LLVM  10.0.0svn
ValueEnumerator.cpp
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1 //===- ValueEnumerator.cpp - Number values and types for bitcode writer ---===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the ValueEnumerator class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "ValueEnumerator.h"
14 #include "llvm/ADT/DenseMap.h"
15 #include "llvm/ADT/SmallVector.h"
16 #include "llvm/Config/llvm-config.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  llvm::sort(List, [&](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 auto *Call = dyn_cast<CallBase>(&I))
418  EnumerateAttributes(Call->getAttributes());
419 
420  // Enumerate metadata attached with this instruction.
421  MDs.clear();
422  I.getAllMetadataOtherThanDebugLoc(MDs);
423  for (unsigned i = 0, e = MDs.size(); i != e; ++i)
424  EnumerateMetadata(&F, MDs[i].second);
425 
426  // Don't enumerate the location directly -- it has a special record
427  // type -- but enumerate its operands.
428  if (DILocation *L = I.getDebugLoc())
429  for (const Metadata *Op : L->operands())
430  EnumerateMetadata(&F, Op);
431  }
432  }
433 
434  // Optimize constant ordering.
435  OptimizeConstants(FirstConstant, Values.size());
436 
437  // Organize metadata ordering.
438  organizeMetadata();
439 }
440 
441 unsigned ValueEnumerator::getInstructionID(const Instruction *Inst) const {
442  InstructionMapType::const_iterator I = InstructionMap.find(Inst);
443  assert(I != InstructionMap.end() && "Instruction is not mapped!");
444  return I->second;
445 }
446 
447 unsigned ValueEnumerator::getComdatID(const Comdat *C) const {
448  unsigned ComdatID = Comdats.idFor(C);
449  assert(ComdatID && "Comdat not found!");
450  return ComdatID;
451 }
452 
454  InstructionMap[I] = InstructionCount++;
455 }
456 
457 unsigned ValueEnumerator::getValueID(const Value *V) const {
458  if (auto *MD = dyn_cast<MetadataAsValue>(V))
459  return getMetadataID(MD->getMetadata());
460 
462  assert(I != ValueMap.end() && "Value not in slotcalculator!");
463  return I->second-1;
464 }
465 
466 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
468  print(dbgs(), ValueMap, "Default");
469  dbgs() << '\n';
470  print(dbgs(), MetadataMap, "MetaData");
471  dbgs() << '\n';
472 }
473 #endif
474 
476  const char *Name) const {
477  OS << "Map Name: " << Name << "\n";
478  OS << "Size: " << Map.size() << "\n";
479  for (ValueMapType::const_iterator I = Map.begin(),
480  E = Map.end(); I != E; ++I) {
481  const Value *V = I->first;
482  if (V->hasName())
483  OS << "Value: " << V->getName();
484  else
485  OS << "Value: [null]\n";
486  V->print(errs());
487  errs() << '\n';
488 
489  OS << " Uses(" << V->getNumUses() << "):";
490  for (const Use &U : V->uses()) {
491  if (&U != &*V->use_begin())
492  OS << ",";
493  if(U->hasName())
494  OS << " " << U->getName();
495  else
496  OS << " [null]";
497 
498  }
499  OS << "\n\n";
500  }
501 }
502 
504  const char *Name) const {
505  OS << "Map Name: " << Name << "\n";
506  OS << "Size: " << Map.size() << "\n";
507  for (auto I = Map.begin(), E = Map.end(); I != E; ++I) {
508  const Metadata *MD = I->first;
509  OS << "Metadata: slot = " << I->second.ID << "\n";
510  OS << "Metadata: function = " << I->second.F << "\n";
511  MD->print(OS);
512  OS << "\n";
513  }
514 }
515 
516 /// OptimizeConstants - Reorder constant pool for denser encoding.
517 void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) {
518  if (CstStart == CstEnd || CstStart+1 == CstEnd) return;
519 
520  if (ShouldPreserveUseListOrder)
521  // Optimizing constants makes the use-list order difficult to predict.
522  // Disable it for now when trying to preserve the order.
523  return;
524 
525  std::stable_sort(Values.begin() + CstStart, Values.begin() + CstEnd,
526  [this](const std::pair<const Value *, unsigned> &LHS,
527  const std::pair<const Value *, unsigned> &RHS) {
528  // Sort by plane.
529  if (LHS.first->getType() != RHS.first->getType())
530  return getTypeID(LHS.first->getType()) < getTypeID(RHS.first->getType());
531  // Then by frequency.
532  return LHS.second > RHS.second;
533  });
534 
535  // Ensure that integer and vector of integer constants are at the start of the
536  // constant pool. This is important so that GEP structure indices come before
537  // gep constant exprs.
538  std::stable_partition(Values.begin() + CstStart, Values.begin() + CstEnd,
540 
541  // Rebuild the modified portion of ValueMap.
542  for (; CstStart != CstEnd; ++CstStart)
543  ValueMap[Values[CstStart].first] = CstStart+1;
544 }
545 
546 /// EnumerateValueSymbolTable - Insert all of the values in the specified symbol
547 /// table into the values table.
548 void ValueEnumerator::EnumerateValueSymbolTable(const ValueSymbolTable &VST) {
549  for (ValueSymbolTable::const_iterator VI = VST.begin(), VE = VST.end();
550  VI != VE; ++VI)
551  EnumerateValue(VI->getValue());
552 }
553 
554 /// Insert all of the values referenced by named metadata in the specified
555 /// module.
556 void ValueEnumerator::EnumerateNamedMetadata(const Module &M) {
557  for (const auto &I : M.named_metadata())
558  EnumerateNamedMDNode(&I);
559 }
560 
561 void ValueEnumerator::EnumerateNamedMDNode(const NamedMDNode *MD) {
562  for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i)
563  EnumerateMetadata(nullptr, MD->getOperand(i));
564 }
565 
566 unsigned ValueEnumerator::getMetadataFunctionID(const Function *F) const {
567  return F ? getValueID(F) + 1 : 0;
568 }
569 
570 void ValueEnumerator::EnumerateMetadata(const Function *F, const Metadata *MD) {
571  EnumerateMetadata(getMetadataFunctionID(F), MD);
572 }
573 
574 void ValueEnumerator::EnumerateFunctionLocalMetadata(
575  const Function &F, const LocalAsMetadata *Local) {
576  EnumerateFunctionLocalMetadata(getMetadataFunctionID(&F), Local);
577 }
578 
579 void ValueEnumerator::dropFunctionFromMetadata(
580  MetadataMapType::value_type &FirstMD) {
582  auto push = [&Worklist](MetadataMapType::value_type &MD) {
583  auto &Entry = MD.second;
584 
585  // Nothing to do if this metadata isn't tagged.
586  if (!Entry.F)
587  return;
588 
589  // Drop the function tag.
590  Entry.F = 0;
591 
592  // If this is has an ID and is an MDNode, then its operands have entries as
593  // well. We need to drop the function from them too.
594  if (Entry.ID)
595  if (auto *N = dyn_cast<MDNode>(MD.first))
596  Worklist.push_back(N);
597  };
598  push(FirstMD);
599  while (!Worklist.empty())
600  for (const Metadata *Op : Worklist.pop_back_val()->operands()) {
601  if (!Op)
602  continue;
603  auto MD = MetadataMap.find(Op);
604  if (MD != MetadataMap.end())
605  push(*MD);
606  }
607 }
608 
609 void ValueEnumerator::EnumerateMetadata(unsigned F, const Metadata *MD) {
610  // It's vital for reader efficiency that uniqued subgraphs are done in
611  // post-order; it's expensive when their operands have forward references.
612  // If a distinct node is referenced from a uniqued node, it'll be delayed
613  // until the uniqued subgraph has been completely traversed.
614  SmallVector<const MDNode *, 32> DelayedDistinctNodes;
615 
616  // Start by enumerating MD, and then work through its transitive operands in
617  // post-order. This requires a depth-first search.
619  if (const MDNode *N = enumerateMetadataImpl(F, MD))
620  Worklist.push_back(std::make_pair(N, N->op_begin()));
621 
622  while (!Worklist.empty()) {
623  const MDNode *N = Worklist.back().first;
624 
625  // Enumerate operands until we hit a new node. We need to traverse these
626  // nodes' operands before visiting the rest of N's operands.
628  Worklist.back().second, N->op_end(),
629  [&](const Metadata *MD) { return enumerateMetadataImpl(F, MD); });
630  if (I != N->op_end()) {
631  auto *Op = cast<MDNode>(*I);
632  Worklist.back().second = ++I;
633 
634  // Delay traversing Op if it's a distinct node and N is uniqued.
635  if (Op->isDistinct() && !N->isDistinct())
636  DelayedDistinctNodes.push_back(Op);
637  else
638  Worklist.push_back(std::make_pair(Op, Op->op_begin()));
639  continue;
640  }
641 
642  // All the operands have been visited. Now assign an ID.
643  Worklist.pop_back();
644  MDs.push_back(N);
645  MetadataMap[N].ID = MDs.size();
646 
647  // Flush out any delayed distinct nodes; these are all the distinct nodes
648  // that are leaves in last uniqued subgraph.
649  if (Worklist.empty() || Worklist.back().first->isDistinct()) {
650  for (const MDNode *N : DelayedDistinctNodes)
651  Worklist.push_back(std::make_pair(N, N->op_begin()));
652  DelayedDistinctNodes.clear();
653  }
654  }
655 }
656 
657 const MDNode *ValueEnumerator::enumerateMetadataImpl(unsigned F, const Metadata *MD) {
658  if (!MD)
659  return nullptr;
660 
661  assert(
662  (isa<MDNode>(MD) || isa<MDString>(MD) || isa<ConstantAsMetadata>(MD)) &&
663  "Invalid metadata kind");
664 
665  auto Insertion = MetadataMap.insert(std::make_pair(MD, MDIndex(F)));
666  MDIndex &Entry = Insertion.first->second;
667  if (!Insertion.second) {
668  // Already mapped. If F doesn't match the function tag, drop it.
669  if (Entry.hasDifferentFunction(F))
670  dropFunctionFromMetadata(*Insertion.first);
671  return nullptr;
672  }
673 
674  // Don't assign IDs to metadata nodes.
675  if (auto *N = dyn_cast<MDNode>(MD))
676  return N;
677 
678  // Save the metadata.
679  MDs.push_back(MD);
680  Entry.ID = MDs.size();
681 
682  // Enumerate the constant, if any.
683  if (auto *C = dyn_cast<ConstantAsMetadata>(MD))
684  EnumerateValue(C->getValue());
685 
686  return nullptr;
687 }
688 
689 /// EnumerateFunctionLocalMetadataa - Incorporate function-local metadata
690 /// information reachable from the metadata.
691 void ValueEnumerator::EnumerateFunctionLocalMetadata(
692  unsigned F, const LocalAsMetadata *Local) {
693  assert(F && "Expected a function");
694 
695  // Check to see if it's already in!
696  MDIndex &Index = MetadataMap[Local];
697  if (Index.ID) {
698  assert(Index.F == F && "Expected the same function");
699  return;
700  }
701 
702  MDs.push_back(Local);
703  Index.F = F;
704  Index.ID = MDs.size();
705 
706  EnumerateValue(Local->getValue());
707 }
708 
709 static unsigned getMetadataTypeOrder(const Metadata *MD) {
710  // Strings are emitted in bulk and must come first.
711  if (isa<MDString>(MD))
712  return 0;
713 
714  // ConstantAsMetadata doesn't reference anything. We may as well shuffle it
715  // to the front since we can detect it.
716  auto *N = dyn_cast<MDNode>(MD);
717  if (!N)
718  return 1;
719 
720  // The reader is fast forward references for distinct node operands, but slow
721  // when uniqued operands are unresolved.
722  return N->isDistinct() ? 2 : 3;
723 }
724 
725 void ValueEnumerator::organizeMetadata() {
726  assert(MetadataMap.size() == MDs.size() &&
727  "Metadata map and vector out of sync");
728 
729  if (MDs.empty())
730  return;
731 
732  // Copy out the index information from MetadataMap in order to choose a new
733  // order.
735  Order.reserve(MetadataMap.size());
736  for (const Metadata *MD : MDs)
737  Order.push_back(MetadataMap.lookup(MD));
738 
739  // Partition:
740  // - by function, then
741  // - by isa<MDString>
742  // and then sort by the original/current ID. Since the IDs are guaranteed to
743  // be unique, the result of std::sort will be deterministic. There's no need
744  // for std::stable_sort.
745  llvm::sort(Order, [this](MDIndex LHS, MDIndex RHS) {
746  return std::make_tuple(LHS.F, getMetadataTypeOrder(LHS.get(MDs)), LHS.ID) <
747  std::make_tuple(RHS.F, getMetadataTypeOrder(RHS.get(MDs)), RHS.ID);
748  });
749 
750  // Rebuild MDs, index the metadata ranges for each function in FunctionMDs,
751  // and fix up MetadataMap.
752  std::vector<const Metadata *> OldMDs;
753  MDs.swap(OldMDs);
754  MDs.reserve(OldMDs.size());
755  for (unsigned I = 0, E = Order.size(); I != E && !Order[I].F; ++I) {
756  auto *MD = Order[I].get(OldMDs);
757  MDs.push_back(MD);
758  MetadataMap[MD].ID = I + 1;
759  if (isa<MDString>(MD))
760  ++NumMDStrings;
761  }
762 
763  // Return early if there's nothing for the functions.
764  if (MDs.size() == Order.size())
765  return;
766 
767  // Build the function metadata ranges.
768  MDRange R;
769  FunctionMDs.reserve(OldMDs.size());
770  unsigned PrevF = 0;
771  for (unsigned I = MDs.size(), E = Order.size(), ID = MDs.size(); I != E;
772  ++I) {
773  unsigned F = Order[I].F;
774  if (!PrevF) {
775  PrevF = F;
776  } else if (PrevF != F) {
777  R.Last = FunctionMDs.size();
778  std::swap(R, FunctionMDInfo[PrevF]);
779  R.First = FunctionMDs.size();
780 
781  ID = MDs.size();
782  PrevF = F;
783  }
784 
785  auto *MD = Order[I].get(OldMDs);
786  FunctionMDs.push_back(MD);
787  MetadataMap[MD].ID = ++ID;
788  if (isa<MDString>(MD))
789  ++R.NumStrings;
790  }
791  R.Last = FunctionMDs.size();
792  FunctionMDInfo[PrevF] = R;
793 }
794 
795 void ValueEnumerator::incorporateFunctionMetadata(const Function &F) {
796  NumModuleMDs = MDs.size();
797 
798  auto R = FunctionMDInfo.lookup(getValueID(&F) + 1);
799  NumMDStrings = R.NumStrings;
800  MDs.insert(MDs.end(), FunctionMDs.begin() + R.First,
801  FunctionMDs.begin() + R.Last);
802 }
803 
804 void ValueEnumerator::EnumerateValue(const Value *V) {
805  assert(!V->getType()->isVoidTy() && "Can't insert void values!");
806  assert(!isa<MetadataAsValue>(V) && "EnumerateValue doesn't handle Metadata!");
807 
808  // Check to see if it's already in!
809  unsigned &ValueID = ValueMap[V];
810  if (ValueID) {
811  // Increment use count.
812  Values[ValueID-1].second++;
813  return;
814  }
815 
816  if (auto *GO = dyn_cast<GlobalObject>(V))
817  if (const Comdat *C = GO->getComdat())
818  Comdats.insert(C);
819 
820  // Enumerate the type of this value.
821  EnumerateType(V->getType());
822 
823  if (const Constant *C = dyn_cast<Constant>(V)) {
824  if (isa<GlobalValue>(C)) {
825  // Initializers for globals are handled explicitly elsewhere.
826  } else if (C->getNumOperands()) {
827  // If a constant has operands, enumerate them. This makes sure that if a
828  // constant has uses (for example an array of const ints), that they are
829  // inserted also.
830 
831  // We prefer to enumerate them with values before we enumerate the user
832  // itself. This makes it more likely that we can avoid forward references
833  // in the reader. We know that there can be no cycles in the constants
834  // graph that don't go through a global variable.
835  for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
836  I != E; ++I)
837  if (!isa<BasicBlock>(*I)) // Don't enumerate BB operand to BlockAddress.
838  EnumerateValue(*I);
839 
840  // Finally, add the value. Doing this could make the ValueID reference be
841  // dangling, don't reuse it.
842  Values.push_back(std::make_pair(V, 1U));
843  ValueMap[V] = Values.size();
844  return;
845  }
846  }
847 
848  // Add the value.
849  Values.push_back(std::make_pair(V, 1U));
850  ValueID = Values.size();
851 }
852 
853 
854 void ValueEnumerator::EnumerateType(Type *Ty) {
855  unsigned *TypeID = &TypeMap[Ty];
856 
857  // We've already seen this type.
858  if (*TypeID)
859  return;
860 
861  // If it is a non-anonymous struct, mark the type as being visited so that we
862  // don't recursively visit it. This is safe because we allow forward
863  // references of these in the bitcode reader.
864  if (StructType *STy = dyn_cast<StructType>(Ty))
865  if (!STy->isLiteral())
866  *TypeID = ~0U;
867 
868  // Enumerate all of the subtypes before we enumerate this type. This ensures
869  // that the type will be enumerated in an order that can be directly built.
870  for (Type *SubTy : Ty->subtypes())
871  EnumerateType(SubTy);
872 
873  // Refresh the TypeID pointer in case the table rehashed.
874  TypeID = &TypeMap[Ty];
875 
876  // Check to see if we got the pointer another way. This can happen when
877  // enumerating recursive types that hit the base case deeper than they start.
878  //
879  // If this is actually a struct that we are treating as forward ref'able,
880  // then emit the definition now that all of its contents are available.
881  if (*TypeID && *TypeID != ~0U)
882  return;
883 
884  // Add this type now that its contents are all happily enumerated.
885  Types.push_back(Ty);
886 
887  *TypeID = Types.size();
888 }
889 
890 // Enumerate the types for the specified value. If the value is a constant,
891 // walk through it, enumerating the types of the constant.
892 void ValueEnumerator::EnumerateOperandType(const Value *V) {
893  EnumerateType(V->getType());
894 
895  assert(!isa<MetadataAsValue>(V) && "Unexpected metadata operand");
896 
897  const Constant *C = dyn_cast<Constant>(V);
898  if (!C)
899  return;
900 
901  // If this constant is already enumerated, ignore it, we know its type must
902  // be enumerated.
903  if (ValueMap.count(C))
904  return;
905 
906  // This constant may have operands, make sure to enumerate the types in
907  // them.
908  for (const Value *Op : C->operands()) {
909  // Don't enumerate basic blocks here, this happens as operands to
910  // blockaddress.
911  if (isa<BasicBlock>(Op))
912  continue;
913 
914  EnumerateOperandType(Op);
915  }
916 }
917 
918 void ValueEnumerator::EnumerateAttributes(AttributeList PAL) {
919  if (PAL.isEmpty()) return; // null is always 0.
920 
921  // Do a lookup.
922  unsigned &Entry = AttributeListMap[PAL];
923  if (Entry == 0) {
924  // Never saw this before, add it.
925  AttributeLists.push_back(PAL);
926  Entry = AttributeLists.size();
927  }
928 
929  // Do lookups for all attribute groups.
930  for (unsigned i = PAL.index_begin(), e = PAL.index_end(); i != e; ++i) {
931  AttributeSet AS = PAL.getAttributes(i);
932  if (!AS.hasAttributes())
933  continue;
934  IndexAndAttrSet Pair = {i, AS};
935  unsigned &Entry = AttributeGroupMap[Pair];
936  if (Entry == 0) {
937  AttributeGroups.push_back(Pair);
938  Entry = AttributeGroups.size();
939  }
940  }
941 }
942 
944  InstructionCount = 0;
945  NumModuleValues = Values.size();
946 
947  // Add global metadata to the function block. This doesn't include
948  // LocalAsMetadata.
949  incorporateFunctionMetadata(F);
950 
951  // Adding function arguments to the value table.
952  for (const auto &I : F.args()) {
953  EnumerateValue(&I);
954  if (I.hasAttribute(Attribute::ByVal))
955  EnumerateType(I.getParamByValType());
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:366
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:551
Tracking metadata reference owned by Metadata.
Definition: Metadata.h:710
This class provides a symbol table of name/value pairs.
ArrayRef< Type * > subtypes() const
Definition: Type.h:316
iterator_range< use_iterator > uses()
Definition: Value.h:374
raw_ostream & errs()
This returns a reference to a raw_ostream for standard error.
bool isDistinct() const
Definition: Metadata.h:942
static unsigned getMetadataTypeOrder(const Metadata *MD)
This class represents an incoming formal argument to a Function.
Definition: Argument.h:29
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:1080
This class represents lattice values for constants.
Definition: AllocatorList.h:23
#define LLVM_DUMP_METHOD
Mark debug helper function definitions like dump() that should not be stripped from debug builds...
Definition: Compiler.h:473
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:65
amdgpu Simplify well known AMD library false FunctionCallee Value const Twine & Name
std::pair< unsigned, AttributeSet > IndexAndAttrSet
Attribute groups as encoded in bitcode are almost AttributeSets, but they include the AttributeList i...
This file contains the declarations for metadata subclasses.
void setInstructionID(const Instruction *I)
unsigned second
Metadata node.
Definition: Metadata.h:863
F(f)
static Type * getMetadataTy(LLVMContext &C)
Definition: Type.cpp:165
unsigned index_end() const
Definition: Attributes.h:657
This defines the Use class.
void reserve(size_type N)
Definition: SmallVector.h:369
static void predictValueUseListOrderImpl(const Value *V, const Function *F, unsigned ID, const OrderMap &OM, UseListOrderStack &Stack)
op_iterator op_end() const
Definition: Metadata.h:1062
op_iterator op_begin()
Definition: User.h:229
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:221
A tuple of MDNodes.
Definition: Metadata.h:1325
Class to represent struct types.
Definition: DerivedTypes.h:233
A Use represents the edge between a Value definition and its users.
Definition: Use.h:55
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:54
uint64_t computeBitsRequiredForTypeIndicies() const
unsigned getNumOperands() const
Definition: Metadata.cpp:1076
static const uint16_t * lookup(unsigned opcode, unsigned domain, ArrayRef< uint16_t[3]> Table)
op_iterator op_begin() const
Definition: Metadata.h:1058
unsigned idFor(const T &Entry) const
idFor - return the ID for an existing entry.
Definition: UniqueVector.h:57
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:245
reverse_iterator rend()
Definition: Module.h:604
op_range operands() const
Definition: Metadata.h:1066
iterator find(const KeyT &Val)
Definition: ValueMap.h:161
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:176
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:140
bool erase(const KeyT &Val)
Definition: DenseMap.h:298
bool hasName() const
Definition: Value.h:251
LLVM Basic Block Representation.
Definition: BasicBlock.h:57
static void push(SmallVectorImpl< uint64_t > &R, StringRef Str)
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
This is an important base class in LLVM.
Definition: Constant.h:41
void print(raw_ostream &OS, const ValueMapType &Map, const char *Name) const
unsigned getInstructionID(const Instruction *I) const
std::vector< UseListOrder > UseListOrderStack
Definition: UseListOrder.h:39
ValueEnumerator(const Module &M, bool ShouldPreserveUseListOrder)
iterator_range< named_metadata_iterator > named_metadata()
Definition: Module.h:723
op_iterator op_end()
Definition: User.h:231
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:4278
static OrderMap orderModule(const Module &M)
op_range operands()
Definition: User.h:237
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:1205
Metadata wrapper in the Value hierarchy.
Definition: Metadata.h:173
size_t size() const
Definition: SmallVector.h:52
Value * getValue() const
Definition: Metadata.h:378
unsigned first
void sort(IteratorTy Start, IteratorTy End)
Definition: STLExtras.h:1107
reverse_iterator rbegin()
Definition: Module.h:602
iterator end()
Definition: ValueMap.h:141
void print(raw_ostream &OS, const Module *M=nullptr, bool IsForDebug=false) const
Print.
Definition: AsmWriter.cpp:4407
unsigned getNumOperands() const
Definition: User.h:191
See the file comment.
Definition: ValueMap.h:85
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:1158
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:837
Module.h This file contains the declarations for the Module class.
const DataFlowGraph & G
Definition: RDFGraph.cpp:202
LLVM_NODISCARD T pop_back_val()
Definition: SmallVector.h:374
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:940
unsigned getTypeID(Type *T) const
UseListOrderStack UseListOrders
use_iterator use_begin()
Definition: Value.h:358
unsigned getNumUses() const
This method computes the number of uses of this Value.
Definition: Value.cpp:160
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:40
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:55
iterator begin()
Definition: DenseMap.h:99
StringRef getName() const
Return a constant reference to the value&#39;s name.
Definition: Value.cpp:214
const Function * getParent() const
Return the enclosing method, or null if none.
Definition: BasicBlock.h:106
const NodeList & List
Definition: RDFGraph.cpp:201
#define I(x, y, z)
Definition: MD5.cpp:58
#define N
iterator end()
Definition: DenseMap.h:108
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:332
iterator_range< ifunc_iterator > ifuncs()
Definition: Module.h:645
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:211
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:231
size_type count(const KeyT &Val) const
Return 1 if the specified key is in the map, 0 otherwise.
Definition: ValueMap.h:157
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
bool hasAttributes() const
Return true if attributes exists in this set.
Definition: Attributes.h:274
void stable_sort(R &&Range)
Definition: STLExtras.h:1301
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:45
iterator_range< global_iterator > globals()
Definition: Module.h:587
unsigned getComdatID(const Comdat *C) const
bool isEmpty() const
Return true if there are no attributes.
Definition: Attributes.h:669
Root of the metadata hierarchy.
Definition: Metadata.h:57
bool use_empty() const
Definition: Value.h:342
iterator_range< arg_iterator > args()
Definition: Function.h:719
unsigned index_begin() const
Use these to iterate over the valid attribute indices.
Definition: Attributes.h:656
bool erase(const KeyT &Val)
Definition: ValueMap.h:196
iterator_range< alias_iterator > aliases()
Definition: Module.h:627