LLVM  7.0.0svn
ValueEnumerator.cpp
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1 //===- ValueEnumerator.cpp - Number values and types for bitcode writer ---===//
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 ValueEnumerator class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "ValueEnumerator.h"
15 #include "llvm/ADT/DenseMap.h"
16 #include "llvm/ADT/SmallVector.h"
17 #include "llvm/Config/llvm-config.h"
18 #include "llvm/IR/Argument.h"
19 #include "llvm/IR/Attributes.h"
20 #include "llvm/IR/BasicBlock.h"
21 #include "llvm/IR/Constant.h"
23 #include "llvm/IR/DerivedTypes.h"
24 #include "llvm/IR/Function.h"
25 #include "llvm/IR/GlobalAlias.h"
26 #include "llvm/IR/GlobalIFunc.h"
27 #include "llvm/IR/GlobalObject.h"
28 #include "llvm/IR/GlobalValue.h"
29 #include "llvm/IR/GlobalVariable.h"
30 #include "llvm/IR/Instruction.h"
31 #include "llvm/IR/Instructions.h"
32 #include "llvm/IR/Metadata.h"
33 #include "llvm/IR/Module.h"
34 #include "llvm/IR/Type.h"
35 #include "llvm/IR/Use.h"
36 #include "llvm/IR/UseListOrder.h"
37 #include "llvm/IR/User.h"
38 #include "llvm/IR/Value.h"
40 #include "llvm/Support/Casting.h"
41 #include "llvm/Support/Compiler.h"
42 #include "llvm/Support/Debug.h"
45 #include <algorithm>
46 #include <cassert>
47 #include <cstddef>
48 #include <iterator>
49 #include <tuple>
50 #include <utility>
51 #include <vector>
52 
53 using namespace llvm;
54 
55 namespace {
56 
57 struct OrderMap {
59  unsigned LastGlobalConstantID = 0;
60  unsigned LastGlobalValueID = 0;
61 
62  OrderMap() = default;
63 
64  bool isGlobalConstant(unsigned ID) const {
65  return ID <= LastGlobalConstantID;
66  }
67 
68  bool isGlobalValue(unsigned ID) const {
69  return ID <= LastGlobalValueID && !isGlobalConstant(ID);
70  }
71 
72  unsigned size() const { return IDs.size(); }
73  std::pair<unsigned, bool> &operator[](const Value *V) { return IDs[V]; }
74 
75  std::pair<unsigned, bool> lookup(const Value *V) const {
76  return IDs.lookup(V);
77  }
78 
79  void index(const Value *V) {
80  // Explicitly sequence get-size and insert-value operations to avoid UB.
81  unsigned ID = IDs.size() + 1;
82  IDs[V].first = ID;
83  }
84 };
85 
86 } // end anonymous namespace
87 
88 static void orderValue(const Value *V, OrderMap &OM) {
89  if (OM.lookup(V).first)
90  return;
91 
92  if (const Constant *C = dyn_cast<Constant>(V))
93  if (C->getNumOperands() && !isa<GlobalValue>(C))
94  for (const Value *Op : C->operands())
95  if (!isa<BasicBlock>(Op) && !isa<GlobalValue>(Op))
96  orderValue(Op, OM);
97 
98  // Note: we cannot cache this lookup above, since inserting into the map
99  // changes the map's size, and thus affects the other IDs.
100  OM.index(V);
101 }
102 
103 static OrderMap orderModule(const Module &M) {
104  // This needs to match the order used by ValueEnumerator::ValueEnumerator()
105  // and ValueEnumerator::incorporateFunction().
106  OrderMap OM;
107 
108  // In the reader, initializers of GlobalValues are set *after* all the
109  // globals have been read. Rather than awkwardly modeling this behaviour
110  // directly in predictValueUseListOrderImpl(), just assign IDs to
111  // initializers of GlobalValues before GlobalValues themselves to model this
112  // implicitly.
113  for (const GlobalVariable &G : M.globals())
114  if (G.hasInitializer())
115  if (!isa<GlobalValue>(G.getInitializer()))
116  orderValue(G.getInitializer(), OM);
117  for (const GlobalAlias &A : M.aliases())
118  if (!isa<GlobalValue>(A.getAliasee()))
119  orderValue(A.getAliasee(), OM);
120  for (const GlobalIFunc &I : M.ifuncs())
121  if (!isa<GlobalValue>(I.getResolver()))
122  orderValue(I.getResolver(), OM);
123  for (const Function &F : M) {
124  for (const Use &U : F.operands())
125  if (!isa<GlobalValue>(U.get()))
126  orderValue(U.get(), OM);
127  }
128  OM.LastGlobalConstantID = OM.size();
129 
130  // Initializers of GlobalValues are processed in
131  // BitcodeReader::ResolveGlobalAndAliasInits(). Match the order there rather
132  // than ValueEnumerator, and match the code in predictValueUseListOrderImpl()
133  // by giving IDs in reverse order.
134  //
135  // Since GlobalValues never reference each other directly (just through
136  // initializers), their relative IDs only matter for determining order of
137  // uses in their initializers.
138  for (const Function &F : M)
139  orderValue(&F, OM);
140  for (const GlobalAlias &A : M.aliases())
141  orderValue(&A, OM);
142  for (const GlobalIFunc &I : M.ifuncs())
143  orderValue(&I, OM);
144  for (const GlobalVariable &G : M.globals())
145  orderValue(&G, OM);
146  OM.LastGlobalValueID = OM.size();
147 
148  for (const Function &F : M) {
149  if (F.isDeclaration())
150  continue;
151  // Here we need to match the union of ValueEnumerator::incorporateFunction()
152  // and WriteFunction(). Basic blocks are implicitly declared before
153  // anything else (by declaring their size).
154  for (const BasicBlock &BB : F)
155  orderValue(&BB, OM);
156  for (const Argument &A : F.args())
157  orderValue(&A, OM);
158  for (const BasicBlock &BB : F)
159  for (const Instruction &I : BB)
160  for (const Value *Op : I.operands())
161  if ((isa<Constant>(*Op) && !isa<GlobalValue>(*Op)) ||
162  isa<InlineAsm>(*Op))
163  orderValue(Op, OM);
164  for (const BasicBlock &BB : F)
165  for (const Instruction &I : BB)
166  orderValue(&I, OM);
167  }
168  return OM;
169 }
170 
171 static void predictValueUseListOrderImpl(const Value *V, const Function *F,
172  unsigned ID, const OrderMap &OM,
173  UseListOrderStack &Stack) {
174  // Predict use-list order for this one.
175  using Entry = std::pair<const Use *, unsigned>;
177  for (const Use &U : V->uses())
178  // Check if this user will be serialized.
179  if (OM.lookup(U.getUser()).first)
180  List.push_back(std::make_pair(&U, List.size()));
181 
182  if (List.size() < 2)
183  // We may have lost some users.
184  return;
185 
186  bool IsGlobalValue = OM.isGlobalValue(ID);
187  llvm::sort(List.begin(), List.end(), [&](const Entry &L, const Entry &R) {
188  const Use *LU = L.first;
189  const Use *RU = R.first;
190  if (LU == RU)
191  return false;
192 
193  auto LID = OM.lookup(LU->getUser()).first;
194  auto RID = OM.lookup(RU->getUser()).first;
195 
196  // Global values are processed in reverse order.
197  //
198  // Moreover, initializers of GlobalValues are set *after* all the globals
199  // have been read (despite having earlier IDs). Rather than awkwardly
200  // modeling this behaviour here, orderModule() has assigned IDs to
201  // initializers of GlobalValues before GlobalValues themselves.
202  if (OM.isGlobalValue(LID) && OM.isGlobalValue(RID))
203  return LID < RID;
204 
205  // If ID is 4, then expect: 7 6 5 1 2 3.
206  if (LID < RID) {
207  if (RID <= ID)
208  if (!IsGlobalValue) // GlobalValue uses don't get reversed.
209  return true;
210  return false;
211  }
212  if (RID < LID) {
213  if (LID <= ID)
214  if (!IsGlobalValue) // GlobalValue uses don't get reversed.
215  return false;
216  return true;
217  }
218 
219  // LID and RID are equal, so we have different operands of the same user.
220  // Assume operands are added in order for all instructions.
221  if (LID <= ID)
222  if (!IsGlobalValue) // GlobalValue uses don't get reversed.
223  return LU->getOperandNo() < RU->getOperandNo();
224  return LU->getOperandNo() > RU->getOperandNo();
225  });
226 
227  if (std::is_sorted(
228  List.begin(), List.end(),
229  [](const Entry &L, const Entry &R) { return L.second < R.second; }))
230  // Order is already correct.
231  return;
232 
233  // Store the shuffle.
234  Stack.emplace_back(V, F, List.size());
235  assert(List.size() == Stack.back().Shuffle.size() && "Wrong size");
236  for (size_t I = 0, E = List.size(); I != E; ++I)
237  Stack.back().Shuffle[I] = List[I].second;
238 }
239 
240 static void predictValueUseListOrder(const Value *V, const Function *F,
241  OrderMap &OM, UseListOrderStack &Stack) {
242  auto &IDPair = OM[V];
243  assert(IDPair.first && "Unmapped value");
244  if (IDPair.second)
245  // Already predicted.
246  return;
247 
248  // Do the actual prediction.
249  IDPair.second = true;
250  if (!V->use_empty() && std::next(V->use_begin()) != V->use_end())
251  predictValueUseListOrderImpl(V, F, IDPair.first, OM, Stack);
252 
253  // Recursive descent into constants.
254  if (const Constant *C = dyn_cast<Constant>(V))
255  if (C->getNumOperands()) // Visit GlobalValues.
256  for (const Value *Op : C->operands())
257  if (isa<Constant>(Op)) // Visit GlobalValues.
258  predictValueUseListOrder(Op, F, OM, Stack);
259 }
260 
262  OrderMap OM = orderModule(M);
263 
264  // Use-list orders need to be serialized after all the users have been added
265  // to a value, or else the shuffles will be incomplete. Store them per
266  // function in a stack.
267  //
268  // Aside from function order, the order of values doesn't matter much here.
269  UseListOrderStack Stack;
270 
271  // We want to visit the functions backward now so we can list function-local
272  // constants in the last Function they're used in. Module-level constants
273  // have already been visited above.
274  for (auto I = M.rbegin(), E = M.rend(); I != E; ++I) {
275  const Function &F = *I;
276  if (F.isDeclaration())
277  continue;
278  for (const BasicBlock &BB : F)
279  predictValueUseListOrder(&BB, &F, OM, Stack);
280  for (const Argument &A : F.args())
281  predictValueUseListOrder(&A, &F, OM, Stack);
282  for (const BasicBlock &BB : F)
283  for (const Instruction &I : BB)
284  for (const Value *Op : I.operands())
285  if (isa<Constant>(*Op) || isa<InlineAsm>(*Op)) // Visit GlobalValues.
286  predictValueUseListOrder(Op, &F, OM, Stack);
287  for (const BasicBlock &BB : F)
288  for (const Instruction &I : BB)
289  predictValueUseListOrder(&I, &F, OM, Stack);
290  }
291 
292  // Visit globals last, since the module-level use-list block will be seen
293  // before the function bodies are processed.
294  for (const GlobalVariable &G : M.globals())
295  predictValueUseListOrder(&G, nullptr, OM, Stack);
296  for (const Function &F : M)
297  predictValueUseListOrder(&F, nullptr, OM, Stack);
298  for (const GlobalAlias &A : M.aliases())
299  predictValueUseListOrder(&A, nullptr, OM, Stack);
300  for (const GlobalIFunc &I : M.ifuncs())
301  predictValueUseListOrder(&I, nullptr, OM, Stack);
302  for (const GlobalVariable &G : M.globals())
303  if (G.hasInitializer())
304  predictValueUseListOrder(G.getInitializer(), nullptr, OM, Stack);
305  for (const GlobalAlias &A : M.aliases())
306  predictValueUseListOrder(A.getAliasee(), nullptr, OM, Stack);
307  for (const GlobalIFunc &I : M.ifuncs())
308  predictValueUseListOrder(I.getResolver(), nullptr, OM, Stack);
309  for (const Function &F : M) {
310  for (const Use &U : F.operands())
311  predictValueUseListOrder(U.get(), nullptr, OM, Stack);
312  }
313 
314  return Stack;
315 }
316 
317 static bool isIntOrIntVectorValue(const std::pair<const Value*, unsigned> &V) {
318  return V.first->getType()->isIntOrIntVectorTy();
319 }
320 
322  bool ShouldPreserveUseListOrder)
323  : ShouldPreserveUseListOrder(ShouldPreserveUseListOrder) {
324  if (ShouldPreserveUseListOrder)
326 
327  // Enumerate the global variables.
328  for (const GlobalVariable &GV : M.globals())
329  EnumerateValue(&GV);
330 
331  // Enumerate the functions.
332  for (const Function & F : M) {
333  EnumerateValue(&F);
334  EnumerateAttributes(F.getAttributes());
335  }
336 
337  // Enumerate the aliases.
338  for (const GlobalAlias &GA : M.aliases())
339  EnumerateValue(&GA);
340 
341  // Enumerate the ifuncs.
342  for (const GlobalIFunc &GIF : M.ifuncs())
343  EnumerateValue(&GIF);
344 
345  // Remember what is the cutoff between globalvalue's and other constants.
346  unsigned FirstConstant = Values.size();
347 
348  // Enumerate the global variable initializers and attributes.
349  for (const GlobalVariable &GV : M.globals()) {
350  if (GV.hasInitializer())
351  EnumerateValue(GV.getInitializer());
352  if (GV.hasAttributes())
353  EnumerateAttributes(GV.getAttributesAsList(AttributeList::FunctionIndex));
354  }
355 
356  // Enumerate the aliasees.
357  for (const GlobalAlias &GA : M.aliases())
358  EnumerateValue(GA.getAliasee());
359 
360  // Enumerate the ifunc resolvers.
361  for (const GlobalIFunc &GIF : M.ifuncs())
362  EnumerateValue(GIF.getResolver());
363 
364  // Enumerate any optional Function data.
365  for (const Function &F : M)
366  for (const Use &U : F.operands())
367  EnumerateValue(U.get());
368 
369  // Enumerate the metadata type.
370  //
371  // TODO: Move this to ValueEnumerator::EnumerateOperandType() once bitcode
372  // only encodes the metadata type when it's used as a value.
373  EnumerateType(Type::getMetadataTy(M.getContext()));
374 
375  // Insert constants and metadata that are named at module level into the slot
376  // pool so that the module symbol table can refer to them...
377  EnumerateValueSymbolTable(M.getValueSymbolTable());
378  EnumerateNamedMetadata(M);
379 
381  for (const GlobalVariable &GV : M.globals()) {
382  MDs.clear();
383  GV.getAllMetadata(MDs);
384  for (const auto &I : MDs)
385  // FIXME: Pass GV to EnumerateMetadata and arrange for the bitcode writer
386  // to write metadata to the global variable's own metadata block
387  // (PR28134).
388  EnumerateMetadata(nullptr, I.second);
389  }
390 
391  // Enumerate types used by function bodies and argument lists.
392  for (const Function &F : M) {
393  for (const Argument &A : F.args())
394  EnumerateType(A.getType());
395 
396  // Enumerate metadata attached to this function.
397  MDs.clear();
398  F.getAllMetadata(MDs);
399  for (const auto &I : MDs)
400  EnumerateMetadata(F.isDeclaration() ? nullptr : &F, I.second);
401 
402  for (const BasicBlock &BB : F)
403  for (const Instruction &I : BB) {
404  for (const Use &Op : I.operands()) {
405  auto *MD = dyn_cast<MetadataAsValue>(&Op);
406  if (!MD) {
407  EnumerateOperandType(Op);
408  continue;
409  }
410 
411  // Local metadata is enumerated during function-incorporation.
412  if (isa<LocalAsMetadata>(MD->getMetadata()))
413  continue;
414 
415  EnumerateMetadata(&F, MD->getMetadata());
416  }
417  EnumerateType(I.getType());
418  if (const CallInst *CI = dyn_cast<CallInst>(&I))
419  EnumerateAttributes(CI->getAttributes());
420  else if (const InvokeInst *II = dyn_cast<InvokeInst>(&I))
421  EnumerateAttributes(II->getAttributes());
422 
423  // Enumerate metadata attached with this instruction.
424  MDs.clear();
425  I.getAllMetadataOtherThanDebugLoc(MDs);
426  for (unsigned i = 0, e = MDs.size(); i != e; ++i)
427  EnumerateMetadata(&F, MDs[i].second);
428 
429  // Don't enumerate the location directly -- it has a special record
430  // type -- but enumerate its operands.
431  if (DILocation *L = I.getDebugLoc())
432  for (const Metadata *Op : L->operands())
433  EnumerateMetadata(&F, Op);
434  }
435  }
436 
437  // Optimize constant ordering.
438  OptimizeConstants(FirstConstant, Values.size());
439 
440  // Organize metadata ordering.
441  organizeMetadata();
442 }
443 
444 unsigned ValueEnumerator::getInstructionID(const Instruction *Inst) const {
445  InstructionMapType::const_iterator I = InstructionMap.find(Inst);
446  assert(I != InstructionMap.end() && "Instruction is not mapped!");
447  return I->second;
448 }
449 
450 unsigned ValueEnumerator::getComdatID(const Comdat *C) const {
451  unsigned ComdatID = Comdats.idFor(C);
452  assert(ComdatID && "Comdat not found!");
453  return ComdatID;
454 }
455 
457  InstructionMap[I] = InstructionCount++;
458 }
459 
460 unsigned ValueEnumerator::getValueID(const Value *V) const {
461  if (auto *MD = dyn_cast<MetadataAsValue>(V))
462  return getMetadataID(MD->getMetadata());
463 
465  assert(I != ValueMap.end() && "Value not in slotcalculator!");
466  return I->second-1;
467 }
468 
469 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
471  print(dbgs(), ValueMap, "Default");
472  dbgs() << '\n';
473  print(dbgs(), MetadataMap, "MetaData");
474  dbgs() << '\n';
475 }
476 #endif
477 
479  const char *Name) const {
480  OS << "Map Name: " << Name << "\n";
481  OS << "Size: " << Map.size() << "\n";
482  for (ValueMapType::const_iterator I = Map.begin(),
483  E = Map.end(); I != E; ++I) {
484  const Value *V = I->first;
485  if (V->hasName())
486  OS << "Value: " << V->getName();
487  else
488  OS << "Value: [null]\n";
489  V->print(errs());
490  errs() << '\n';
491 
492  OS << " Uses(" << V->getNumUses() << "):";
493  for (const Use &U : V->uses()) {
494  if (&U != &*V->use_begin())
495  OS << ",";
496  if(U->hasName())
497  OS << " " << U->getName();
498  else
499  OS << " [null]";
500 
501  }
502  OS << "\n\n";
503  }
504 }
505 
507  const char *Name) const {
508  OS << "Map Name: " << Name << "\n";
509  OS << "Size: " << Map.size() << "\n";
510  for (auto I = Map.begin(), E = Map.end(); I != E; ++I) {
511  const Metadata *MD = I->first;
512  OS << "Metadata: slot = " << I->second.ID << "\n";
513  OS << "Metadata: function = " << I->second.F << "\n";
514  MD->print(OS);
515  OS << "\n";
516  }
517 }
518 
519 /// OptimizeConstants - Reorder constant pool for denser encoding.
520 void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) {
521  if (CstStart == CstEnd || CstStart+1 == CstEnd) return;
522 
523  if (ShouldPreserveUseListOrder)
524  // Optimizing constants makes the use-list order difficult to predict.
525  // Disable it for now when trying to preserve the order.
526  return;
527 
528  std::stable_sort(Values.begin() + CstStart, Values.begin() + CstEnd,
529  [this](const std::pair<const Value *, unsigned> &LHS,
530  const std::pair<const Value *, unsigned> &RHS) {
531  // Sort by plane.
532  if (LHS.first->getType() != RHS.first->getType())
533  return getTypeID(LHS.first->getType()) < getTypeID(RHS.first->getType());
534  // Then by frequency.
535  return LHS.second > RHS.second;
536  });
537 
538  // Ensure that integer and vector of integer constants are at the start of the
539  // constant pool. This is important so that GEP structure indices come before
540  // gep constant exprs.
541  std::stable_partition(Values.begin() + CstStart, Values.begin() + CstEnd,
543 
544  // Rebuild the modified portion of ValueMap.
545  for (; CstStart != CstEnd; ++CstStart)
546  ValueMap[Values[CstStart].first] = CstStart+1;
547 }
548 
549 /// EnumerateValueSymbolTable - Insert all of the values in the specified symbol
550 /// table into the values table.
551 void ValueEnumerator::EnumerateValueSymbolTable(const ValueSymbolTable &VST) {
552  for (ValueSymbolTable::const_iterator VI = VST.begin(), VE = VST.end();
553  VI != VE; ++VI)
554  EnumerateValue(VI->getValue());
555 }
556 
557 /// Insert all of the values referenced by named metadata in the specified
558 /// module.
559 void ValueEnumerator::EnumerateNamedMetadata(const Module &M) {
560  for (const auto &I : M.named_metadata())
561  EnumerateNamedMDNode(&I);
562 }
563 
564 void ValueEnumerator::EnumerateNamedMDNode(const NamedMDNode *MD) {
565  for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i)
566  EnumerateMetadata(nullptr, MD->getOperand(i));
567 }
568 
569 unsigned ValueEnumerator::getMetadataFunctionID(const Function *F) const {
570  return F ? getValueID(F) + 1 : 0;
571 }
572 
573 void ValueEnumerator::EnumerateMetadata(const Function *F, const Metadata *MD) {
574  EnumerateMetadata(getMetadataFunctionID(F), MD);
575 }
576 
577 void ValueEnumerator::EnumerateFunctionLocalMetadata(
578  const Function &F, const LocalAsMetadata *Local) {
579  EnumerateFunctionLocalMetadata(getMetadataFunctionID(&F), Local);
580 }
581 
582 void ValueEnumerator::dropFunctionFromMetadata(
583  MetadataMapType::value_type &FirstMD) {
585  auto push = [&Worklist](MetadataMapType::value_type &MD) {
586  auto &Entry = MD.second;
587 
588  // Nothing to do if this metadata isn't tagged.
589  if (!Entry.F)
590  return;
591 
592  // Drop the function tag.
593  Entry.F = 0;
594 
595  // If this is has an ID and is an MDNode, then its operands have entries as
596  // well. We need to drop the function from them too.
597  if (Entry.ID)
598  if (auto *N = dyn_cast<MDNode>(MD.first))
599  Worklist.push_back(N);
600  };
601  push(FirstMD);
602  while (!Worklist.empty())
603  for (const Metadata *Op : Worklist.pop_back_val()->operands()) {
604  if (!Op)
605  continue;
606  auto MD = MetadataMap.find(Op);
607  if (MD != MetadataMap.end())
608  push(*MD);
609  }
610 }
611 
612 void ValueEnumerator::EnumerateMetadata(unsigned F, const Metadata *MD) {
613  // It's vital for reader efficiency that uniqued subgraphs are done in
614  // post-order; it's expensive when their operands have forward references.
615  // If a distinct node is referenced from a uniqued node, it'll be delayed
616  // until the uniqued subgraph has been completely traversed.
617  SmallVector<const MDNode *, 32> DelayedDistinctNodes;
618 
619  // Start by enumerating MD, and then work through its transitive operands in
620  // post-order. This requires a depth-first search.
622  if (const MDNode *N = enumerateMetadataImpl(F, MD))
623  Worklist.push_back(std::make_pair(N, N->op_begin()));
624 
625  while (!Worklist.empty()) {
626  const MDNode *N = Worklist.back().first;
627 
628  // Enumerate operands until we hit a new node. We need to traverse these
629  // nodes' operands before visiting the rest of N's operands.
631  Worklist.back().second, N->op_end(),
632  [&](const Metadata *MD) { return enumerateMetadataImpl(F, MD); });
633  if (I != N->op_end()) {
634  auto *Op = cast<MDNode>(*I);
635  Worklist.back().second = ++I;
636 
637  // Delay traversing Op if it's a distinct node and N is uniqued.
638  if (Op->isDistinct() && !N->isDistinct())
639  DelayedDistinctNodes.push_back(Op);
640  else
641  Worklist.push_back(std::make_pair(Op, Op->op_begin()));
642  continue;
643  }
644 
645  // All the operands have been visited. Now assign an ID.
646  Worklist.pop_back();
647  MDs.push_back(N);
648  MetadataMap[N].ID = MDs.size();
649 
650  // Flush out any delayed distinct nodes; these are all the distinct nodes
651  // that are leaves in last uniqued subgraph.
652  if (Worklist.empty() || Worklist.back().first->isDistinct()) {
653  for (const MDNode *N : DelayedDistinctNodes)
654  Worklist.push_back(std::make_pair(N, N->op_begin()));
655  DelayedDistinctNodes.clear();
656  }
657  }
658 }
659 
660 const MDNode *ValueEnumerator::enumerateMetadataImpl(unsigned F, const Metadata *MD) {
661  if (!MD)
662  return nullptr;
663 
664  assert(
665  (isa<MDNode>(MD) || isa<MDString>(MD) || isa<ConstantAsMetadata>(MD)) &&
666  "Invalid metadata kind");
667 
668  auto Insertion = MetadataMap.insert(std::make_pair(MD, MDIndex(F)));
669  MDIndex &Entry = Insertion.first->second;
670  if (!Insertion.second) {
671  // Already mapped. If F doesn't match the function tag, drop it.
672  if (Entry.hasDifferentFunction(F))
673  dropFunctionFromMetadata(*Insertion.first);
674  return nullptr;
675  }
676 
677  // Don't assign IDs to metadata nodes.
678  if (auto *N = dyn_cast<MDNode>(MD))
679  return N;
680 
681  // Save the metadata.
682  MDs.push_back(MD);
683  Entry.ID = MDs.size();
684 
685  // Enumerate the constant, if any.
686  if (auto *C = dyn_cast<ConstantAsMetadata>(MD))
687  EnumerateValue(C->getValue());
688 
689  return nullptr;
690 }
691 
692 /// EnumerateFunctionLocalMetadataa - Incorporate function-local metadata
693 /// information reachable from the metadata.
694 void ValueEnumerator::EnumerateFunctionLocalMetadata(
695  unsigned F, const LocalAsMetadata *Local) {
696  assert(F && "Expected a function");
697 
698  // Check to see if it's already in!
699  MDIndex &Index = MetadataMap[Local];
700  if (Index.ID) {
701  assert(Index.F == F && "Expected the same function");
702  return;
703  }
704 
705  MDs.push_back(Local);
706  Index.F = F;
707  Index.ID = MDs.size();
708 
709  EnumerateValue(Local->getValue());
710 }
711 
712 static unsigned getMetadataTypeOrder(const Metadata *MD) {
713  // Strings are emitted in bulk and must come first.
714  if (isa<MDString>(MD))
715  return 0;
716 
717  // ConstantAsMetadata doesn't reference anything. We may as well shuffle it
718  // to the front since we can detect it.
719  auto *N = dyn_cast<MDNode>(MD);
720  if (!N)
721  return 1;
722 
723  // The reader is fast forward references for distinct node operands, but slow
724  // when uniqued operands are unresolved.
725  return N->isDistinct() ? 2 : 3;
726 }
727 
728 void ValueEnumerator::organizeMetadata() {
729  assert(MetadataMap.size() == MDs.size() &&
730  "Metadata map and vector out of sync");
731 
732  if (MDs.empty())
733  return;
734 
735  // Copy out the index information from MetadataMap in order to choose a new
736  // order.
738  Order.reserve(MetadataMap.size());
739  for (const Metadata *MD : MDs)
740  Order.push_back(MetadataMap.lookup(MD));
741 
742  // Partition:
743  // - by function, then
744  // - by isa<MDString>
745  // and then sort by the original/current ID. Since the IDs are guaranteed to
746  // be unique, the result of std::sort will be deterministic. There's no need
747  // for std::stable_sort.
748  llvm::sort(Order.begin(), Order.end(), [this](MDIndex LHS, MDIndex RHS) {
749  return std::make_tuple(LHS.F, getMetadataTypeOrder(LHS.get(MDs)), LHS.ID) <
750  std::make_tuple(RHS.F, getMetadataTypeOrder(RHS.get(MDs)), RHS.ID);
751  });
752 
753  // Rebuild MDs, index the metadata ranges for each function in FunctionMDs,
754  // and fix up MetadataMap.
755  std::vector<const Metadata *> OldMDs = std::move(MDs);
756  MDs.reserve(OldMDs.size());
757  for (unsigned I = 0, E = Order.size(); I != E && !Order[I].F; ++I) {
758  auto *MD = Order[I].get(OldMDs);
759  MDs.push_back(MD);
760  MetadataMap[MD].ID = I + 1;
761  if (isa<MDString>(MD))
762  ++NumMDStrings;
763  }
764 
765  // Return early if there's nothing for the functions.
766  if (MDs.size() == Order.size())
767  return;
768 
769  // Build the function metadata ranges.
770  MDRange R;
771  FunctionMDs.reserve(OldMDs.size());
772  unsigned PrevF = 0;
773  for (unsigned I = MDs.size(), E = Order.size(), ID = MDs.size(); I != E;
774  ++I) {
775  unsigned F = Order[I].F;
776  if (!PrevF) {
777  PrevF = F;
778  } else if (PrevF != F) {
779  R.Last = FunctionMDs.size();
780  std::swap(R, FunctionMDInfo[PrevF]);
781  R.First = FunctionMDs.size();
782 
783  ID = MDs.size();
784  PrevF = F;
785  }
786 
787  auto *MD = Order[I].get(OldMDs);
788  FunctionMDs.push_back(MD);
789  MetadataMap[MD].ID = ++ID;
790  if (isa<MDString>(MD))
791  ++R.NumStrings;
792  }
793  R.Last = FunctionMDs.size();
794  FunctionMDInfo[PrevF] = R;
795 }
796 
797 void ValueEnumerator::incorporateFunctionMetadata(const Function &F) {
798  NumModuleMDs = MDs.size();
799 
800  auto R = FunctionMDInfo.lookup(getValueID(&F) + 1);
801  NumMDStrings = R.NumStrings;
802  MDs.insert(MDs.end(), FunctionMDs.begin() + R.First,
803  FunctionMDs.begin() + R.Last);
804 }
805 
806 void ValueEnumerator::EnumerateValue(const Value *V) {
807  assert(!V->getType()->isVoidTy() && "Can't insert void values!");
808  assert(!isa<MetadataAsValue>(V) && "EnumerateValue doesn't handle Metadata!");
809 
810  // Check to see if it's already in!
811  unsigned &ValueID = ValueMap[V];
812  if (ValueID) {
813  // Increment use count.
814  Values[ValueID-1].second++;
815  return;
816  }
817 
818  if (auto *GO = dyn_cast<GlobalObject>(V))
819  if (const Comdat *C = GO->getComdat())
820  Comdats.insert(C);
821 
822  // Enumerate the type of this value.
823  EnumerateType(V->getType());
824 
825  if (const Constant *C = dyn_cast<Constant>(V)) {
826  if (isa<GlobalValue>(C)) {
827  // Initializers for globals are handled explicitly elsewhere.
828  } else if (C->getNumOperands()) {
829  // If a constant has operands, enumerate them. This makes sure that if a
830  // constant has uses (for example an array of const ints), that they are
831  // inserted also.
832 
833  // We prefer to enumerate them with values before we enumerate the user
834  // itself. This makes it more likely that we can avoid forward references
835  // in the reader. We know that there can be no cycles in the constants
836  // graph that don't go through a global variable.
837  for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
838  I != E; ++I)
839  if (!isa<BasicBlock>(*I)) // Don't enumerate BB operand to BlockAddress.
840  EnumerateValue(*I);
841 
842  // Finally, add the value. Doing this could make the ValueID reference be
843  // dangling, don't reuse it.
844  Values.push_back(std::make_pair(V, 1U));
845  ValueMap[V] = Values.size();
846  return;
847  }
848  }
849 
850  // Add the value.
851  Values.push_back(std::make_pair(V, 1U));
852  ValueID = Values.size();
853 }
854 
855 
856 void ValueEnumerator::EnumerateType(Type *Ty) {
857  unsigned *TypeID = &TypeMap[Ty];
858 
859  // We've already seen this type.
860  if (*TypeID)
861  return;
862 
863  // If it is a non-anonymous struct, mark the type as being visited so that we
864  // don't recursively visit it. This is safe because we allow forward
865  // references of these in the bitcode reader.
866  if (StructType *STy = dyn_cast<StructType>(Ty))
867  if (!STy->isLiteral())
868  *TypeID = ~0U;
869 
870  // Enumerate all of the subtypes before we enumerate this type. This ensures
871  // that the type will be enumerated in an order that can be directly built.
872  for (Type *SubTy : Ty->subtypes())
873  EnumerateType(SubTy);
874 
875  // Refresh the TypeID pointer in case the table rehashed.
876  TypeID = &TypeMap[Ty];
877 
878  // Check to see if we got the pointer another way. This can happen when
879  // enumerating recursive types that hit the base case deeper than they start.
880  //
881  // If this is actually a struct that we are treating as forward ref'able,
882  // then emit the definition now that all of its contents are available.
883  if (*TypeID && *TypeID != ~0U)
884  return;
885 
886  // Add this type now that its contents are all happily enumerated.
887  Types.push_back(Ty);
888 
889  *TypeID = Types.size();
890 }
891 
892 // Enumerate the types for the specified value. If the value is a constant,
893 // walk through it, enumerating the types of the constant.
894 void ValueEnumerator::EnumerateOperandType(const Value *V) {
895  EnumerateType(V->getType());
896 
897  assert(!isa<MetadataAsValue>(V) && "Unexpected metadata operand");
898 
899  const Constant *C = dyn_cast<Constant>(V);
900  if (!C)
901  return;
902 
903  // If this constant is already enumerated, ignore it, we know its type must
904  // be enumerated.
905  if (ValueMap.count(C))
906  return;
907 
908  // This constant may have operands, make sure to enumerate the types in
909  // them.
910  for (const Value *Op : C->operands()) {
911  // Don't enumerate basic blocks here, this happens as operands to
912  // blockaddress.
913  if (isa<BasicBlock>(Op))
914  continue;
915 
916  EnumerateOperandType(Op);
917  }
918 }
919 
920 void ValueEnumerator::EnumerateAttributes(AttributeList PAL) {
921  if (PAL.isEmpty()) return; // null is always 0.
922 
923  // Do a lookup.
924  unsigned &Entry = AttributeListMap[PAL];
925  if (Entry == 0) {
926  // Never saw this before, add it.
927  AttributeLists.push_back(PAL);
928  Entry = AttributeLists.size();
929  }
930 
931  // Do lookups for all attribute groups.
932  for (unsigned i = PAL.index_begin(), e = PAL.index_end(); i != e; ++i) {
933  AttributeSet AS = PAL.getAttributes(i);
934  if (!AS.hasAttributes())
935  continue;
936  IndexAndAttrSet Pair = {i, AS};
937  unsigned &Entry = AttributeGroupMap[Pair];
938  if (Entry == 0) {
939  AttributeGroups.push_back(Pair);
940  Entry = AttributeGroups.size();
941  }
942  }
943 }
944 
946  InstructionCount = 0;
947  NumModuleValues = Values.size();
948 
949  // Add global metadata to the function block. This doesn't include
950  // LocalAsMetadata.
951  incorporateFunctionMetadata(F);
952 
953  // Adding function arguments to the value table.
954  for (const auto &I : F.args())
955  EnumerateValue(&I);
956 
957  FirstFuncConstantID = Values.size();
958 
959  // Add all function-level constants to the value table.
960  for (const BasicBlock &BB : F) {
961  for (const Instruction &I : BB)
962  for (const Use &OI : I.operands()) {
963  if ((isa<Constant>(OI) && !isa<GlobalValue>(OI)) || isa<InlineAsm>(OI))
964  EnumerateValue(OI);
965  }
966  BasicBlocks.push_back(&BB);
967  ValueMap[&BB] = BasicBlocks.size();
968  }
969 
970  // Optimize the constant layout.
971  OptimizeConstants(FirstFuncConstantID, Values.size());
972 
973  // Add the function's parameter attributes so they are available for use in
974  // the function's instruction.
975  EnumerateAttributes(F.getAttributes());
976 
977  FirstInstID = Values.size();
978 
979  SmallVector<LocalAsMetadata *, 8> FnLocalMDVector;
980  // Add all of the instructions.
981  for (const BasicBlock &BB : F) {
982  for (const Instruction &I : BB) {
983  for (const Use &OI : I.operands()) {
984  if (auto *MD = dyn_cast<MetadataAsValue>(&OI))
985  if (auto *Local = dyn_cast<LocalAsMetadata>(MD->getMetadata()))
986  // Enumerate metadata after the instructions they might refer to.
987  FnLocalMDVector.push_back(Local);
988  }
989 
990  if (!I.getType()->isVoidTy())
991  EnumerateValue(&I);
992  }
993  }
994 
995  // Add all of the function-local metadata.
996  for (unsigned i = 0, e = FnLocalMDVector.size(); i != e; ++i) {
997  // At this point, every local values have been incorporated, we shouldn't
998  // have a metadata operand that references a value that hasn't been seen.
999  assert(ValueMap.count(FnLocalMDVector[i]->getValue()) &&
1000  "Missing value for metadata operand");
1001  EnumerateFunctionLocalMetadata(F, FnLocalMDVector[i]);
1002  }
1003 }
1004 
1006  /// Remove purged values from the ValueMap.
1007  for (unsigned i = NumModuleValues, e = Values.size(); i != e; ++i)
1008  ValueMap.erase(Values[i].first);
1009  for (unsigned i = NumModuleMDs, e = MDs.size(); i != e; ++i)
1010  MetadataMap.erase(MDs[i]);
1011  for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i)
1012  ValueMap.erase(BasicBlocks[i]);
1013 
1014  Values.resize(NumModuleValues);
1015  MDs.resize(NumModuleMDs);
1016  BasicBlocks.clear();
1017  NumMDStrings = 0;
1018 }
1019 
1022  unsigned Counter = 0;
1023  for (const BasicBlock &BB : *F)
1024  IDMap[&BB] = ++Counter;
1025 }
1026 
1027 /// getGlobalBasicBlockID - This returns the function-specific ID for the
1028 /// specified basic block. This is relatively expensive information, so it
1029 /// should only be used by rare constructs such as address-of-label.
1031  unsigned &Idx = GlobalBasicBlockIDs[BB];
1032  if (Idx != 0)
1033  return Idx-1;
1034 
1035  IncorporateFunctionInfoGlobalBBIDs(BB->getParent(), GlobalBasicBlockIDs);
1036  return getGlobalBasicBlockID(BB);
1037 }
1038 
1040  return Log2_32_Ceil(getTypes().size() + 1);
1041 }
uint64_t CallInst * C
use_iterator use_end()
Definition: Value.h:346
unsigned Log2_32_Ceil(uint32_t Value)
Return the ceil log base 2 of the specified value, 32 if the value is zero.
Definition: MathExtras.h:552
Tracking metadata reference owned by Metadata.
Definition: Metadata.h:709
This class provides a symbol table of name/value pairs.
ArrayRef< Type * > subtypes() const
Definition: Type.h:317
iterator_range< use_iterator > uses()
Definition: Value.h:354
raw_ostream & errs()
This returns a reference to a raw_ostream for standard error.
bool isDistinct() const
Definition: Metadata.h:941
static unsigned getMetadataTypeOrder(const Metadata *MD)
This class represents an incoming formal argument to a Function.
Definition: Argument.h:30
iterator begin()
Get an iterator that from the beginning of the symbol table.
unsigned getValueID(const Value *V) const
MDNode * getOperand(unsigned i) const
Definition: Metadata.cpp:1081
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
static void predictValueUseListOrder(const Value *V, const Function *F, OrderMap &OM, UseListOrderStack &Stack)
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:63
LLVM_ATTRIBUTE_ALWAYS_INLINE size_type size() const
Definition: SmallVector.h:137
std::pair< unsigned, AttributeSet > IndexAndAttrSet
Attribute groups as encoded in bitcode are almost AttributeSets, but they include the AttributeList i...
This class represents a function call, abstracting a target machine&#39;s calling convention.
This file contains the declarations for metadata subclasses.
void setInstructionID(const Instruction *I)
unsigned second
Metadata node.
Definition: Metadata.h:862
F(f)
#define LLVM_DUMP_METHOD
Mark debug helper function definitions like dump() that should not be stripped from debug builds...
Definition: Compiler.h:452
static Type * getMetadataTy(LLVMContext &C)
Definition: Type.cpp:166
unsigned index_end() const
Definition: Attributes.h:633
This defines the Use class.
void reserve(size_type N)
Definition: SmallVector.h:377
static void predictValueUseListOrderImpl(const Value *V, const Function *F, unsigned ID, const OrderMap &OM, UseListOrderStack &Stack)
op_iterator op_end() const
Definition: Metadata.h:1061
unsigned getMetadataID(const Metadata *MD) const
void incorporateFunction(const Function &F)
incorporateFunction/purgeFunction - If you&#39;d like to deal with a function, use these two methods to g...
static bool isIntOrIntVectorValue(const std::pair< const Value *, unsigned > &V)
std::pair< iterator, bool > insert(const std::pair< KeyT, ValueT > &KV)
Definition: DenseMap.h:191
A tuple of MDNodes.
Definition: Metadata.h:1323
Class to represent struct types.
Definition: DerivedTypes.h:201
A Use represents the edge between a Value definition and its users.
Definition: Use.h:56
const TypeList & getTypes() const
This file contains the simple types necessary to represent the attributes associated with functions a...
TypeID
Definitions of all of the base types for the Type system.
Definition: Type.h:55
uint64_t computeBitsRequiredForTypeIndicies() const
unsigned getNumOperands() const
Definition: Metadata.cpp:1077
static const uint16_t * lookup(unsigned opcode, unsigned domain, ArrayRef< uint16_t[3]> Table)
op_iterator op_begin() const
Definition: Metadata.h:1057
unsigned idFor(const T &Entry) const
idFor - return the ID for an existing entry.
Definition: UniqueVector.h:58
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:245
reverse_iterator rend()
Definition: Module.h:583
op_range operands() const
Definition: Metadata.h:1065
iterator find(const KeyT &Val)
Definition: ValueMap.h:162
iterator end()
Get an iterator to the end of the symbol table.
Debug location.
iterator find(const_arg_type_t< KeyT > Val)
Definition: DenseMap.h:146
AttributeSet getAttributes(unsigned Index) const
The attributes for the specified index are returned.
User::op_iterator op_end()
bool isVoidTy() const
Return true if this is &#39;void&#39;.
Definition: Type.h:141
bool erase(const KeyT &Val)
Definition: DenseMap.h:268
unsigned getNumOperands() const
bool hasName() const
Definition: Value.h:251
LLVM Basic Block Representation.
Definition: BasicBlock.h:59
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
This is an important base class in LLVM.
Definition: Constant.h:42
void print(raw_ostream &OS, const ValueMapType &Map, const char *Name) const
LLVM_ATTRIBUTE_ALWAYS_INLINE iterator begin()
Definition: SmallVector.h:117
unsigned getInstructionID(const Instruction *I) const
std::vector< UseListOrder > UseListOrderStack
Definition: UseListOrder.h:40
User::op_iterator op_begin()
ValueEnumerator(const Module &M, bool ShouldPreserveUseListOrder)
iterator_range< named_metadata_iterator > named_metadata()
Definition: Module.h:702
unsigned getGlobalBasicBlockID(const BasicBlock *BB) const
getGlobalBasicBlockID - This returns the function-specific ID for the specified basic block...
void print(raw_ostream &O, bool IsForDebug=false) const
Implement operator<< on Value.
Definition: AsmWriter.cpp:4066
static OrderMap orderModule(const Module &M)
op_range operands()
Definition: User.h:238
static UseListOrderStack predictUseListOrder(const Module &M)
auto find_if(R &&Range, UnaryPredicate P) -> decltype(adl_begin(Range))
Provide wrappers to std::find_if which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:936
Metadata wrapper in the Value hierarchy.
Definition: Metadata.h:172
const AMDGPUAS & AS
Value * getValue() const
Definition: Metadata.h:377
unsigned first
void sort(IteratorTy Start, IteratorTy End)
Definition: STLExtras.h:859
reverse_iterator rbegin()
Definition: Module.h:581
iterator end()
Definition: ValueMap.h:142
void print(raw_ostream &OS, const Module *M=nullptr, bool IsForDebug=false) const
Print.
Definition: AsmWriter.cpp:4195
See the file comment.
Definition: ValueMap.h:86
auto size(R &&Range, typename std::enable_if< std::is_same< typename std::iterator_traits< decltype(Range.begin())>::iterator_category, std::random_access_iterator_tag >::value, void >::type *=nullptr) -> decltype(std::distance(Range.begin(), Range.end()))
Get the size of a range.
Definition: STLExtras.h:1032
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:861
Module.h This file contains the declarations for the Module class.
const DataFlowGraph & G
Definition: RDFGraph.cpp:211
LLVM_NODISCARD T pop_back_val()
Definition: SmallVector.h:382
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:133
void swap(llvm::BitVector &LHS, llvm::BitVector &RHS)
Implement std::swap in terms of BitVector swap.
Definition: BitVector.h:924
unsigned getTypeID(Type *T) const
UseListOrderStack UseListOrders
use_iterator use_begin()
Definition: Value.h:338
unsigned getNumUses() const
This method computes the number of uses of this Value.
Definition: Value.cpp:170
LLVM_ATTRIBUTE_ALWAYS_INLINE iterator end()
Definition: SmallVector.h:121
static void orderValue(const Value *V, OrderMap &OM)
unsigned insert(const T &Entry)
insert - Append entry to the vector if it doesn&#39;t already exist.
Definition: UniqueVector.h:41
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:62
iterator begin()
Definition: DenseMap.h:70
StringRef getName() const
Return a constant reference to the value&#39;s name.
Definition: Value.cpp:224
const Function * getParent() const
Return the enclosing method, or null if none.
Definition: BasicBlock.h:108
const NodeList & List
Definition: RDFGraph.cpp:210
#define I(x, y, z)
Definition: MD5.cpp:58
#define N
iterator end()
Definition: DenseMap.h:79
LLVM_NODISCARD std::enable_if<!is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type >::type dyn_cast(const Y &Val)
Definition: Casting.h:323
iterator_range< ifunc_iterator > ifuncs()
Definition: Module.h:624
ValueT lookup(const_arg_type_t< KeyT > Val) const
lookup - Return the entry for the specified key, or a default constructed value if no such entry exis...
Definition: DenseMap.h:181
static void IncorporateFunctionInfoGlobalBBIDs(const Function *F, DenseMap< const BasicBlock *, unsigned > &IDMap)
bool isDeclaration() const
Return true if the primary definition of this global value is outside of the current translation unit...
Definition: Globals.cpp:201
size_type count(const KeyT &Val) const
Return 1 if the specified key is in the map, 0 otherwise.
Definition: ValueMap.h:158
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
bool hasAttributes() const
Return true if attributes exists in this set.
Definition: Attributes.h:261
LLVM Value Representation.
Definition: Value.h:73
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:46
Invoke instruction.
iterator_range< global_iterator > globals()
Definition: Module.h:566
unsigned getComdatID(const Comdat *C) const
bool isEmpty() const
Return true if there are no attributes.
Definition: Attributes.h:645
Root of the metadata hierarchy.
Definition: Metadata.h:58
bool use_empty() const
Definition: Value.h:322
iterator_range< arg_iterator > args()
Definition: Function.h:675
unsigned index_begin() const
Use these to iterate over the valid attribute indices.
Definition: Attributes.h:632
bool erase(const KeyT &Val)
Definition: ValueMap.h:197
iterator_range< alias_iterator > aliases()
Definition: Module.h:606