LLVM  4.0.0
RegionInfoImpl.h
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1 //===- RegionInfoImpl.h - SESE region detection analysis --------*- C++ -*-===//
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 // Detects single entry single exit regions in the control flow graph.
10 //===----------------------------------------------------------------------===//
11 
12 #ifndef LLVM_ANALYSIS_REGIONINFOIMPL_H
13 #define LLVM_ANALYSIS_REGIONINFOIMPL_H
14 
17 #include "llvm/Analysis/LoopInfo.h"
21 #include "llvm/Support/Debug.h"
23 #include <algorithm>
24 #include <iterator>
25 #include <set>
26 
27 namespace llvm {
28 
29 #define DEBUG_TYPE "region"
30 
31 //===----------------------------------------------------------------------===//
32 /// RegionBase Implementation
33 template <class Tr>
35  typename Tr::RegionInfoT *RInfo, DomTreeT *dt,
36  RegionT *Parent)
37  : RegionNodeBase<Tr>(Parent, Entry, 1), RI(RInfo), DT(dt), exit(Exit) {}
38 
39 template <class Tr>
41  // Only clean the cache for this Region. Caches of child Regions will be
42  // cleaned when the child Regions are deleted.
43  BBNodeMap.clear();
44 }
45 
46 template <class Tr>
48  this->entry.setPointer(BB);
49 }
50 
51 template <class Tr>
53  assert(exit && "No exit to replace!");
54  exit = BB;
55 }
56 
57 template <class Tr>
59  std::vector<RegionT *> RegionQueue;
60  BlockT *OldEntry = getEntry();
61 
62  RegionQueue.push_back(static_cast<RegionT *>(this));
63  while (!RegionQueue.empty()) {
64  RegionT *R = RegionQueue.back();
65  RegionQueue.pop_back();
66 
67  R->replaceEntry(NewEntry);
68  for (std::unique_ptr<RegionT> &Child : *R) {
69  if (Child->getEntry() == OldEntry)
70  RegionQueue.push_back(Child.get());
71  }
72  }
73 }
74 
75 template <class Tr>
77  std::vector<RegionT *> RegionQueue;
78  BlockT *OldExit = getExit();
79 
80  RegionQueue.push_back(static_cast<RegionT *>(this));
81  while (!RegionQueue.empty()) {
82  RegionT *R = RegionQueue.back();
83  RegionQueue.pop_back();
84 
85  R->replaceExit(NewExit);
86  for (std::unique_ptr<RegionT> &Child : *R) {
87  if (Child->getExit() == OldExit)
88  RegionQueue.push_back(Child.get());
89  }
90  }
91 }
92 
93 template <class Tr>
94 bool RegionBase<Tr>::contains(const BlockT *B) const {
95  BlockT *BB = const_cast<BlockT *>(B);
96 
97  if (!DT->getNode(BB))
98  return false;
99 
100  BlockT *entry = getEntry(), *exit = getExit();
101 
102  // Toplevel region.
103  if (!exit)
104  return true;
105 
106  return (DT->dominates(entry, BB) &&
107  !(DT->dominates(exit, BB) && DT->dominates(entry, exit)));
108 }
109 
110 template <class Tr>
111 bool RegionBase<Tr>::contains(const LoopT *L) const {
112  // BBs that are not part of any loop are element of the Loop
113  // described by the NULL pointer. This loop is not part of any region,
114  // except if the region describes the whole function.
115  if (!L)
116  return getExit() == nullptr;
117 
118  if (!contains(L->getHeader()))
119  return false;
120 
121  SmallVector<BlockT *, 8> ExitingBlocks;
122  L->getExitingBlocks(ExitingBlocks);
123 
124  for (BlockT *BB : ExitingBlocks) {
125  if (!contains(BB))
126  return false;
127  }
128 
129  return true;
130 }
131 
132 template <class Tr>
133 typename Tr::LoopT *RegionBase<Tr>::outermostLoopInRegion(LoopT *L) const {
134  if (!contains(L))
135  return nullptr;
136 
137  while (L && contains(L->getParentLoop())) {
138  L = L->getParentLoop();
139  }
140 
141  return L;
142 }
143 
144 template <class Tr>
145 typename Tr::LoopT *RegionBase<Tr>::outermostLoopInRegion(LoopInfoT *LI,
146  BlockT *BB) const {
147  assert(LI && BB && "LI and BB cannot be null!");
148  LoopT *L = LI->getLoopFor(BB);
149  return outermostLoopInRegion(L);
150 }
151 
152 template <class Tr>
153 typename RegionBase<Tr>::BlockT *RegionBase<Tr>::getEnteringBlock() const {
154  BlockT *entry = getEntry();
155  BlockT *enteringBlock = nullptr;
156 
157  for (BlockT *Pred : make_range(InvBlockTraits::child_begin(entry),
158  InvBlockTraits::child_end(entry))) {
159  if (DT->getNode(Pred) && !contains(Pred)) {
160  if (enteringBlock)
161  return nullptr;
162 
163  enteringBlock = Pred;
164  }
165  }
166 
167  return enteringBlock;
168 }
169 
170 template <class Tr>
171 typename RegionBase<Tr>::BlockT *RegionBase<Tr>::getExitingBlock() const {
172  BlockT *exit = getExit();
173  BlockT *exitingBlock = nullptr;
174 
175  if (!exit)
176  return nullptr;
177 
178  for (BlockT *Pred : make_range(InvBlockTraits::child_begin(exit),
179  InvBlockTraits::child_end(exit))) {
180  if (contains(Pred)) {
181  if (exitingBlock)
182  return nullptr;
183 
184  exitingBlock = Pred;
185  }
186  }
187 
188  return exitingBlock;
189 }
190 
191 template <class Tr>
193  return !isTopLevelRegion() && getEnteringBlock() && getExitingBlock();
194 }
195 
196 template <class Tr>
197 std::string RegionBase<Tr>::getNameStr() const {
198  std::string exitName;
199  std::string entryName;
200 
201  if (getEntry()->getName().empty()) {
202  raw_string_ostream OS(entryName);
203 
204  getEntry()->printAsOperand(OS, false);
205  } else
206  entryName = getEntry()->getName();
207 
208  if (getExit()) {
209  if (getExit()->getName().empty()) {
210  raw_string_ostream OS(exitName);
211 
212  getExit()->printAsOperand(OS, false);
213  } else
214  exitName = getExit()->getName();
215  } else
216  exitName = "<Function Return>";
217 
218  return entryName + " => " + exitName;
219 }
220 
221 template <class Tr>
222 void RegionBase<Tr>::verifyBBInRegion(BlockT *BB) const {
223  if (!contains(BB))
224  llvm_unreachable("Broken region found: enumerated BB not in region!");
225 
226  BlockT *entry = getEntry(), *exit = getExit();
227 
228  for (BlockT *Succ :
229  make_range(BlockTraits::child_begin(BB), BlockTraits::child_end(BB))) {
230  if (!contains(Succ) && exit != Succ)
231  llvm_unreachable("Broken region found: edges leaving the region must go "
232  "to the exit node!");
233  }
234 
235  if (entry != BB) {
236  for (BlockT *Pred : make_range(InvBlockTraits::child_begin(BB),
237  InvBlockTraits::child_end(BB))) {
238  if (!contains(Pred))
239  llvm_unreachable("Broken region found: edges entering the region must "
240  "go to the entry node!");
241  }
242  }
243 }
244 
245 template <class Tr>
246 void RegionBase<Tr>::verifyWalk(BlockT *BB, std::set<BlockT *> *visited) const {
247  BlockT *exit = getExit();
248 
249  visited->insert(BB);
250 
251  verifyBBInRegion(BB);
252 
253  for (BlockT *Succ :
254  make_range(BlockTraits::child_begin(BB), BlockTraits::child_end(BB))) {
255  if (Succ != exit && visited->find(Succ) == visited->end())
256  verifyWalk(Succ, visited);
257  }
258 }
259 
260 template <class Tr>
262  // Only do verification when user wants to, otherwise this expensive check
263  // will be invoked by PMDataManager::verifyPreservedAnalysis when
264  // a regionpass (marked PreservedAll) finish.
266  return;
267 
268  std::set<BlockT *> visited;
269  verifyWalk(getEntry(), &visited);
270 }
271 
272 template <class Tr>
274  for (const std::unique_ptr<RegionT> &R : *this)
275  R->verifyRegionNest();
276 
277  verifyRegion();
278 }
279 
280 template <class Tr>
282  return GraphTraits<RegionT *>::nodes_begin(static_cast<RegionT *>(this));
283 }
284 
285 template <class Tr>
287  return GraphTraits<RegionT *>::nodes_end(static_cast<RegionT *>(this));
288 }
289 
290 template <class Tr>
294  static_cast<const RegionT *>(this));
295 }
296 
297 template <class Tr>
301  static_cast<const RegionT *>(this));
302 }
303 
304 template <class Tr>
305 typename Tr::RegionT *RegionBase<Tr>::getSubRegionNode(BlockT *BB) const {
306  typedef typename Tr::RegionT RegionT;
307  RegionT *R = RI->getRegionFor(BB);
308 
309  if (!R || R == this)
310  return nullptr;
311 
312  // If we pass the BB out of this region, that means our code is broken.
313  assert(contains(R) && "BB not in current region!");
314 
315  while (contains(R->getParent()) && R->getParent() != this)
316  R = R->getParent();
317 
318  if (R->getEntry() != BB)
319  return nullptr;
320 
321  return R;
322 }
323 
324 template <class Tr>
325 typename Tr::RegionNodeT *RegionBase<Tr>::getBBNode(BlockT *BB) const {
326  assert(contains(BB) && "Can get BB node out of this region!");
327 
328  typename BBNodeMapT::const_iterator at = BBNodeMap.find(BB);
329 
330  if (at == BBNodeMap.end()) {
331  auto Deconst = const_cast<RegionBase<Tr> *>(this);
332  typename BBNodeMapT::value_type V = {
333  BB, make_unique<RegionNodeT>(static_cast<RegionT *>(Deconst), BB)};
334  at = BBNodeMap.insert(std::move(V)).first;
335  }
336  return at->second.get();
337 }
338 
339 template <class Tr>
340 typename Tr::RegionNodeT *RegionBase<Tr>::getNode(BlockT *BB) const {
341  assert(contains(BB) && "Can get BB node out of this region!");
342  if (RegionT *Child = getSubRegionNode(BB))
343  return Child->getNode();
344 
345  return getBBNode(BB);
346 }
347 
348 template <class Tr>
350  for (std::unique_ptr<RegionT> &R : *this) {
351  R->parent = To;
352  To->children.push_back(std::move(R));
353  }
354  children.clear();
355 }
356 
357 template <class Tr>
358 void RegionBase<Tr>::addSubRegion(RegionT *SubRegion, bool moveChildren) {
359  assert(!SubRegion->parent && "SubRegion already has a parent!");
360  assert(find_if(*this,
361  [&](const std::unique_ptr<RegionT> &R) {
362  return R.get() == SubRegion;
363  }) == children.end() &&
364  "Subregion already exists!");
365 
366  SubRegion->parent = static_cast<RegionT *>(this);
367  children.push_back(std::unique_ptr<RegionT>(SubRegion));
368 
369  if (!moveChildren)
370  return;
371 
372  assert(SubRegion->children.empty() &&
373  "SubRegions that contain children are not supported");
374 
375  for (RegionNodeT *Element : elements()) {
376  if (!Element->isSubRegion()) {
377  BlockT *BB = Element->template getNodeAs<BlockT>();
378 
379  if (SubRegion->contains(BB))
380  RI->setRegionFor(BB, SubRegion);
381  }
382  }
383 
384  std::vector<std::unique_ptr<RegionT>> Keep;
385  for (std::unique_ptr<RegionT> &R : *this) {
386  if (SubRegion->contains(R.get()) && R.get() != SubRegion) {
387  R->parent = SubRegion;
388  SubRegion->children.push_back(std::move(R));
389  } else
390  Keep.push_back(std::move(R));
391  }
392 
393  children.clear();
394  children.insert(
395  children.begin(),
396  std::move_iterator<typename RegionSet::iterator>(Keep.begin()),
397  std::move_iterator<typename RegionSet::iterator>(Keep.end()));
398 }
399 
400 template <class Tr>
401 typename Tr::RegionT *RegionBase<Tr>::removeSubRegion(RegionT *Child) {
402  assert(Child->parent == this && "Child is not a child of this region!");
403  Child->parent = nullptr;
404  typename RegionSet::iterator I =
405  find_if(children, [&](const std::unique_ptr<RegionT> &R) {
406  return R.get() == Child;
407  });
408  assert(I != children.end() && "Region does not exit. Unable to remove.");
409  children.erase(children.begin() + (I - begin()));
410  return Child;
411 }
412 
413 template <class Tr>
414 unsigned RegionBase<Tr>::getDepth() const {
415  unsigned Depth = 0;
416 
417  for (RegionT *R = getParent(); R != nullptr; R = R->getParent())
418  ++Depth;
419 
420  return Depth;
421 }
422 
423 template <class Tr>
424 typename Tr::RegionT *RegionBase<Tr>::getExpandedRegion() const {
425  unsigned NumSuccessors = Tr::getNumSuccessors(exit);
426 
427  if (NumSuccessors == 0)
428  return nullptr;
429 
430  RegionT *R = RI->getRegionFor(exit);
431 
432  if (R->getEntry() != exit) {
433  for (BlockT *Pred : make_range(InvBlockTraits::child_begin(getExit()),
434  InvBlockTraits::child_end(getExit())))
435  if (!contains(Pred))
436  return nullptr;
437  if (Tr::getNumSuccessors(exit) == 1)
438  return new RegionT(getEntry(), *BlockTraits::child_begin(exit), RI, DT);
439  return nullptr;
440  }
441 
442  while (R->getParent() && R->getParent()->getEntry() == exit)
443  R = R->getParent();
444 
445  for (BlockT *Pred : make_range(InvBlockTraits::child_begin(getExit()),
446  InvBlockTraits::child_end(getExit()))) {
447  if (!(contains(Pred) || R->contains(Pred)))
448  return nullptr;
449  }
450 
451  return new RegionT(getEntry(), R->getExit(), RI, DT);
452 }
453 
454 template <class Tr>
455 void RegionBase<Tr>::print(raw_ostream &OS, bool print_tree, unsigned level,
456  PrintStyle Style) const {
457  if (print_tree)
458  OS.indent(level * 2) << '[' << level << "] " << getNameStr();
459  else
460  OS.indent(level * 2) << getNameStr();
461 
462  OS << '\n';
463 
464  if (Style != PrintNone) {
465  OS.indent(level * 2) << "{\n";
466  OS.indent(level * 2 + 2);
467 
468  if (Style == PrintBB) {
469  for (const auto *BB : blocks())
470  OS << BB->getName() << ", "; // TODO: remove the last ","
471  } else if (Style == PrintRN) {
472  for (const RegionNodeT *Element : elements()) {
473  OS << *Element << ", "; // TODO: remove the last ",
474  }
475  }
476 
477  OS << '\n';
478  }
479 
480  if (print_tree) {
481  for (const std::unique_ptr<RegionT> &R : *this)
482  R->print(OS, print_tree, level + 1, Style);
483  }
484 
485  if (Style != PrintNone)
486  OS.indent(level * 2) << "} \n";
487 }
488 
489 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
490 template <class Tr>
491 void RegionBase<Tr>::dump() const {
492  print(dbgs(), true, getDepth(), RegionInfoBase<Tr>::printStyle);
493 }
494 #endif
495 
496 template <class Tr>
498  BBNodeMap.clear();
499  for (std::unique_ptr<RegionT> &R : *this)
500  R->clearNodeCache();
501 }
502 
503 //===----------------------------------------------------------------------===//
504 // RegionInfoBase implementation
505 //
506 
507 template <class Tr>
509  : TopLevelRegion(nullptr) {}
510 
511 template <class Tr>
512 RegionInfoBase<Tr>::~RegionInfoBase() {
513  releaseMemory();
514 }
515 
516 template <class Tr>
517 void RegionInfoBase<Tr>::verifyBBMap(const RegionT *R) const {
518  assert(R && "Re must be non-null");
519  for (const typename Tr::RegionNodeT *Element : R->elements()) {
520  if (Element->isSubRegion()) {
521  const RegionT *SR = Element->template getNodeAs<RegionT>();
522  verifyBBMap(SR);
523  } else {
524  BlockT *BB = Element->template getNodeAs<BlockT>();
525  if (getRegionFor(BB) != R)
526  llvm_unreachable("BB map does not match region nesting");
527  }
528  }
529 }
530 
531 template <class Tr>
532 bool RegionInfoBase<Tr>::isCommonDomFrontier(BlockT *BB, BlockT *entry,
533  BlockT *exit) const {
534  for (BlockT *P : make_range(InvBlockTraits::child_begin(BB),
535  InvBlockTraits::child_end(BB))) {
536  if (DT->dominates(entry, P) && !DT->dominates(exit, P))
537  return false;
538  }
539 
540  return true;
541 }
542 
543 template <class Tr>
544 bool RegionInfoBase<Tr>::isRegion(BlockT *entry, BlockT *exit) const {
545  assert(entry && exit && "entry and exit must not be null!");
546  typedef typename DomFrontierT::DomSetType DST;
547 
548  DST *entrySuccs = &DF->find(entry)->second;
549 
550  // Exit is the header of a loop that contains the entry. In this case,
551  // the dominance frontier must only contain the exit.
552  if (!DT->dominates(entry, exit)) {
553  for (typename DST::iterator SI = entrySuccs->begin(),
554  SE = entrySuccs->end();
555  SI != SE; ++SI) {
556  if (*SI != exit && *SI != entry)
557  return false;
558  }
559 
560  return true;
561  }
562 
563  DST *exitSuccs = &DF->find(exit)->second;
564 
565  // Do not allow edges leaving the region.
566  for (BlockT *Succ : *entrySuccs) {
567  if (Succ == exit || Succ == entry)
568  continue;
569  if (exitSuccs->find(Succ) == exitSuccs->end())
570  return false;
571  if (!isCommonDomFrontier(Succ, entry, exit))
572  return false;
573  }
574 
575  // Do not allow edges pointing into the region.
576  for (BlockT *Succ : *exitSuccs) {
577  if (DT->properlyDominates(entry, Succ) && Succ != exit)
578  return false;
579  }
580 
581  return true;
582 }
583 
584 template <class Tr>
585 void RegionInfoBase<Tr>::insertShortCut(BlockT *entry, BlockT *exit,
586  BBtoBBMap *ShortCut) const {
587  assert(entry && exit && "entry and exit must not be null!");
588 
589  typename BBtoBBMap::iterator e = ShortCut->find(exit);
590 
591  if (e == ShortCut->end())
592  // No further region at exit available.
593  (*ShortCut)[entry] = exit;
594  else {
595  // We found a region e that starts at exit. Therefore (entry, e->second)
596  // is also a region, that is larger than (entry, exit). Insert the
597  // larger one.
598  BlockT *BB = e->second;
599  (*ShortCut)[entry] = BB;
600  }
601 }
602 
603 template <class Tr>
604 typename Tr::DomTreeNodeT *
605 RegionInfoBase<Tr>::getNextPostDom(DomTreeNodeT *N, BBtoBBMap *ShortCut) const {
606  typename BBtoBBMap::iterator e = ShortCut->find(N->getBlock());
607 
608  if (e == ShortCut->end())
609  return N->getIDom();
610 
611  return PDT->getNode(e->second)->getIDom();
612 }
613 
614 template <class Tr>
615 bool RegionInfoBase<Tr>::isTrivialRegion(BlockT *entry, BlockT *exit) const {
616  assert(entry && exit && "entry and exit must not be null!");
617 
618  unsigned num_successors =
619  BlockTraits::child_end(entry) - BlockTraits::child_begin(entry);
620 
621  if (num_successors <= 1 && exit == *(BlockTraits::child_begin(entry)))
622  return true;
623 
624  return false;
625 }
626 
627 template <class Tr>
628 typename Tr::RegionT *RegionInfoBase<Tr>::createRegion(BlockT *entry,
629  BlockT *exit) {
630  assert(entry && exit && "entry and exit must not be null!");
631 
632  if (isTrivialRegion(entry, exit))
633  return nullptr;
634 
635  RegionT *region =
636  new RegionT(entry, exit, static_cast<RegionInfoT *>(this), DT);
637  BBtoRegion.insert({entry, region});
638 
639 #ifdef EXPENSIVE_CHECKS
640  region->verifyRegion();
641 #else
642  DEBUG(region->verifyRegion());
643 #endif
644 
645  updateStatistics(region);
646  return region;
647 }
648 
649 template <class Tr>
650 void RegionInfoBase<Tr>::findRegionsWithEntry(BlockT *entry,
651  BBtoBBMap *ShortCut) {
652  assert(entry);
653 
654  DomTreeNodeT *N = PDT->getNode(entry);
655  if (!N)
656  return;
657 
658  RegionT *lastRegion = nullptr;
659  BlockT *lastExit = entry;
660 
661  // As only a BasicBlock that postdominates entry can finish a region, walk the
662  // post dominance tree upwards.
663  while ((N = getNextPostDom(N, ShortCut))) {
664  BlockT *exit = N->getBlock();
665 
666  if (!exit)
667  break;
668 
669  if (isRegion(entry, exit)) {
670  RegionT *newRegion = createRegion(entry, exit);
671 
672  if (lastRegion)
673  newRegion->addSubRegion(lastRegion);
674 
675  lastRegion = newRegion;
676  lastExit = exit;
677  }
678 
679  // This can never be a region, so stop the search.
680  if (!DT->dominates(entry, exit))
681  break;
682  }
683 
684  // Tried to create regions from entry to lastExit. Next time take a
685  // shortcut from entry to lastExit.
686  if (lastExit != entry)
687  insertShortCut(entry, lastExit, ShortCut);
688 }
689 
690 template <class Tr>
691 void RegionInfoBase<Tr>::scanForRegions(FuncT &F, BBtoBBMap *ShortCut) {
692  typedef typename std::add_pointer<FuncT>::type FuncPtrT;
693  BlockT *entry = GraphTraits<FuncPtrT>::getEntryNode(&F);
694  DomTreeNodeT *N = DT->getNode(entry);
695 
696  // Iterate over the dominance tree in post order to start with the small
697  // regions from the bottom of the dominance tree. If the small regions are
698  // detected first, detection of bigger regions is faster, as we can jump
699  // over the small regions.
700  for (auto DomNode : post_order(N))
701  findRegionsWithEntry(DomNode->getBlock(), ShortCut);
702 }
703 
704 template <class Tr>
705 typename Tr::RegionT *RegionInfoBase<Tr>::getTopMostParent(RegionT *region) {
706  while (region->getParent())
707  region = region->getParent();
708 
709  return region;
710 }
711 
712 template <class Tr>
713 void RegionInfoBase<Tr>::buildRegionsTree(DomTreeNodeT *N, RegionT *region) {
714  BlockT *BB = N->getBlock();
715 
716  // Passed region exit
717  while (BB == region->getExit())
718  region = region->getParent();
719 
720  typename BBtoRegionMap::iterator it = BBtoRegion.find(BB);
721 
722  // This basic block is a start block of a region. It is already in the
723  // BBtoRegion relation. Only the child basic blocks have to be updated.
724  if (it != BBtoRegion.end()) {
725  RegionT *newRegion = it->second;
726  region->addSubRegion(getTopMostParent(newRegion));
727  region = newRegion;
728  } else {
729  BBtoRegion[BB] = region;
730  }
731 
732  for (DomTreeNodeBase<BlockT> *C : *N) {
733  buildRegionsTree(C, region);
734  }
735 }
736 
737 #ifdef EXPENSIVE_CHECKS
738 template <class Tr>
739 bool RegionInfoBase<Tr>::VerifyRegionInfo = true;
740 #else
741 template <class Tr>
742 bool RegionInfoBase<Tr>::VerifyRegionInfo = false;
743 #endif
744 
745 template <class Tr>
746 typename Tr::RegionT::PrintStyle RegionInfoBase<Tr>::printStyle =
747  RegionBase<Tr>::PrintNone;
748 
749 template <class Tr>
751  OS << "Region tree:\n";
752  TopLevelRegion->print(OS, true, 0, printStyle);
753  OS << "End region tree\n";
754 }
755 
756 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
757 template <class Tr>
758 void RegionInfoBase<Tr>::dump() const { print(dbgs()); }
759 #endif
760 
761 template <class Tr>
763  BBtoRegion.clear();
764  if (TopLevelRegion)
765  delete TopLevelRegion;
766  TopLevelRegion = nullptr;
767 }
768 
769 template <class Tr>
771  // Do only verify regions if explicitely activated using EXPENSIVE_CHECKS or
772  // -verify-region-info
774  return;
775 
776  TopLevelRegion->verifyRegionNest();
777 
778  verifyBBMap(TopLevelRegion);
779 }
780 
781 // Region pass manager support.
782 template <class Tr>
783 typename Tr::RegionT *RegionInfoBase<Tr>::getRegionFor(BlockT *BB) const {
784  typename BBtoRegionMap::const_iterator I = BBtoRegion.find(BB);
785  return I != BBtoRegion.end() ? I->second : nullptr;
786 }
787 
788 template <class Tr>
789 void RegionInfoBase<Tr>::setRegionFor(BlockT *BB, RegionT *R) {
790  BBtoRegion[BB] = R;
791 }
792 
793 template <class Tr>
794 typename Tr::RegionT *RegionInfoBase<Tr>::operator[](BlockT *BB) const {
795  return getRegionFor(BB);
796 }
797 
798 template <class Tr>
799 typename RegionInfoBase<Tr>::BlockT *
801  BlockT *Exit = nullptr;
802 
803  while (true) {
804  // Get largest region that starts at BB.
805  RegionT *R = getRegionFor(BB);
806  while (R && R->getParent() && R->getParent()->getEntry() == BB)
807  R = R->getParent();
808 
809  // Get the single exit of BB.
810  if (R && R->getEntry() == BB)
811  Exit = R->getExit();
812  else if (++BlockTraits::child_begin(BB) == BlockTraits::child_end(BB))
813  Exit = *BlockTraits::child_begin(BB);
814  else // No single exit exists.
815  return Exit;
816 
817  // Get largest region that starts at Exit.
818  RegionT *ExitR = getRegionFor(Exit);
819  while (ExitR && ExitR->getParent() &&
820  ExitR->getParent()->getEntry() == Exit)
821  ExitR = ExitR->getParent();
822 
823  for (BlockT *Pred : make_range(InvBlockTraits::child_begin(Exit),
824  InvBlockTraits::child_end(Exit))) {
825  if (!R->contains(Pred) && !ExitR->contains(Pred))
826  break;
827  }
828 
829  // This stops infinite cycles.
830  if (DT->dominates(Exit, BB))
831  break;
832 
833  BB = Exit;
834  }
835 
836  return Exit;
837 }
838 
839 template <class Tr>
840 typename Tr::RegionT *RegionInfoBase<Tr>::getCommonRegion(RegionT *A,
841  RegionT *B) const {
842  assert(A && B && "One of the Regions is NULL");
843 
844  if (A->contains(B))
845  return A;
846 
847  while (!B->contains(A))
848  B = B->getParent();
849 
850  return B;
851 }
852 
853 template <class Tr>
854 typename Tr::RegionT *
856  RegionT *ret = Regions.back();
857  Regions.pop_back();
858 
859  for (RegionT *R : Regions)
860  ret = getCommonRegion(ret, R);
861 
862  return ret;
863 }
864 
865 template <class Tr>
866 typename Tr::RegionT *
868  RegionT *ret = getRegionFor(BBs.back());
869  BBs.pop_back();
870 
871  for (BlockT *BB : BBs)
872  ret = getCommonRegion(ret, getRegionFor(BB));
873 
874  return ret;
875 }
876 
877 template <class Tr>
878 void RegionInfoBase<Tr>::calculate(FuncT &F) {
879  typedef typename std::add_pointer<FuncT>::type FuncPtrT;
880 
881  // ShortCut a function where for every BB the exit of the largest region
882  // starting with BB is stored. These regions can be threated as single BBS.
883  // This improves performance on linear CFGs.
884  BBtoBBMap ShortCut;
885 
886  scanForRegions(F, &ShortCut);
887  BlockT *BB = GraphTraits<FuncPtrT>::getEntryNode(&F);
888  buildRegionsTree(DT->getNode(BB), TopLevelRegion);
889 }
890 
891 #undef DEBUG_TYPE
892 
893 } // end namespace llvm
894 
895 #endif
MachineLoop * L
std::string getNameStr() const
Returns the name of the Region.
RegionNodeT * getNode() const
Get the RegionNode representing the current Region.
Definition: RegionInfo.h:364
Tr::RegionT RegionT
Definition: RegionInfo.h:117
bool isSimple() const
Is this a simple region?
void print(raw_ostream &OS, bool printTree=true, unsigned level=0, PrintStyle Style=PrintNone) const
Print the region.
BlockT * getExitingBlock() const
Return the first block of this region's single exit edge, if existing.
raw_ostream & indent(unsigned NumSpaces)
indent - Insert 'NumSpaces' spaces.
const_iterator begin(StringRef path)
Get begin iterator over path.
Definition: Path.cpp:233
void setRegionFor(BlockT *BB, RegionT *R)
Set the smallest region that surrounds a basic block.
Analysis that detects all canonical Regions.
Definition: RegionInfo.h:77
RegionT * getRegionFor(BlockT *BB) const
Get the smallest region that contains a BasicBlock.
return AArch64::GPR64RegClass contains(Reg)
unsigned getDepth() const
Get the nesting level of this Region.
LoopT * outermostLoopInRegion(LoopT *L) const
Get the outermost loop in the region that contains a loop.
void clearNodeCache()
Clear the cache for BB RegionNodes.
A RegionNode represents a subregion or a BasicBlock that is part of a Region.
Definition: RegionInfo.h:112
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APFloat.h:32
static StringRef getName(Value *V)
RegionNodeT * getBBNode(BlockT *BB) const
Get the BasicBlock RegionNode for a BasicBlock.
void print(raw_ostream &OS) const
BlockT * getMaxRegionExit(BlockT *BB) const
Return the exit of the maximal refined region, that starts at a BasicBlock.
PrintStyle
PrintStyle - Print region in difference ways.
Definition: RegionInfo.h:418
void verifyAnalysis() const
#define F(x, y, z)
Definition: MD5.cpp:51
static GCRegistry::Add< OcamlGC > B("ocaml","ocaml 3.10-compatible GC")
#define P(N)
void dump() const
Print the region to stderr.
void addSubRegion(RegionT *SubRegion, bool moveChildren=false)
Add a new subregion to this Region.
void replaceExit(BlockT *BB)
Replace the exit basic block of the region with the new basic block.
element_iterator element_end()
iterator_range< po_iterator< T > > post_order(const T &G)
void transferChildrenTo(RegionT *To)
Move all direct child nodes of this Region to another Region.
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
iterator_range< T > make_range(T x, T y)
Convenience function for iterating over sub-ranges.
void replaceEntryRecursive(BlockT *NewEntry)
Recursively replace the entry basic block of the region.
RegionT * getSubRegionNode(BlockT *BB) const
Get the subregion that starts at a BasicBlock.
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:843
RegionT * getExpandedRegion() const
Return a new (non-canonical) region, that is obtained by joining this region with its predecessors...
A single entry single exit Region.
Definition: RegionInfo.h:73
static GCRegistry::Add< ShadowStackGC > C("shadow-stack","Very portable GC for uncooperative code generators")
void replaceEntry(BlockT *BB)
Replace the entry basic block of the region with the new basic block.
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:132
element_iterator element_begin()
void replaceExitRecursive(BlockT *NewExit)
Recursively replace the exit basic block of the region.
BlockT * getEnteringBlock() const
Return the first block of this region's single entry edge, if existing.
#define I(x, y, z)
Definition: MD5.cpp:54
#define N
void verifyRegion() const
Verify if the region is a correct region.
~RegionBase()
Delete the Region and all its subregions.
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
RegionT * operator[](BlockT *BB) const
A shortcut for getRegionFor().
A raw_ostream that writes to an std::string.
Definition: raw_ostream.h:463
RegionT * getCommonRegion(RegionT *A, RegionT *B) const
Find the smallest region that contains two regions.
Module * getParent()
Get the module that this global value is contained inside of...
Definition: GlobalValue.h:537
bool contains(const BlockT *BB) const
Check if the region contains a BasicBlock.
static const Function * getParent(const Value *V)
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:44
#define DEBUG(X)
Definition: Debug.h:100
RegionT * removeSubRegion(RegionT *SubRegion)
Remove a subregion from this Region.
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:764
static GCRegistry::Add< ErlangGC > A("erlang","erlang-compatible garbage collector")