LLVM  6.0.0svn
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/IR/Argument.h"
18 #include "llvm/IR/Attributes.h"
19 #include "llvm/IR/BasicBlock.h"
20 #include "llvm/IR/Constant.h"
22 #include "llvm/IR/DerivedTypes.h"
23 #include "llvm/IR/Function.h"
24 #include "llvm/IR/GlobalAlias.h"
25 #include "llvm/IR/GlobalIFunc.h"
26 #include "llvm/IR/GlobalObject.h"
27 #include "llvm/IR/GlobalValue.h"
28 #include "llvm/IR/GlobalVariable.h"
29 #include "llvm/IR/Instruction.h"
30 #include "llvm/IR/Instructions.h"
31 #include "llvm/IR/Metadata.h"
32 #include "llvm/IR/Module.h"
33 #include "llvm/IR/Type.h"
34 #include "llvm/IR/Use.h"
35 #include "llvm/IR/UseListOrder.h"
36 #include "llvm/IR/User.h"
37 #include "llvm/IR/Value.h"
39 #include "llvm/Support/Casting.h"
40 #include "llvm/Support/Compiler.h"
41 #include "llvm/Support/Debug.h"
44 #include <algorithm>
45 #include <cassert>
46 #include <cstddef>
47 #include <iterator>
48 #include <tuple>
49 #include <utility>
50 #include <vector>
51 
52 using namespace llvm;
53 
54 namespace {
55 
56 struct OrderMap {
58  unsigned LastGlobalConstantID = 0;
59  unsigned LastGlobalValueID = 0;
60 
61  OrderMap() = default;
62 
63  bool isGlobalConstant(unsigned ID) const {
64  return ID <= LastGlobalConstantID;
65  }
66 
67  bool isGlobalValue(unsigned ID) const {
68  return ID <= LastGlobalValueID && !isGlobalConstant(ID);
69  }
70 
71  unsigned size() const { return IDs.size(); }
72  std::pair<unsigned, bool> &operator[](const Value *V) { return IDs[V]; }
73 
74  std::pair<unsigned, bool> lookup(const Value *V) const {
75  return IDs.lookup(V);
76  }
77 
78  void index(const Value *V) {
79  // Explicitly sequence get-size and insert-value operations to avoid UB.
80  unsigned ID = IDs.size() + 1;
81  IDs[V].first = ID;
82  }
83 };
84 
85 } // end anonymous namespace
86 
87 static void orderValue(const Value *V, OrderMap &OM) {
88  if (OM.lookup(V).first)
89  return;
90 
91  if (const Constant *C = dyn_cast<Constant>(V))
92  if (C->getNumOperands() && !isa<GlobalValue>(C))
93  for (const Value *Op : C->operands())
94  if (!isa<BasicBlock>(Op) && !isa<GlobalValue>(Op))
95  orderValue(Op, OM);
96 
97  // Note: we cannot cache this lookup above, since inserting into the map
98  // changes the map's size, and thus affects the other IDs.
99  OM.index(V);
100 }
101 
102 static OrderMap orderModule(const Module &M) {
103  // This needs to match the order used by ValueEnumerator::ValueEnumerator()
104  // and ValueEnumerator::incorporateFunction().
105  OrderMap OM;
106 
107  // In the reader, initializers of GlobalValues are set *after* all the
108  // globals have been read. Rather than awkwardly modeling this behaviour
109  // directly in predictValueUseListOrderImpl(), just assign IDs to
110  // initializers of GlobalValues before GlobalValues themselves to model this
111  // implicitly.
112  for (const GlobalVariable &G : M.globals())
113  if (G.hasInitializer())
114  if (!isa<GlobalValue>(G.getInitializer()))
115  orderValue(G.getInitializer(), OM);
116  for (const GlobalAlias &A : M.aliases())
117  if (!isa<GlobalValue>(A.getAliasee()))
118  orderValue(A.getAliasee(), OM);
119  for (const GlobalIFunc &I : M.ifuncs())
120  if (!isa<GlobalValue>(I.getResolver()))
121  orderValue(I.getResolver(), OM);
122  for (const Function &F : M) {
123  for (const Use &U : F.operands())
124  if (!isa<GlobalValue>(U.get()))
125  orderValue(U.get(), OM);
126  }
127  OM.LastGlobalConstantID = OM.size();
128 
129  // Initializers of GlobalValues are processed in
130  // BitcodeReader::ResolveGlobalAndAliasInits(). Match the order there rather
131  // than ValueEnumerator, and match the code in predictValueUseListOrderImpl()
132  // by giving IDs in reverse order.
133  //
134  // Since GlobalValues never reference each other directly (just through
135  // initializers), their relative IDs only matter for determining order of
136  // uses in their initializers.
137  for (const Function &F : M)
138  orderValue(&F, OM);
139  for (const GlobalAlias &A : M.aliases())
140  orderValue(&A, OM);
141  for (const GlobalIFunc &I : M.ifuncs())
142  orderValue(&I, OM);
143  for (const GlobalVariable &G : M.globals())
144  orderValue(&G, OM);
145  OM.LastGlobalValueID = OM.size();
146 
147  for (const Function &F : M) {
148  if (F.isDeclaration())
149  continue;
150  // Here we need to match the union of ValueEnumerator::incorporateFunction()
151  // and WriteFunction(). Basic blocks are implicitly declared before
152  // anything else (by declaring their size).
153  for (const BasicBlock &BB : F)
154  orderValue(&BB, OM);
155  for (const Argument &A : F.args())
156  orderValue(&A, OM);
157  for (const BasicBlock &BB : F)
158  for (const Instruction &I : BB)
159  for (const Value *Op : I.operands())
160  if ((isa<Constant>(*Op) && !isa<GlobalValue>(*Op)) ||
161  isa<InlineAsm>(*Op))
162  orderValue(Op, OM);
163  for (const BasicBlock &BB : F)
164  for (const Instruction &I : BB)
165  orderValue(&I, OM);
166  }
167  return OM;
168 }
169 
170 static void predictValueUseListOrderImpl(const Value *V, const Function *F,
171  unsigned ID, const OrderMap &OM,
172  UseListOrderStack &Stack) {
173  // Predict use-list order for this one.
174  using Entry = std::pair<const Use *, unsigned>;
176  for (const Use &U : V->uses())
177  // Check if this user will be serialized.
178  if (OM.lookup(U.getUser()).first)
179  List.push_back(std::make_pair(&U, List.size()));
180 
181  if (List.size() < 2)
182  // We may have lost some users.
183  return;
184 
185  bool IsGlobalValue = OM.isGlobalValue(ID);
186  std::sort(List.begin(), List.end(), [&](const Entry &L, const Entry &R) {
187  const Use *LU = L.first;
188  const Use *RU = R.first;
189  if (LU == RU)
190  return false;
191 
192  auto LID = OM.lookup(LU->getUser()).first;
193  auto RID = OM.lookup(RU->getUser()).first;
194 
195  // Global values are processed in reverse order.
196  //
197  // Moreover, initializers of GlobalValues are set *after* all the globals
198  // have been read (despite having earlier IDs). Rather than awkwardly
199  // modeling this behaviour here, orderModule() has assigned IDs to
200  // initializers of GlobalValues before GlobalValues themselves.
201  if (OM.isGlobalValue(LID) && OM.isGlobalValue(RID))
202  return LID < RID;
203 
204  // If ID is 4, then expect: 7 6 5 1 2 3.
205  if (LID < RID) {
206  if (RID <= ID)
207  if (!IsGlobalValue) // GlobalValue uses don't get reversed.
208  return true;
209  return false;
210  }
211  if (RID < LID) {
212  if (LID <= ID)
213  if (!IsGlobalValue) // GlobalValue uses don't get reversed.
214  return false;
215  return true;
216  }
217 
218  // LID and RID are equal, so we have different operands of the same user.
219  // Assume operands are added in order for all instructions.
220  if (LID <= ID)
221  if (!IsGlobalValue) // GlobalValue uses don't get reversed.
222  return LU->getOperandNo() < RU->getOperandNo();
223  return LU->getOperandNo() > RU->getOperandNo();
224  });
225 
226  if (std::is_sorted(
227  List.begin(), List.end(),
228  [](const Entry &L, const Entry &R) { return L.second < R.second; }))
229  // Order is already correct.
230  return;
231 
232  // Store the shuffle.
233  Stack.emplace_back(V, F, List.size());
234  assert(List.size() == Stack.back().Shuffle.size() && "Wrong size");
235  for (size_t I = 0, E = List.size(); I != E; ++I)
236  Stack.back().Shuffle[I] = List[I].second;
237 }
238 
239 static void predictValueUseListOrder(const Value *V, const Function *F,
240  OrderMap &OM, UseListOrderStack &Stack) {
241  auto &IDPair = OM[V];
242  assert(IDPair.first && "Unmapped value");
243  if (IDPair.second)
244  // Already predicted.
245  return;
246 
247  // Do the actual prediction.
248  IDPair.second = true;
249  if (!V->use_empty() && std::next(V->use_begin()) != V->use_end())
250  predictValueUseListOrderImpl(V, F, IDPair.first, OM, Stack);
251 
252  // Recursive descent into constants.
253  if (const Constant *C = dyn_cast<Constant>(V))
254  if (C->getNumOperands()) // Visit GlobalValues.
255  for (const Value *Op : C->operands())
256  if (isa<Constant>(Op)) // Visit GlobalValues.
257  predictValueUseListOrder(Op, F, OM, Stack);
258 }
259 
261  OrderMap OM = orderModule(M);
262 
263  // Use-list orders need to be serialized after all the users have been added
264  // to a value, or else the shuffles will be incomplete. Store them per
265  // function in a stack.
266  //
267  // Aside from function order, the order of values doesn't matter much here.
268  UseListOrderStack Stack;
269 
270  // We want to visit the functions backward now so we can list function-local
271  // constants in the last Function they're used in. Module-level constants
272  // have already been visited above.
273  for (auto I = M.rbegin(), E = M.rend(); I != E; ++I) {
274  const Function &F = *I;
275  if (F.isDeclaration())
276  continue;
277  for (const BasicBlock &BB : F)
278  predictValueUseListOrder(&BB, &F, OM, Stack);
279  for (const Argument &A : F.args())
280  predictValueUseListOrder(&A, &F, OM, Stack);
281  for (const BasicBlock &BB : F)
282  for (const Instruction &I : BB)
283  for (const Value *Op : I.operands())
284  if (isa<Constant>(*Op) || isa<InlineAsm>(*Op)) // Visit GlobalValues.
285  predictValueUseListOrder(Op, &F, OM, Stack);
286  for (const BasicBlock &BB : F)
287  for (const Instruction &I : BB)
288  predictValueUseListOrder(&I, &F, OM, Stack);
289  }
290 
291  // Visit globals last, since the module-level use-list block will be seen
292  // before the function bodies are processed.
293  for (const GlobalVariable &G : M.globals())
294  predictValueUseListOrder(&G, nullptr, OM, Stack);
295  for (const Function &F : M)
296  predictValueUseListOrder(&F, nullptr, OM, Stack);
297  for (const GlobalAlias &A : M.aliases())
298  predictValueUseListOrder(&A, nullptr, OM, Stack);
299  for (const GlobalIFunc &I : M.ifuncs())
300  predictValueUseListOrder(&I, nullptr, OM, Stack);
301  for (const GlobalVariable &G : M.globals())
302  if (G.hasInitializer())
303  predictValueUseListOrder(G.getInitializer(), nullptr, OM, Stack);
304  for (const GlobalAlias &A : M.aliases())
305  predictValueUseListOrder(A.getAliasee(), nullptr, OM, Stack);
306  for (const GlobalIFunc &I : M.ifuncs())
307  predictValueUseListOrder(I.getResolver(), nullptr, OM, Stack);
308  for (const Function &F : M) {
309  for (const Use &U : F.operands())
310  predictValueUseListOrder(U.get(), nullptr, OM, Stack);
311  }
312 
313  return Stack;
314 }
315 
316 static bool isIntOrIntVectorValue(const std::pair<const Value*, unsigned> &V) {
317  return V.first->getType()->isIntOrIntVectorTy();
318 }
319 
321  bool ShouldPreserveUseListOrder)
322  : ShouldPreserveUseListOrder(ShouldPreserveUseListOrder) {
323  if (ShouldPreserveUseListOrder)
325 
326  // Enumerate the global variables.
327  for (const GlobalVariable &GV : M.globals())
328  EnumerateValue(&GV);
329 
330  // Enumerate the functions.
331  for (const Function & F : M) {
332  EnumerateValue(&F);
333  EnumerateAttributes(F.getAttributes());
334  }
335 
336  // Enumerate the aliases.
337  for (const GlobalAlias &GA : M.aliases())
338  EnumerateValue(&GA);
339 
340  // Enumerate the ifuncs.
341  for (const GlobalIFunc &GIF : M.ifuncs())
342  EnumerateValue(&GIF);
343 
344  // Remember what is the cutoff between globalvalue's and other constants.
345  unsigned FirstConstant = Values.size();
346 
347  // Enumerate the global variable initializers and attributes.
348  for (const GlobalVariable &GV : M.globals()) {
349  if (GV.hasInitializer())
350  EnumerateValue(GV.getInitializer());
351  if (GV.hasAttributes())
352  EnumerateAttributes(GV.getAttributesAsList(AttributeList::FunctionIndex));
353  }
354 
355  // Enumerate the aliasees.
356  for (const GlobalAlias &GA : M.aliases())
357  EnumerateValue(GA.getAliasee());
358 
359  // Enumerate the ifunc resolvers.
360  for (const GlobalIFunc &GIF : M.ifuncs())
361  EnumerateValue(GIF.getResolver());
362 
363  // Enumerate any optional Function data.
364  for (const Function &F : M)
365  for (const Use &U : F.operands())
366  EnumerateValue(U.get());
367 
368  // Enumerate the metadata type.
369  //
370  // TODO: Move this to ValueEnumerator::EnumerateOperandType() once bitcode
371  // only encodes the metadata type when it's used as a value.
372  EnumerateType(Type::getMetadataTy(M.getContext()));
373 
374  // Insert constants and metadata that are named at module level into the slot
375  // pool so that the module symbol table can refer to them...
376  EnumerateValueSymbolTable(M.getValueSymbolTable());
377  EnumerateNamedMetadata(M);
378 
380  for (const GlobalVariable &GV : M.globals()) {
381  MDs.clear();
382  GV.getAllMetadata(MDs);
383  for (const auto &I : MDs)
384  // FIXME: Pass GV to EnumerateMetadata and arrange for the bitcode writer
385  // to write metadata to the global variable's own metadata block
386  // (PR28134).
387  EnumerateMetadata(nullptr, I.second);
388  }
389 
390  // Enumerate types used by function bodies and argument lists.
391  for (const Function &F : M) {
392  for (const Argument &A : F.args())
393  EnumerateType(A.getType());
394 
395  // Enumerate metadata attached to this function.
396  MDs.clear();
397  F.getAllMetadata(MDs);
398  for (const auto &I : MDs)
399  EnumerateMetadata(F.isDeclaration() ? nullptr : &F, I.second);
400 
401  for (const BasicBlock &BB : F)
402  for (const Instruction &I : BB) {
403  for (const Use &Op : I.operands()) {
404  auto *MD = dyn_cast<MetadataAsValue>(&Op);
405  if (!MD) {
406  EnumerateOperandType(Op);
407  continue;
408  }
409 
410  // Local metadata is enumerated during function-incorporation.
411  if (isa<LocalAsMetadata>(MD->getMetadata()))
412  continue;
413 
414  EnumerateMetadata(&F, MD->getMetadata());
415  }
416  EnumerateType(I.getType());
417  if (const CallInst *CI = dyn_cast<CallInst>(&I))
418  EnumerateAttributes(CI->getAttributes());
419  else if (const InvokeInst *II = dyn_cast<InvokeInst>(&I))
420  EnumerateAttributes(II->getAttributes());
421 
422  // Enumerate metadata attached with this instruction.
423  MDs.clear();
424  I.getAllMetadataOtherThanDebugLoc(MDs);
425  for (unsigned i = 0, e = MDs.size(); i != e; ++i)
426  EnumerateMetadata(&F, MDs[i].second);
427 
428  // Don't enumerate the location directly -- it has a special record
429  // type -- but enumerate its operands.
430  if (DILocation *L = I.getDebugLoc())
431  for (const Metadata *Op : L->operands())
432  EnumerateMetadata(&F, Op);
433  }
434  }
435 
436  // Optimize constant ordering.
437  OptimizeConstants(FirstConstant, Values.size());
438 
439  // Organize metadata ordering.
440  organizeMetadata();
441 }
442 
443 unsigned ValueEnumerator::getInstructionID(const Instruction *Inst) const {
444  InstructionMapType::const_iterator I = InstructionMap.find(Inst);
445  assert(I != InstructionMap.end() && "Instruction is not mapped!");
446  return I->second;
447 }
448 
449 unsigned ValueEnumerator::getComdatID(const Comdat *C) const {
450  unsigned ComdatID = Comdats.idFor(C);
451  assert(ComdatID && "Comdat not found!");
452  return ComdatID;
453 }
454 
456  InstructionMap[I] = InstructionCount++;
457 }
458 
459 unsigned ValueEnumerator::getValueID(const Value *V) const {
460  if (auto *MD = dyn_cast<MetadataAsValue>(V))
461  return getMetadataID(MD->getMetadata());
462 
464  assert(I != ValueMap.end() && "Value not in slotcalculator!");
465  return I->second-1;
466 }
467 
468 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
470  print(dbgs(), ValueMap, "Default");
471  dbgs() << '\n';
472  print(dbgs(), MetadataMap, "MetaData");
473  dbgs() << '\n';
474 }
475 #endif
476 
478  const char *Name) const {
479  OS << "Map Name: " << Name << "\n";
480  OS << "Size: " << Map.size() << "\n";
481  for (ValueMapType::const_iterator I = Map.begin(),
482  E = Map.end(); I != E; ++I) {
483  const Value *V = I->first;
484  if (V->hasName())
485  OS << "Value: " << V->getName();
486  else
487  OS << "Value: [null]\n";
488  V->print(errs());
489  errs() << '\n';
490 
491  OS << " Uses(" << std::distance(V->use_begin(),V->use_end()) << "):";
492  for (const Use &U : V->uses()) {
493  if (&U != &*V->use_begin())
494  OS << ",";
495  if(U->hasName())
496  OS << " " << U->getName();
497  else
498  OS << " [null]";
499 
500  }
501  OS << "\n\n";
502  }
503 }
504 
506  const char *Name) const {
507  OS << "Map Name: " << Name << "\n";
508  OS << "Size: " << Map.size() << "\n";
509  for (auto I = Map.begin(), E = Map.end(); I != E; ++I) {
510  const Metadata *MD = I->first;
511  OS << "Metadata: slot = " << I->second.ID << "\n";
512  OS << "Metadata: function = " << I->second.F << "\n";
513  MD->print(OS);
514  OS << "\n";
515  }
516 }
517 
518 /// OptimizeConstants - Reorder constant pool for denser encoding.
519 void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) {
520  if (CstStart == CstEnd || CstStart+1 == CstEnd) return;
521 
522  if (ShouldPreserveUseListOrder)
523  // Optimizing constants makes the use-list order difficult to predict.
524  // Disable it for now when trying to preserve the order.
525  return;
526 
527  std::stable_sort(Values.begin() + CstStart, Values.begin() + CstEnd,
528  [this](const std::pair<const Value *, unsigned> &LHS,
529  const std::pair<const Value *, unsigned> &RHS) {
530  // Sort by plane.
531  if (LHS.first->getType() != RHS.first->getType())
532  return getTypeID(LHS.first->getType()) < getTypeID(RHS.first->getType());
533  // Then by frequency.
534  return LHS.second > RHS.second;
535  });
536 
537  // Ensure that integer and vector of integer constants are at the start of the
538  // constant pool. This is important so that GEP structure indices come before
539  // gep constant exprs.
540  std::stable_partition(Values.begin() + CstStart, Values.begin() + CstEnd,
542 
543  // Rebuild the modified portion of ValueMap.
544  for (; CstStart != CstEnd; ++CstStart)
545  ValueMap[Values[CstStart].first] = CstStart+1;
546 }
547 
548 /// EnumerateValueSymbolTable - Insert all of the values in the specified symbol
549 /// table into the values table.
550 void ValueEnumerator::EnumerateValueSymbolTable(const ValueSymbolTable &VST) {
551  for (ValueSymbolTable::const_iterator VI = VST.begin(), VE = VST.end();
552  VI != VE; ++VI)
553  EnumerateValue(VI->getValue());
554 }
555 
556 /// Insert all of the values referenced by named metadata in the specified
557 /// module.
558 void ValueEnumerator::EnumerateNamedMetadata(const Module &M) {
559  for (const auto &I : M.named_metadata())
560  EnumerateNamedMDNode(&I);
561 }
562 
563 void ValueEnumerator::EnumerateNamedMDNode(const NamedMDNode *MD) {
564  for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i)
565  EnumerateMetadata(nullptr, MD->getOperand(i));
566 }
567 
568 unsigned ValueEnumerator::getMetadataFunctionID(const Function *F) const {
569  return F ? getValueID(F) + 1 : 0;
570 }
571 
572 void ValueEnumerator::EnumerateMetadata(const Function *F, const Metadata *MD) {
573  EnumerateMetadata(getMetadataFunctionID(F), MD);
574 }
575 
576 void ValueEnumerator::EnumerateFunctionLocalMetadata(
577  const Function &F, const LocalAsMetadata *Local) {
578  EnumerateFunctionLocalMetadata(getMetadataFunctionID(&F), Local);
579 }
580 
581 void ValueEnumerator::dropFunctionFromMetadata(
582  MetadataMapType::value_type &FirstMD) {
584  auto push = [&Worklist](MetadataMapType::value_type &MD) {
585  auto &Entry = MD.second;
586 
587  // Nothing to do if this metadata isn't tagged.
588  if (!Entry.F)
589  return;
590 
591  // Drop the function tag.
592  Entry.F = 0;
593 
594  // If this is has an ID and is an MDNode, then its operands have entries as
595  // well. We need to drop the function from them too.
596  if (Entry.ID)
597  if (auto *N = dyn_cast<MDNode>(MD.first))
598  Worklist.push_back(N);
599  };
600  push(FirstMD);
601  while (!Worklist.empty())
602  for (const Metadata *Op : Worklist.pop_back_val()->operands()) {
603  if (!Op)
604  continue;
605  auto MD = MetadataMap.find(Op);
606  if (MD != MetadataMap.end())
607  push(*MD);
608  }
609 }
610 
611 void ValueEnumerator::EnumerateMetadata(unsigned F, const Metadata *MD) {
612  // It's vital for reader efficiency that uniqued subgraphs are done in
613  // post-order; it's expensive when their operands have forward references.
614  // If a distinct node is referenced from a uniqued node, it'll be delayed
615  // until the uniqued subgraph has been completely traversed.
616  SmallVector<const MDNode *, 32> DelayedDistinctNodes;
617 
618  // Start by enumerating MD, and then work through its transitive operands in
619  // post-order. This requires a depth-first search.
621  if (const MDNode *N = enumerateMetadataImpl(F, MD))
622  Worklist.push_back(std::make_pair(N, N->op_begin()));
623 
624  while (!Worklist.empty()) {
625  const MDNode *N = Worklist.back().first;
626 
627  // Enumerate operands until we hit a new node. We need to traverse these
628  // nodes' operands before visiting the rest of N's operands.
630  Worklist.back().second, N->op_end(),
631  [&](const Metadata *MD) { return enumerateMetadataImpl(F, MD); });
632  if (I != N->op_end()) {
633  auto *Op = cast<MDNode>(*I);
634  Worklist.back().second = ++I;
635 
636  // Delay traversing Op if it's a distinct node and N is uniqued.
637  if (Op->isDistinct() && !N->isDistinct())
638  DelayedDistinctNodes.push_back(Op);
639  else
640  Worklist.push_back(std::make_pair(Op, Op->op_begin()));
641  continue;
642  }
643 
644  // All the operands have been visited. Now assign an ID.
645  Worklist.pop_back();
646  MDs.push_back(N);
647  MetadataMap[N].ID = MDs.size();
648 
649  // Flush out any delayed distinct nodes; these are all the distinct nodes
650  // that are leaves in last uniqued subgraph.
651  if (Worklist.empty() || Worklist.back().first->isDistinct()) {
652  for (const MDNode *N : DelayedDistinctNodes)
653  Worklist.push_back(std::make_pair(N, N->op_begin()));
654  DelayedDistinctNodes.clear();
655  }
656  }
657 }
658 
659 const MDNode *ValueEnumerator::enumerateMetadataImpl(unsigned F, const Metadata *MD) {
660  if (!MD)
661  return nullptr;
662 
663  assert(
664  (isa<MDNode>(MD) || isa<MDString>(MD) || isa<ConstantAsMetadata>(MD)) &&
665  "Invalid metadata kind");
666 
667  auto Insertion = MetadataMap.insert(std::make_pair(MD, MDIndex(F)));
668  MDIndex &Entry = Insertion.first->second;
669  if (!Insertion.second) {
670  // Already mapped. If F doesn't match the function tag, drop it.
671  if (Entry.hasDifferentFunction(F))
672  dropFunctionFromMetadata(*Insertion.first);
673  return nullptr;
674  }
675 
676  // Don't assign IDs to metadata nodes.
677  if (auto *N = dyn_cast<MDNode>(MD))
678  return N;
679 
680  // Save the metadata.
681  MDs.push_back(MD);
682  Entry.ID = MDs.size();
683 
684  // Enumerate the constant, if any.
685  if (auto *C = dyn_cast<ConstantAsMetadata>(MD))
686  EnumerateValue(C->getValue());
687 
688  return nullptr;
689 }
690 
691 /// EnumerateFunctionLocalMetadataa - Incorporate function-local metadata
692 /// information reachable from the metadata.
693 void ValueEnumerator::EnumerateFunctionLocalMetadata(
694  unsigned F, const LocalAsMetadata *Local) {
695  assert(F && "Expected a function");
696 
697  // Check to see if it's already in!
698  MDIndex &Index = MetadataMap[Local];
699  if (Index.ID) {
700  assert(Index.F == F && "Expected the same function");
701  return;
702  }
703 
704  MDs.push_back(Local);
705  Index.F = F;
706  Index.ID = MDs.size();
707 
708  EnumerateValue(Local->getValue());
709 }
710 
711 static unsigned getMetadataTypeOrder(const Metadata *MD) {
712  // Strings are emitted in bulk and must come first.
713  if (isa<MDString>(MD))
714  return 0;
715 
716  // ConstantAsMetadata doesn't reference anything. We may as well shuffle it
717  // to the front since we can detect it.
718  auto *N = dyn_cast<MDNode>(MD);
719  if (!N)
720  return 1;
721 
722  // The reader is fast forward references for distinct node operands, but slow
723  // when uniqued operands are unresolved.
724  return N->isDistinct() ? 2 : 3;
725 }
726 
727 void ValueEnumerator::organizeMetadata() {
728  assert(MetadataMap.size() == MDs.size() &&
729  "Metadata map and vector out of sync");
730 
731  if (MDs.empty())
732  return;
733 
734  // Copy out the index information from MetadataMap in order to choose a new
735  // order.
737  Order.reserve(MetadataMap.size());
738  for (const Metadata *MD : MDs)
739  Order.push_back(MetadataMap.lookup(MD));
740 
741  // Partition:
742  // - by function, then
743  // - by isa<MDString>
744  // and then sort by the original/current ID. Since the IDs are guaranteed to
745  // be unique, the result of std::sort will be deterministic. There's no need
746  // for std::stable_sort.
747  std::sort(Order.begin(), Order.end(), [this](MDIndex LHS, MDIndex RHS) {
748  return std::make_tuple(LHS.F, getMetadataTypeOrder(LHS.get(MDs)), LHS.ID) <
749  std::make_tuple(RHS.F, getMetadataTypeOrder(RHS.get(MDs)), RHS.ID);
750  });
751 
752  // Rebuild MDs, index the metadata ranges for each function in FunctionMDs,
753  // and fix up MetadataMap.
754  std::vector<const Metadata *> OldMDs = std::move(MDs);
755  MDs.reserve(OldMDs.size());
756  for (unsigned I = 0, E = Order.size(); I != E && !Order[I].F; ++I) {
757  auto *MD = Order[I].get(OldMDs);
758  MDs.push_back(MD);
759  MetadataMap[MD].ID = I + 1;
760  if (isa<MDString>(MD))
761  ++NumMDStrings;
762  }
763 
764  // Return early if there's nothing for the functions.
765  if (MDs.size() == Order.size())
766  return;
767 
768  // Build the function metadata ranges.
769  MDRange R;
770  FunctionMDs.reserve(OldMDs.size());
771  unsigned PrevF = 0;
772  for (unsigned I = MDs.size(), E = Order.size(), ID = MDs.size(); I != E;
773  ++I) {
774  unsigned F = Order[I].F;
775  if (!PrevF) {
776  PrevF = F;
777  } else if (PrevF != F) {
778  R.Last = FunctionMDs.size();
779  std::swap(R, FunctionMDInfo[PrevF]);
780  R.First = FunctionMDs.size();
781 
782  ID = MDs.size();
783  PrevF = F;
784  }
785 
786  auto *MD = Order[I].get(OldMDs);
787  FunctionMDs.push_back(MD);
788  MetadataMap[MD].ID = ++ID;
789  if (isa<MDString>(MD))
790  ++R.NumStrings;
791  }
792  R.Last = FunctionMDs.size();
793  FunctionMDInfo[PrevF] = R;
794 }
795 
796 void ValueEnumerator::incorporateFunctionMetadata(const Function &F) {
797  NumModuleMDs = MDs.size();
798 
799  auto R = FunctionMDInfo.lookup(getValueID(&F) + 1);
800  NumMDStrings = R.NumStrings;
801  MDs.insert(MDs.end(), FunctionMDs.begin() + R.First,
802  FunctionMDs.begin() + R.Last);
803 }
804 
805 void ValueEnumerator::EnumerateValue(const Value *V) {
806  assert(!V->getType()->isVoidTy() && "Can't insert void values!");
807  assert(!isa<MetadataAsValue>(V) && "EnumerateValue doesn't handle Metadata!");
808 
809  // Check to see if it's already in!
810  unsigned &ValueID = ValueMap[V];
811  if (ValueID) {
812  // Increment use count.
813  Values[ValueID-1].second++;
814  return;
815  }
816 
817  if (auto *GO = dyn_cast<GlobalObject>(V))
818  if (const Comdat *C = GO->getComdat())
819  Comdats.insert(C);
820 
821  // Enumerate the type of this value.
822  EnumerateType(V->getType());
823 
824  if (const Constant *C = dyn_cast<Constant>(V)) {
825  if (isa<GlobalValue>(C)) {
826  // Initializers for globals are handled explicitly elsewhere.
827  } else if (C->getNumOperands()) {
828  // If a constant has operands, enumerate them. This makes sure that if a
829  // constant has uses (for example an array of const ints), that they are
830  // inserted also.
831 
832  // We prefer to enumerate them with values before we enumerate the user
833  // itself. This makes it more likely that we can avoid forward references
834  // in the reader. We know that there can be no cycles in the constants
835  // graph that don't go through a global variable.
836  for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
837  I != E; ++I)
838  if (!isa<BasicBlock>(*I)) // Don't enumerate BB operand to BlockAddress.
839  EnumerateValue(*I);
840 
841  // Finally, add the value. Doing this could make the ValueID reference be
842  // dangling, don't reuse it.
843  Values.push_back(std::make_pair(V, 1U));
844  ValueMap[V] = Values.size();
845  return;
846  }
847  }
848 
849  // Add the value.
850  Values.push_back(std::make_pair(V, 1U));
851  ValueID = Values.size();
852 }
853 
854 
855 void ValueEnumerator::EnumerateType(Type *Ty) {
856  unsigned *TypeID = &TypeMap[Ty];
857 
858  // We've already seen this type.
859  if (*TypeID)
860  return;
861 
862  // If it is a non-anonymous struct, mark the type as being visited so that we
863  // don't recursively visit it. This is safe because we allow forward
864  // references of these in the bitcode reader.
865  if (StructType *STy = dyn_cast<StructType>(Ty))
866  if (!STy->isLiteral())
867  *TypeID = ~0U;
868 
869  // Enumerate all of the subtypes before we enumerate this type. This ensures
870  // that the type will be enumerated in an order that can be directly built.
871  for (Type *SubTy : Ty->subtypes())
872  EnumerateType(SubTy);
873 
874  // Refresh the TypeID pointer in case the table rehashed.
875  TypeID = &TypeMap[Ty];
876 
877  // Check to see if we got the pointer another way. This can happen when
878  // enumerating recursive types that hit the base case deeper than they start.
879  //
880  // If this is actually a struct that we are treating as forward ref'able,
881  // then emit the definition now that all of its contents are available.
882  if (*TypeID && *TypeID != ~0U)
883  return;
884 
885  // Add this type now that its contents are all happily enumerated.
886  Types.push_back(Ty);
887 
888  *TypeID = Types.size();
889 }
890 
891 // Enumerate the types for the specified value. If the value is a constant,
892 // walk through it, enumerating the types of the constant.
893 void ValueEnumerator::EnumerateOperandType(const Value *V) {
894  EnumerateType(V->getType());
895 
896  assert(!isa<MetadataAsValue>(V) && "Unexpected metadata operand");
897 
898  const Constant *C = dyn_cast<Constant>(V);
899  if (!C)
900  return;
901 
902  // If this constant is already enumerated, ignore it, we know its type must
903  // be enumerated.
904  if (ValueMap.count(C))
905  return;
906 
907  // This constant may have operands, make sure to enumerate the types in
908  // them.
909  for (const Value *Op : C->operands()) {
910  // Don't enumerate basic blocks here, this happens as operands to
911  // blockaddress.
912  if (isa<BasicBlock>(Op))
913  continue;
914 
915  EnumerateOperandType(Op);
916  }
917 }
918 
919 void ValueEnumerator::EnumerateAttributes(AttributeList PAL) {
920  if (PAL.isEmpty()) return; // null is always 0.
921 
922  // Do a lookup.
923  unsigned &Entry = AttributeListMap[PAL];
924  if (Entry == 0) {
925  // Never saw this before, add it.
926  AttributeLists.push_back(PAL);
927  Entry = AttributeLists.size();
928  }
929 
930  // Do lookups for all attribute groups.
931  for (unsigned i = PAL.index_begin(), e = PAL.index_end(); i != e; ++i) {
932  AttributeSet AS = PAL.getAttributes(i);
933  if (!AS.hasAttributes())
934  continue;
935  IndexAndAttrSet Pair = {i, AS};
936  unsigned &Entry = AttributeGroupMap[Pair];
937  if (Entry == 0) {
938  AttributeGroups.push_back(Pair);
939  Entry = AttributeGroups.size();
940  }
941  }
942 }
943 
945  InstructionCount = 0;
946  NumModuleValues = Values.size();
947 
948  // Add global metadata to the function block. This doesn't include
949  // LocalAsMetadata.
950  incorporateFunctionMetadata(F);
951 
952  // Adding function arguments to the value table.
953  for (const auto &I : F.args())
954  EnumerateValue(&I);
955 
956  FirstFuncConstantID = Values.size();
957 
958  // Add all function-level constants to the value table.
959  for (const BasicBlock &BB : F) {
960  for (const Instruction &I : BB)
961  for (const Use &OI : I.operands()) {
962  if ((isa<Constant>(OI) && !isa<GlobalValue>(OI)) || isa<InlineAsm>(OI))
963  EnumerateValue(OI);
964  }
965  BasicBlocks.push_back(&BB);
966  ValueMap[&BB] = BasicBlocks.size();
967  }
968 
969  // Optimize the constant layout.
970  OptimizeConstants(FirstFuncConstantID, Values.size());
971 
972  // Add the function's parameter attributes so they are available for use in
973  // the function's instruction.
974  EnumerateAttributes(F.getAttributes());
975 
976  FirstInstID = Values.size();
977 
978  SmallVector<LocalAsMetadata *, 8> FnLocalMDVector;
979  // Add all of the instructions.
980  for (const BasicBlock &BB : F) {
981  for (const Instruction &I : BB) {
982  for (const Use &OI : I.operands()) {
983  if (auto *MD = dyn_cast<MetadataAsValue>(&OI))
984  if (auto *Local = dyn_cast<LocalAsMetadata>(MD->getMetadata()))
985  // Enumerate metadata after the instructions they might refer to.
986  FnLocalMDVector.push_back(Local);
987  }
988 
989  if (!I.getType()->isVoidTy())
990  EnumerateValue(&I);
991  }
992  }
993 
994  // Add all of the function-local metadata.
995  for (unsigned i = 0, e = FnLocalMDVector.size(); i != e; ++i) {
996  // At this point, every local values have been incorporated, we shouldn't
997  // have a metadata operand that references a value that hasn't been seen.
998  assert(ValueMap.count(FnLocalMDVector[i]->getValue()) &&
999  "Missing value for metadata operand");
1000  EnumerateFunctionLocalMetadata(F, FnLocalMDVector[i]);
1001  }
1002 }
1003 
1005  /// Remove purged values from the ValueMap.
1006  for (unsigned i = NumModuleValues, e = Values.size(); i != e; ++i)
1007  ValueMap.erase(Values[i].first);
1008  for (unsigned i = NumModuleMDs, e = MDs.size(); i != e; ++i)
1009  MetadataMap.erase(MDs[i]);
1010  for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i)
1011  ValueMap.erase(BasicBlocks[i]);
1012 
1013  Values.resize(NumModuleValues);
1014  MDs.resize(NumModuleMDs);
1015  BasicBlocks.clear();
1016  NumMDStrings = 0;
1017 }
1018 
1021  unsigned Counter = 0;
1022  for (const BasicBlock &BB : *F)
1023  IDMap[&BB] = ++Counter;
1024 }
1025 
1026 /// getGlobalBasicBlockID - This returns the function-specific ID for the
1027 /// specified basic block. This is relatively expensive information, so it
1028 /// should only be used by rare constructs such as address-of-label.
1030  unsigned &Idx = GlobalBasicBlockIDs[BB];
1031  if (Idx != 0)
1032  return Idx-1;
1033 
1034  IncorporateFunctionInfoGlobalBBIDs(BB->getParent(), GlobalBasicBlockIDs);
1035  return getGlobalBasicBlockID(BB);
1036 }
1037 
1039  return Log2_32_Ceil(getTypes().size() + 1);
1040 }
uint64_t CallInst * C
use_iterator use_end()
Definition: Value.h:348
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:544
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:314
iterator_range< use_iterator > uses()
Definition: Value.h:356
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:1073
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
#define LLVM_DUMP_METHOD
Mark debug helper function definitions like dump() that should not be stripped from debug builds...
Definition: Compiler.h:449
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:136
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)
static Type * getMetadataTy(LLVMContext &C)
Definition: Type.cpp:166
unsigned index_end() const
Definition: Attributes.h:634
This defines the Use class.
void reserve(size_type N)
Definition: SmallVector.h:380
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
op_iterator op_begin()
Definition: User.h:214
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:1069
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:578
op_range operands() const
Definition: Metadata.h:1065
iterator find(const KeyT &Val)
Definition: ValueMap.h:158
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.
bool isVoidTy() const
Return true if this is &#39;void&#39;.
Definition: Type.h:141
bool erase(const KeyT &Val)
Definition: DenseMap.h:268
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:116
unsigned getInstructionID(const Instruction *I) const
std::vector< UseListOrder > UseListOrderStack
Definition: UseListOrder.h:40
ValueEnumerator(const Module &M, bool ShouldPreserveUseListOrder)
iterator_range< named_metadata_iterator > named_metadata()
Definition: Module.h:697
op_iterator op_end()
Definition: User.h:216
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:3494
static OrderMap orderModule(const Module &M)
op_range operands()
Definition: User.h:222
static UseListOrderStack predictUseListOrder(const Module &M)
Metadata wrapper in the Value hierarchy.
Definition: Metadata.h:172
const AMDGPUAS & AS
Value * getValue() const
Definition: Metadata.h:377
unsigned first
reverse_iterator rbegin()
Definition: Module.h:576
iterator end()
Definition: ValueMap.h:138
void print(raw_ostream &OS, const Module *M=nullptr, bool IsForDebug=false) const
Print.
Definition: AsmWriter.cpp:3627
unsigned getNumOperands() const
Definition: User.h:176
See the file comment.
Definition: ValueMap.h:86
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:864
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:385
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:132
void swap(llvm::BitVector &LHS, llvm::BitVector &RHS)
Implement std::swap in terms of BitVector swap.
Definition: BitVector.h:923
unsigned getTypeID(Type *T) const
UseListOrderStack UseListOrders
use_iterator use_begin()
Definition: Value.h:340
LLVM_ATTRIBUTE_ALWAYS_INLINE iterator end()
Definition: SmallVector.h:120
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:61
iterator begin()
Definition: DenseMap.h:70
StringRef getName() const
Return a constant reference to the value&#39;s name.
Definition: Value.cpp:220
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:619
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:154
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:44
Invoke instruction.
iterator_range< global_iterator > globals()
Definition: Module.h:561
void sort(Policy policy, RandomAccessIterator Start, RandomAccessIterator End, const Comparator &Comp=Comparator())
Definition: Parallel.h:199
unsigned getComdatID(const Comdat *C) const
auto find_if(R &&Range, UnaryPredicate P) -> decltype(std::begin(Range))
Provide wrappers to std::find_if which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:795
bool isEmpty() const
Return true if there are no attributes.
Definition: Attributes.h:646
Root of the metadata hierarchy.
Definition: Metadata.h:58
bool use_empty() const
Definition: Value.h:328
iterator_range< arg_iterator > args()
Definition: Function.h:621
unsigned index_begin() const
Use these to iterate over the valid attribute indices.
Definition: Attributes.h:633
bool erase(const KeyT &Val)
Definition: ValueMap.h:193
iterator_range< alias_iterator > aliases()
Definition: Module.h:601