 Constant *Null = Constant::getNullValue(VoidPtrTy);
987 NewV = ConstantStruct::get(cast<StructType>(EltTy), E1, E2, Null);
989 NewV = cast_or_null<Constant>(mapValue(V));
991 Elements.push_back(NewV);
994 GV.setInitializer(ConstantArray::get(
995 cast<ArrayType>(GV.getType()->getElementType()), Elements));
998 void Mapper::scheduleMapGlobalInitializer(GlobalVariable &GV, Constant &Init,
1000 assert(AlreadyScheduled.insert(&GV).second && "Should not reschedule");
1001 assert(MCID < MCs.size() && "Invalid mapping context");
1004 WE.Kind = WorklistEntry::MapGlobalInit;
1006 WE.Data.GVInit.GV = &GV;
1007 WE.Data.GVInit.Init = &Init;
1008 Worklist.push_back(WE);
1011 void Mapper::scheduleMapAppendingVariable(GlobalVariable &GV,
1012 Constant *InitPrefix,
1014 ArrayRef<Constant *> NewMembers,
1016 assert(AlreadyScheduled.insert(&GV).second && "Should not reschedule");
1017 assert(MCID < MCs.size() && "Invalid mapping context");
1020 WE.Kind = WorklistEntry::MapAppendingVar;
1022 WE.Data.AppendingGV.GV = &GV;
1023 WE.Data.AppendingGV.InitPrefix = InitPrefix;
1024 WE.AppendingGVIsOldCtorDtor = IsOldCtorDtor;
1025 WE.AppendingGVNumNewMembers = NewMembers.size();
1026 Worklist.push_back(WE);
1027 AppendingInits.append(NewMembers.begin(), NewMembers.end());
1030 void Mapper::scheduleMapGlobalAliasee(GlobalAlias &GA, Constant &Aliasee,
1032 assert(AlreadyScheduled.insert(&GA).second && "Should not reschedule");
1033 assert(MCID < MCs.size() && "Invalid mapping context");
1036 WE.Kind = WorklistEntry::MapGlobalAliasee;
1038 WE.Data.GlobalAliasee.GA = &GA;
1039 WE.Data.GlobalAliasee.Aliasee = &Aliasee;
1040 Worklist.push_back(WE);
1043 void Mapper::scheduleRemapFunction(Function &F, unsigned MCID) {
1044 assert(AlreadyScheduled.insert(&F).second && "Should not reschedule");
1045 assert(MCID < MCs.size() && "Invalid mapping context");
1048 WE.Kind = WorklistEntry::RemapFunction;
1050 WE.Data.RemapF = &F;
1051 Worklist.push_back(WE);
1054 void Mapper::addFlags(RemapFlags Flags) {
1055 assert(!hasWorkToDo() && "Expected to have flushed the worklist");
1056 this->Flags = this->Flags | Flags;
1059 static Mapper *getAsMapper(void *pImpl) {
1060 return reinterpret_cast<Mapper *>(pImpl);
1065 class FlushingMapper {
1069 explicit FlushingMapper(void *pImpl) : M(*getAsMapper(pImpl)) {
1070 assert(!M.hasWorkToDo() && "Expected to be flushed");
1073 ~FlushingMapper() { M.flush(); }
1075 Mapper *operator->() const { return &M; }
1078 } // end anonymous namespace
1080 ValueMapper::ValueMapper(ValueToValueMapTy &VM, RemapFlags Flags,
1081 ValueMapTypeRemapper *TypeMapper,
1082 ValueMaterializer *Materializer)
1083 : pImpl(new Mapper(VM, Flags, TypeMapper, Materializer)) {}
1085 ValueMapper::~ValueMapper() { delete getAsMapper(pImpl); }
1088 ValueMapper::registerAlternateMappingContext(ValueToValueMapTy &VM,
1089 ValueMaterializer *Materializer) {
1090 return getAsMapper(pImpl)->registerAlternateMappingContext(VM, Materializer);
1093 void ValueMapper::addFlags(RemapFlags Flags) {
1094 FlushingMapper(pImpl)->addFlags(Flags);
1097 Value *ValueMapper::mapValue(const Value &V) {
1098 return FlushingMapper(pImpl)->mapValue(&V);
1101 Constant *ValueMapper::mapConstant(const Constant &C) {
1102 return cast_or_null<Constant>(mapValue(C));
1105 Metadata *ValueMapper::mapMetadata(const Metadata &MD) {
1106 return FlushingMapper(pImpl)->mapMetadata(&MD);
1109 MDNode *ValueMapper::mapMDNode(const MDNode &N) {
1110 return cast_or_null<MDNode>(mapMetadata(N));
1113 void ValueMapper::remapInstruction(Instruction &I) {
1114 FlushingMapper(pImpl)->remapInstruction(&I);
1117 void ValueMapper::remapFunction(Function &F) {
1118 FlushingMapper(pImpl)->remapFunction(F);
1121 void ValueMapper::scheduleMapGlobalInitializer(GlobalVariable &GV,
1124 getAsMapper(pImpl)->scheduleMapGlobalInitializer(GV, Init, MCID);
1127 void ValueMapper::scheduleMapAppendingVariable(GlobalVariable &GV,
1128 Constant *InitPrefix,
1130 ArrayRef<Constant *> NewMembers,
1132 getAsMapper(pImpl)->scheduleMapAppendingVariable(
1133 GV, InitPrefix, IsOldCtorDtor, NewMembers, MCID);
1136 void ValueMapper::scheduleMapGlobalAliasee(GlobalAlias &GA, Constant &Aliasee,
1138 getAsMapper(pImpl)->scheduleMapGlobalAliasee(GA, Aliasee, MCID);
1141 void ValueMapper::scheduleRemapFunction(Function &F, unsigned MCID) {
1142 getAsMapper(pImpl)->scheduleRemapFunction(F, MCID);