LLVM  10.0.0svn
CodeExtractor.cpp
Go to the documentation of this file.
1 //===- CodeExtractor.cpp - Pull code region into a new function -----------===//
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 interface to tear out a code region, such as an
10 // individual loop or a parallel section, into a new function, replacing it with
11 // a call to the new function.
12 //
13 //===----------------------------------------------------------------------===//
14 
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/Optional.h"
19 #include "llvm/ADT/STLExtras.h"
20 #include "llvm/ADT/SetVector.h"
21 #include "llvm/ADT/SmallPtrSet.h"
22 #include "llvm/ADT/SmallVector.h"
27 #include "llvm/Analysis/LoopInfo.h"
28 #include "llvm/IR/Argument.h"
29 #include "llvm/IR/Attributes.h"
30 #include "llvm/IR/BasicBlock.h"
31 #include "llvm/IR/CFG.h"
32 #include "llvm/IR/Constant.h"
33 #include "llvm/IR/Constants.h"
34 #include "llvm/IR/DataLayout.h"
35 #include "llvm/IR/DerivedTypes.h"
36 #include "llvm/IR/Dominators.h"
37 #include "llvm/IR/Function.h"
38 #include "llvm/IR/GlobalValue.h"
39 #include "llvm/IR/InstrTypes.h"
40 #include "llvm/IR/Instruction.h"
41 #include "llvm/IR/Instructions.h"
42 #include "llvm/IR/IntrinsicInst.h"
43 #include "llvm/IR/Intrinsics.h"
44 #include "llvm/IR/LLVMContext.h"
45 #include "llvm/IR/MDBuilder.h"
46 #include "llvm/IR/Module.h"
47 #include "llvm/IR/PatternMatch.h"
48 #include "llvm/IR/Type.h"
49 #include "llvm/IR/User.h"
50 #include "llvm/IR/Value.h"
51 #include "llvm/IR/Verifier.h"
52 #include "llvm/Pass.h"
55 #include "llvm/Support/Casting.h"
57 #include "llvm/Support/Debug.h"
62 #include <cassert>
63 #include <cstdint>
64 #include <iterator>
65 #include <map>
66 #include <set>
67 #include <utility>
68 #include <vector>
69 
70 using namespace llvm;
71 using namespace llvm::PatternMatch;
73 
74 #define DEBUG_TYPE "code-extractor"
75 
76 // Provide a command-line option to aggregate function arguments into a struct
77 // for functions produced by the code extractor. This is useful when converting
78 // extracted functions to pthread-based code, as only one argument (void*) can
79 // be passed in to pthread_create().
80 static cl::opt<bool>
81 AggregateArgsOpt("aggregate-extracted-args", cl::Hidden,
82  cl::desc("Aggregate arguments to code-extracted functions"));
83 
84 /// Test whether a block is valid for extraction.
85 static bool isBlockValidForExtraction(const BasicBlock &BB,
86  const SetVector<BasicBlock *> &Result,
87  bool AllowVarArgs, bool AllowAlloca) {
88  // taking the address of a basic block moved to another function is illegal
89  if (BB.hasAddressTaken())
90  return false;
91 
92  // don't hoist code that uses another basicblock address, as it's likely to
93  // lead to unexpected behavior, like cross-function jumps
96 
97  for (Instruction const &Inst : BB)
98  ToVisit.push_back(&Inst);
99 
100  while (!ToVisit.empty()) {
101  User const *Curr = ToVisit.pop_back_val();
102  if (!Visited.insert(Curr).second)
103  continue;
104  if (isa<BlockAddress const>(Curr))
105  return false; // even a reference to self is likely to be not compatible
106 
107  if (isa<Instruction>(Curr) && cast<Instruction>(Curr)->getParent() != &BB)
108  continue;
109 
110  for (auto const &U : Curr->operands()) {
111  if (auto *UU = dyn_cast<User>(U))
112  ToVisit.push_back(UU);
113  }
114  }
115 
116  // If explicitly requested, allow vastart and alloca. For invoke instructions
117  // verify that extraction is valid.
118  for (BasicBlock::const_iterator I = BB.begin(), E = BB.end(); I != E; ++I) {
119  if (isa<AllocaInst>(I)) {
120  if (!AllowAlloca)
121  return false;
122  continue;
123  }
124 
125  if (const auto *II = dyn_cast<InvokeInst>(I)) {
126  // Unwind destination (either a landingpad, catchswitch, or cleanuppad)
127  // must be a part of the subgraph which is being extracted.
128  if (auto *UBB = II->getUnwindDest())
129  if (!Result.count(UBB))
130  return false;
131  continue;
132  }
133 
134  // All catch handlers of a catchswitch instruction as well as the unwind
135  // destination must be in the subgraph.
136  if (const auto *CSI = dyn_cast<CatchSwitchInst>(I)) {
137  if (auto *UBB = CSI->getUnwindDest())
138  if (!Result.count(UBB))
139  return false;
140  for (auto *HBB : CSI->handlers())
141  if (!Result.count(const_cast<BasicBlock*>(HBB)))
142  return false;
143  continue;
144  }
145 
146  // Make sure that entire catch handler is within subgraph. It is sufficient
147  // to check that catch return's block is in the list.
148  if (const auto *CPI = dyn_cast<CatchPadInst>(I)) {
149  for (const auto *U : CPI->users())
150  if (const auto *CRI = dyn_cast<CatchReturnInst>(U))
151  if (!Result.count(const_cast<BasicBlock*>(CRI->getParent())))
152  return false;
153  continue;
154  }
155 
156  // And do similar checks for cleanup handler - the entire handler must be
157  // in subgraph which is going to be extracted. For cleanup return should
158  // additionally check that the unwind destination is also in the subgraph.
159  if (const auto *CPI = dyn_cast<CleanupPadInst>(I)) {
160  for (const auto *U : CPI->users())
161  if (const auto *CRI = dyn_cast<CleanupReturnInst>(U))
162  if (!Result.count(const_cast<BasicBlock*>(CRI->getParent())))
163  return false;
164  continue;
165  }
166  if (const auto *CRI = dyn_cast<CleanupReturnInst>(I)) {
167  if (auto *UBB = CRI->getUnwindDest())
168  if (!Result.count(UBB))
169  return false;
170  continue;
171  }
172 
173  if (const CallInst *CI = dyn_cast<CallInst>(I)) {
174  if (const Function *F = CI->getCalledFunction()) {
175  auto IID = F->getIntrinsicID();
176  if (IID == Intrinsic::vastart) {
177  if (AllowVarArgs)
178  continue;
179  else
180  return false;
181  }
182 
183  // Currently, we miscompile outlined copies of eh_typid_for. There are
184  // proposals for fixing this in llvm.org/PR39545.
185  if (IID == Intrinsic::eh_typeid_for)
186  return false;
187  }
188  }
189  }
190 
191  return true;
192 }
193 
194 /// Build a set of blocks to extract if the input blocks are viable.
197  bool AllowVarArgs, bool AllowAlloca) {
198  assert(!BBs.empty() && "The set of blocks to extract must be non-empty");
200 
201  // Loop over the blocks, adding them to our set-vector, and aborting with an
202  // empty set if we encounter invalid blocks.
203  for (BasicBlock *BB : BBs) {
204  // If this block is dead, don't process it.
205  if (DT && !DT->isReachableFromEntry(BB))
206  continue;
207 
208  if (!Result.insert(BB))
209  llvm_unreachable("Repeated basic blocks in extraction input");
210  }
211 
212  LLVM_DEBUG(dbgs() << "Region front block: " << Result.front()->getName()
213  << '\n');
214 
215  for (auto *BB : Result) {
216  if (!isBlockValidForExtraction(*BB, Result, AllowVarArgs, AllowAlloca))
217  return {};
218 
219  // Make sure that the first block is not a landing pad.
220  if (BB == Result.front()) {
221  if (BB->isEHPad()) {
222  LLVM_DEBUG(dbgs() << "The first block cannot be an unwind block\n");
223  return {};
224  }
225  continue;
226  }
227 
228  // All blocks other than the first must not have predecessors outside of
229  // the subgraph which is being extracted.
230  for (auto *PBB : predecessors(BB))
231  if (!Result.count(PBB)) {
232  LLVM_DEBUG(dbgs() << "No blocks in this region may have entries from "
233  "outside the region except for the first block!\n"
234  << "Problematic source BB: " << BB->getName() << "\n"
235  << "Problematic destination BB: " << PBB->getName()
236  << "\n");
237  return {};
238  }
239  }
240 
241  return Result;
242 }
243 
245  bool AggregateArgs, BlockFrequencyInfo *BFI,
247  bool AllowVarArgs, bool AllowAlloca,
248  std::string Suffix)
249  : DT(DT), AggregateArgs(AggregateArgs || AggregateArgsOpt), BFI(BFI),
250  BPI(BPI), AC(AC), AllowVarArgs(AllowVarArgs),
251  Blocks(buildExtractionBlockSet(BBs, DT, AllowVarArgs, AllowAlloca)),
252  Suffix(Suffix) {}
253 
254 CodeExtractor::CodeExtractor(DominatorTree &DT, Loop &L, bool AggregateArgs,
255  BlockFrequencyInfo *BFI,
257  std::string Suffix)
258  : DT(&DT), AggregateArgs(AggregateArgs || AggregateArgsOpt), BFI(BFI),
259  BPI(BPI), AC(AC), AllowVarArgs(false),
260  Blocks(buildExtractionBlockSet(L.getBlocks(), &DT,
261  /* AllowVarArgs */ false,
262  /* AllowAlloca */ false)),
263  Suffix(Suffix) {}
264 
265 /// definedInRegion - Return true if the specified value is defined in the
266 /// extracted region.
267 static bool definedInRegion(const SetVector<BasicBlock *> &Blocks, Value *V) {
268  if (Instruction *I = dyn_cast<Instruction>(V))
269  if (Blocks.count(I->getParent()))
270  return true;
271  return false;
272 }
273 
274 /// definedInCaller - Return true if the specified value is defined in the
275 /// function being code extracted, but not in the region being extracted.
276 /// These values must be passed in as live-ins to the function.
277 static bool definedInCaller(const SetVector<BasicBlock *> &Blocks, Value *V) {
278  if (isa<Argument>(V)) return true;
279  if (Instruction *I = dyn_cast<Instruction>(V))
280  if (!Blocks.count(I->getParent()))
281  return true;
282  return false;
283 }
284 
286  BasicBlock *CommonExitBlock = nullptr;
287  auto hasNonCommonExitSucc = [&](BasicBlock *Block) {
288  for (auto *Succ : successors(Block)) {
289  // Internal edges, ok.
290  if (Blocks.count(Succ))
291  continue;
292  if (!CommonExitBlock) {
293  CommonExitBlock = Succ;
294  continue;
295  }
296  if (CommonExitBlock == Succ)
297  continue;
298 
299  return true;
300  }
301  return false;
302  };
303 
304  if (any_of(Blocks, hasNonCommonExitSucc))
305  return nullptr;
306 
307  return CommonExitBlock;
308 }
309 
311  Instruction *Addr) const {
312  AllocaInst *AI = cast<AllocaInst>(Addr->stripInBoundsConstantOffsets());
313  Function *Func = (*Blocks.begin())->getParent();
314  for (BasicBlock &BB : *Func) {
315  if (Blocks.count(&BB))
316  continue;
317  for (Instruction &II : BB) {
318  if (isa<DbgInfoIntrinsic>(II))
319  continue;
320 
321  unsigned Opcode = II.getOpcode();
322  Value *MemAddr = nullptr;
323  switch (Opcode) {
324  case Instruction::Store:
325  case Instruction::Load: {
326  if (Opcode == Instruction::Store) {
327  StoreInst *SI = cast<StoreInst>(&II);
328  MemAddr = SI->getPointerOperand();
329  } else {
330  LoadInst *LI = cast<LoadInst>(&II);
331  MemAddr = LI->getPointerOperand();
332  }
333  // Global variable can not be aliased with locals.
334  if (dyn_cast<Constant>(MemAddr))
335  break;
337  if (!isa<AllocaInst>(Base) || Base == AI)
338  return false;
339  break;
340  }
341  default: {
342  IntrinsicInst *IntrInst = dyn_cast<IntrinsicInst>(&II);
343  if (IntrInst) {
344  if (IntrInst->isLifetimeStartOrEnd())
345  break;
346  return false;
347  }
348  // Treat all the other cases conservatively if it has side effects.
349  if (II.mayHaveSideEffects())
350  return false;
351  }
352  }
353  }
354  }
355 
356  return true;
357 }
358 
359 BasicBlock *
361  BasicBlock *SinglePredFromOutlineRegion = nullptr;
362  assert(!Blocks.count(CommonExitBlock) &&
363  "Expect a block outside the region!");
364  for (auto *Pred : predecessors(CommonExitBlock)) {
365  if (!Blocks.count(Pred))
366  continue;
367  if (!SinglePredFromOutlineRegion) {
368  SinglePredFromOutlineRegion = Pred;
369  } else if (SinglePredFromOutlineRegion != Pred) {
370  SinglePredFromOutlineRegion = nullptr;
371  break;
372  }
373  }
374 
375  if (SinglePredFromOutlineRegion)
376  return SinglePredFromOutlineRegion;
377 
378 #ifndef NDEBUG
379  auto getFirstPHI = [](BasicBlock *BB) {
380  BasicBlock::iterator I = BB->begin();
381  PHINode *FirstPhi = nullptr;
382  while (I != BB->end()) {
383  PHINode *Phi = dyn_cast<PHINode>(I);
384  if (!Phi)
385  break;
386  if (!FirstPhi) {
387  FirstPhi = Phi;
388  break;
389  }
390  }
391  return FirstPhi;
392  };
393  // If there are any phi nodes, the single pred either exists or has already
394  // be created before code extraction.
395  assert(!getFirstPHI(CommonExitBlock) && "Phi not expected");
396 #endif
397 
398  BasicBlock *NewExitBlock = CommonExitBlock->splitBasicBlock(
399  CommonExitBlock->getFirstNonPHI()->getIterator());
400 
401  for (auto PI = pred_begin(CommonExitBlock), PE = pred_end(CommonExitBlock);
402  PI != PE;) {
403  BasicBlock *Pred = *PI++;
404  if (Blocks.count(Pred))
405  continue;
406  Pred->getTerminator()->replaceUsesOfWith(CommonExitBlock, NewExitBlock);
407  }
408  // Now add the old exit block to the outline region.
409  Blocks.insert(CommonExitBlock);
410  return CommonExitBlock;
411 }
412 
413 // Find the pair of life time markers for address 'Addr' that are either
414 // defined inside the outline region or can legally be shrinkwrapped into the
415 // outline region. If there are not other untracked uses of the address, return
416 // the pair of markers if found; otherwise return a pair of nullptr.
417 CodeExtractor::LifetimeMarkerInfo
418 CodeExtractor::getLifetimeMarkers(Instruction *Addr,
419  BasicBlock *ExitBlock) const {
420  LifetimeMarkerInfo Info;
421 
422  for (User *U : Addr->users()) {
423  IntrinsicInst *IntrInst = dyn_cast<IntrinsicInst>(U);
424  if (IntrInst) {
425  if (IntrInst->getIntrinsicID() == Intrinsic::lifetime_start) {
426  // Do not handle the case where Addr has multiple start markers.
427  if (Info.LifeStart)
428  return {};
429  Info.LifeStart = IntrInst;
430  }
431  if (IntrInst->getIntrinsicID() == Intrinsic::lifetime_end) {
432  if (Info.LifeEnd)
433  return {};
434  Info.LifeEnd = IntrInst;
435  }
436  continue;
437  }
438  // Find untracked uses of the address, bail.
439  if (!definedInRegion(Blocks, U))
440  return {};
441  }
442 
443  if (!Info.LifeStart || !Info.LifeEnd)
444  return {};
445 
446  Info.SinkLifeStart = !definedInRegion(Blocks, Info.LifeStart);
447  Info.HoistLifeEnd = !definedInRegion(Blocks, Info.LifeEnd);
448  // Do legality check.
449  if ((Info.SinkLifeStart || Info.HoistLifeEnd) &&
451  return {};
452 
453  // Check to see if we have a place to do hoisting, if not, bail.
454  if (Info.HoistLifeEnd && !ExitBlock)
455  return {};
456 
457  return Info;
458 }
459 
460 void CodeExtractor::findAllocas(ValueSet &SinkCands, ValueSet &HoistCands,
461  BasicBlock *&ExitBlock) const {
462  Function *Func = (*Blocks.begin())->getParent();
463  ExitBlock = getCommonExitBlock(Blocks);
464 
465  auto moveOrIgnoreLifetimeMarkers =
466  [&](const LifetimeMarkerInfo &LMI) -> bool {
467  if (!LMI.LifeStart)
468  return false;
469  if (LMI.SinkLifeStart) {
470  LLVM_DEBUG(dbgs() << "Sinking lifetime.start: " << *LMI.LifeStart
471  << "\n");
472  SinkCands.insert(LMI.LifeStart);
473  }
474  if (LMI.HoistLifeEnd) {
475  LLVM_DEBUG(dbgs() << "Hoisting lifetime.end: " << *LMI.LifeEnd << "\n");
476  HoistCands.insert(LMI.LifeEnd);
477  }
478  return true;
479  };
480 
481  for (BasicBlock &BB : *Func) {
482  if (Blocks.count(&BB))
483  continue;
484  for (Instruction &II : BB) {
485  auto *AI = dyn_cast<AllocaInst>(&II);
486  if (!AI)
487  continue;
488 
489  LifetimeMarkerInfo MarkerInfo = getLifetimeMarkers(AI, ExitBlock);
490  bool Moved = moveOrIgnoreLifetimeMarkers(MarkerInfo);
491  if (Moved) {
492  LLVM_DEBUG(dbgs() << "Sinking alloca: " << *AI << "\n");
493  SinkCands.insert(AI);
494  continue;
495  }
496 
497  // Follow any bitcasts.
499  SmallVector<LifetimeMarkerInfo, 2> BitcastLifetimeInfo;
500  for (User *U : AI->users()) {
501  if (U->stripInBoundsConstantOffsets() == AI) {
502  Instruction *Bitcast = cast<Instruction>(U);
503  LifetimeMarkerInfo LMI = getLifetimeMarkers(Bitcast, ExitBlock);
504  if (LMI.LifeStart) {
505  Bitcasts.push_back(Bitcast);
506  BitcastLifetimeInfo.push_back(LMI);
507  continue;
508  }
509  }
510 
511  // Found unknown use of AI.
512  if (!definedInRegion(Blocks, U)) {
513  Bitcasts.clear();
514  break;
515  }
516  }
517 
518  // Either no bitcasts reference the alloca or there are unknown uses.
519  if (Bitcasts.empty())
520  continue;
521 
522  LLVM_DEBUG(dbgs() << "Sinking alloca (via bitcast): " << *AI << "\n");
523  SinkCands.insert(AI);
524  for (unsigned I = 0, E = Bitcasts.size(); I != E; ++I) {
525  Instruction *BitcastAddr = Bitcasts[I];
526  const LifetimeMarkerInfo &LMI = BitcastLifetimeInfo[I];
527  assert(LMI.LifeStart &&
528  "Unsafe to sink bitcast without lifetime markers");
529  moveOrIgnoreLifetimeMarkers(LMI);
530  if (!definedInRegion(Blocks, BitcastAddr)) {
531  LLVM_DEBUG(dbgs() << "Sinking bitcast-of-alloca: " << *BitcastAddr
532  << "\n");
533  SinkCands.insert(BitcastAddr);
534  }
535  }
536  }
537  }
538 }
539 
541  const ValueSet &SinkCands) const {
542  for (BasicBlock *BB : Blocks) {
543  // If a used value is defined outside the region, it's an input. If an
544  // instruction is used outside the region, it's an output.
545  for (Instruction &II : *BB) {
546  for (User::op_iterator OI = II.op_begin(), OE = II.op_end(); OI != OE;
547  ++OI) {
548  Value *V = *OI;
549  if (!SinkCands.count(V) && definedInCaller(Blocks, V))
550  Inputs.insert(V);
551  }
552 
553  for (User *U : II.users())
554  if (!definedInRegion(Blocks, U)) {
555  Outputs.insert(&II);
556  break;
557  }
558  }
559  }
560 }
561 
562 /// severSplitPHINodesOfEntry - If a PHI node has multiple inputs from outside
563 /// of the region, we need to split the entry block of the region so that the
564 /// PHI node is easier to deal with.
565 void CodeExtractor::severSplitPHINodesOfEntry(BasicBlock *&Header) {
566  unsigned NumPredsFromRegion = 0;
567  unsigned NumPredsOutsideRegion = 0;
568 
569  if (Header != &Header->getParent()->getEntryBlock()) {
570  PHINode *PN = dyn_cast<PHINode>(Header->begin());
571  if (!PN) return; // No PHI nodes.
572 
573  // If the header node contains any PHI nodes, check to see if there is more
574  // than one entry from outside the region. If so, we need to sever the
575  // header block into two.
576  for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
577  if (Blocks.count(PN->getIncomingBlock(i)))
578  ++NumPredsFromRegion;
579  else
580  ++NumPredsOutsideRegion;
581 
582  // If there is one (or fewer) predecessor from outside the region, we don't
583  // need to do anything special.
584  if (NumPredsOutsideRegion <= 1) return;
585  }
586 
587  // Otherwise, we need to split the header block into two pieces: one
588  // containing PHI nodes merging values from outside of the region, and a
589  // second that contains all of the code for the block and merges back any
590  // incoming values from inside of the region.
591  BasicBlock *NewBB = SplitBlock(Header, Header->getFirstNonPHI(), DT);
592 
593  // We only want to code extract the second block now, and it becomes the new
594  // header of the region.
595  BasicBlock *OldPred = Header;
596  Blocks.remove(OldPred);
597  Blocks.insert(NewBB);
598  Header = NewBB;
599 
600  // Okay, now we need to adjust the PHI nodes and any branches from within the
601  // region to go to the new header block instead of the old header block.
602  if (NumPredsFromRegion) {
603  PHINode *PN = cast<PHINode>(OldPred->begin());
604  // Loop over all of the predecessors of OldPred that are in the region,
605  // changing them to branch to NewBB instead.
606  for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
607  if (Blocks.count(PN->getIncomingBlock(i))) {
609  TI->replaceUsesOfWith(OldPred, NewBB);
610  }
611 
612  // Okay, everything within the region is now branching to the right block, we
613  // just have to update the PHI nodes now, inserting PHI nodes into NewBB.
614  BasicBlock::iterator AfterPHIs;
615  for (AfterPHIs = OldPred->begin(); isa<PHINode>(AfterPHIs); ++AfterPHIs) {
616  PHINode *PN = cast<PHINode>(AfterPHIs);
617  // Create a new PHI node in the new region, which has an incoming value
618  // from OldPred of PN.
619  PHINode *NewPN = PHINode::Create(PN->getType(), 1 + NumPredsFromRegion,
620  PN->getName() + ".ce", &NewBB->front());
621  PN->replaceAllUsesWith(NewPN);
622  NewPN->addIncoming(PN, OldPred);
623 
624  // Loop over all of the incoming value in PN, moving them to NewPN if they
625  // are from the extracted region.
626  for (unsigned i = 0; i != PN->getNumIncomingValues(); ++i) {
627  if (Blocks.count(PN->getIncomingBlock(i))) {
628  NewPN->addIncoming(PN->getIncomingValue(i), PN->getIncomingBlock(i));
629  PN->removeIncomingValue(i);
630  --i;
631  }
632  }
633  }
634  }
635 }
636 
637 /// severSplitPHINodesOfExits - if PHI nodes in exit blocks have inputs from
638 /// outlined region, we split these PHIs on two: one with inputs from region
639 /// and other with remaining incoming blocks; then first PHIs are placed in
640 /// outlined region.
641 void CodeExtractor::severSplitPHINodesOfExits(
642  const SmallPtrSetImpl<BasicBlock *> &Exits) {
643  for (BasicBlock *ExitBB : Exits) {
644  BasicBlock *NewBB = nullptr;
645 
646  for (PHINode &PN : ExitBB->phis()) {
647  // Find all incoming values from the outlining region.
648  SmallVector<unsigned, 2> IncomingVals;
649  for (unsigned i = 0; i < PN.getNumIncomingValues(); ++i)
650  if (Blocks.count(PN.getIncomingBlock(i)))
651  IncomingVals.push_back(i);
652 
653  // Do not process PHI if there is one (or fewer) predecessor from region.
654  // If PHI has exactly one predecessor from region, only this one incoming
655  // will be replaced on codeRepl block, so it should be safe to skip PHI.
656  if (IncomingVals.size() <= 1)
657  continue;
658 
659  // Create block for new PHIs and add it to the list of outlined if it
660  // wasn't done before.
661  if (!NewBB) {
662  NewBB = BasicBlock::Create(ExitBB->getContext(),
663  ExitBB->getName() + ".split",
664  ExitBB->getParent(), ExitBB);
666  pred_end(ExitBB));
667  for (BasicBlock *PredBB : Preds)
668  if (Blocks.count(PredBB))
669  PredBB->getTerminator()->replaceUsesOfWith(ExitBB, NewBB);
670  BranchInst::Create(ExitBB, NewBB);
671  Blocks.insert(NewBB);
672  }
673 
674  // Split this PHI.
675  PHINode *NewPN =
676  PHINode::Create(PN.getType(), IncomingVals.size(),
677  PN.getName() + ".ce", NewBB->getFirstNonPHI());
678  for (unsigned i : IncomingVals)
679  NewPN->addIncoming(PN.getIncomingValue(i), PN.getIncomingBlock(i));
680  for (unsigned i : reverse(IncomingVals))
681  PN.removeIncomingValue(i, false);
682  PN.addIncoming(NewPN, NewBB);
683  }
684  }
685 }
686 
687 void CodeExtractor::splitReturnBlocks() {
688  for (BasicBlock *Block : Blocks)
689  if (ReturnInst *RI = dyn_cast<ReturnInst>(Block->getTerminator())) {
690  BasicBlock *New =
691  Block->splitBasicBlock(RI->getIterator(), Block->getName() + ".ret");
692  if (DT) {
693  // Old dominates New. New node dominates all other nodes dominated
694  // by Old.
695  DomTreeNode *OldNode = DT->getNode(Block);
696  SmallVector<DomTreeNode *, 8> Children(OldNode->begin(),
697  OldNode->end());
698 
699  DomTreeNode *NewNode = DT->addNewBlock(New, Block);
700 
701  for (DomTreeNode *I : Children)
702  DT->changeImmediateDominator(I, NewNode);
703  }
704  }
705 }
706 
707 /// constructFunction - make a function based on inputs and outputs, as follows:
708 /// f(in0, ..., inN, out0, ..., outN)
709 Function *CodeExtractor::constructFunction(const ValueSet &inputs,
710  const ValueSet &outputs,
711  BasicBlock *header,
712  BasicBlock *newRootNode,
713  BasicBlock *newHeader,
714  Function *oldFunction,
715  Module *M) {
716  LLVM_DEBUG(dbgs() << "inputs: " << inputs.size() << "\n");
717  LLVM_DEBUG(dbgs() << "outputs: " << outputs.size() << "\n");
718 
719  // This function returns unsigned, outputs will go back by reference.
720  switch (NumExitBlocks) {
721  case 0:
722  case 1: RetTy = Type::getVoidTy(header->getContext()); break;
723  case 2: RetTy = Type::getInt1Ty(header->getContext()); break;
724  default: RetTy = Type::getInt16Ty(header->getContext()); break;
725  }
726 
727  std::vector<Type *> paramTy;
728 
729  // Add the types of the input values to the function's argument list
730  for (Value *value : inputs) {
731  LLVM_DEBUG(dbgs() << "value used in func: " << *value << "\n");
732  paramTy.push_back(value->getType());
733  }
734 
735  // Add the types of the output values to the function's argument list.
736  for (Value *output : outputs) {
737  LLVM_DEBUG(dbgs() << "instr used in func: " << *output << "\n");
738  if (AggregateArgs)
739  paramTy.push_back(output->getType());
740  else
741  paramTy.push_back(PointerType::getUnqual(output->getType()));
742  }
743 
744  LLVM_DEBUG({
745  dbgs() << "Function type: " << *RetTy << " f(";
746  for (Type *i : paramTy)
747  dbgs() << *i << ", ";
748  dbgs() << ")\n";
749  });
750 
751  StructType *StructTy;
752  if (AggregateArgs && (inputs.size() + outputs.size() > 0)) {
753  StructTy = StructType::get(M->getContext(), paramTy);
754  paramTy.clear();
755  paramTy.push_back(PointerType::getUnqual(StructTy));
756  }
757  FunctionType *funcType =
758  FunctionType::get(RetTy, paramTy,
759  AllowVarArgs && oldFunction->isVarArg());
760 
761  std::string SuffixToUse =
762  Suffix.empty()
763  ? (header->getName().empty() ? "extracted" : header->getName().str())
764  : Suffix;
765  // Create the new function
766  Function *newFunction = Function::Create(
767  funcType, GlobalValue::InternalLinkage, oldFunction->getAddressSpace(),
768  oldFunction->getName() + "." + SuffixToUse, M);
769  // If the old function is no-throw, so is the new one.
770  if (oldFunction->doesNotThrow())
771  newFunction->setDoesNotThrow();
772 
773  // Inherit the uwtable attribute if we need to.
774  if (oldFunction->hasUWTable())
775  newFunction->setHasUWTable();
776 
777  // Inherit all of the target dependent attributes and white-listed
778  // target independent attributes.
779  // (e.g. If the extracted region contains a call to an x86.sse
780  // instruction we need to make sure that the extracted region has the
781  // "target-features" attribute allowing it to be lowered.
782  // FIXME: This should be changed to check to see if a specific
783  // attribute can not be inherited.
784  for (const auto &Attr : oldFunction->getAttributes().getFnAttributes()) {
785  if (Attr.isStringAttribute()) {
786  if (Attr.getKindAsString() == "thunk")
787  continue;
788  } else
789  switch (Attr.getKindAsEnum()) {
790  // Those attributes cannot be propagated safely. Explicitly list them
791  // here so we get a warning if new attributes are added. This list also
792  // includes non-function attributes.
793  case Attribute::Alignment:
794  case Attribute::AllocSize:
795  case Attribute::ArgMemOnly:
796  case Attribute::Builtin:
797  case Attribute::ByVal:
799  case Attribute::Dereferenceable:
800  case Attribute::DereferenceableOrNull:
801  case Attribute::InAlloca:
802  case Attribute::InReg:
803  case Attribute::InaccessibleMemOnly:
804  case Attribute::InaccessibleMemOrArgMemOnly:
806  case Attribute::Naked:
807  case Attribute::Nest:
808  case Attribute::NoAlias:
809  case Attribute::NoBuiltin:
810  case Attribute::NoCapture:
811  case Attribute::NoReturn:
812  case Attribute::NoSync:
813  case Attribute::None:
814  case Attribute::NonNull:
815  case Attribute::ReadNone:
816  case Attribute::ReadOnly:
817  case Attribute::Returned:
818  case Attribute::ReturnsTwice:
819  case Attribute::SExt:
820  case Attribute::Speculatable:
821  case Attribute::StackAlignment:
822  case Attribute::StructRet:
823  case Attribute::SwiftError:
824  case Attribute::SwiftSelf:
825  case Attribute::WillReturn:
826  case Attribute::WriteOnly:
827  case Attribute::ZExt:
828  case Attribute::ImmArg:
830  continue;
831  // Those attributes should be safe to propagate to the extracted function.
832  case Attribute::AlwaysInline:
833  case Attribute::Cold:
834  case Attribute::NoRecurse:
835  case Attribute::InlineHint:
836  case Attribute::MinSize:
837  case Attribute::NoDuplicate:
838  case Attribute::NoFree:
839  case Attribute::NoImplicitFloat:
840  case Attribute::NoInline:
841  case Attribute::NonLazyBind:
842  case Attribute::NoRedZone:
843  case Attribute::NoUnwind:
844  case Attribute::OptForFuzzing:
845  case Attribute::OptimizeNone:
846  case Attribute::OptimizeForSize:
847  case Attribute::SafeStack:
848  case Attribute::ShadowCallStack:
849  case Attribute::SanitizeAddress:
850  case Attribute::SanitizeMemory:
851  case Attribute::SanitizeThread:
852  case Attribute::SanitizeHWAddress:
853  case Attribute::SanitizeMemTag:
854  case Attribute::SpeculativeLoadHardening:
855  case Attribute::StackProtect:
856  case Attribute::StackProtectReq:
857  case Attribute::StackProtectStrong:
858  case Attribute::StrictFP:
859  case Attribute::UWTable:
860  case Attribute::NoCfCheck:
861  break;
862  }
863 
864  newFunction->addFnAttr(Attr);
865  }
866  newFunction->getBasicBlockList().push_back(newRootNode);
867 
868  // Create an iterator to name all of the arguments we inserted.
869  Function::arg_iterator AI = newFunction->arg_begin();
870 
871  // Rewrite all users of the inputs in the extracted region to use the
872  // arguments (or appropriate addressing into struct) instead.
873  for (unsigned i = 0, e = inputs.size(); i != e; ++i) {
874  Value *RewriteVal;
875  if (AggregateArgs) {
876  Value *Idx[2];
878  Idx[1] = ConstantInt::get(Type::getInt32Ty(header->getContext()), i);
879  Instruction *TI = newFunction->begin()->getTerminator();
881  StructTy, &*AI, Idx, "gep_" + inputs[i]->getName(), TI);
882  RewriteVal = new LoadInst(StructTy->getElementType(i), GEP,
883  "loadgep_" + inputs[i]->getName(), TI);
884  } else
885  RewriteVal = &*AI++;
886 
887  std::vector<User *> Users(inputs[i]->user_begin(), inputs[i]->user_end());
888  for (User *use : Users)
889  if (Instruction *inst = dyn_cast<Instruction>(use))
890  if (Blocks.count(inst->getParent()))
891  inst->replaceUsesOfWith(inputs[i], RewriteVal);
892  }
893 
894  // Set names for input and output arguments.
895  if (!AggregateArgs) {
896  AI = newFunction->arg_begin();
897  for (unsigned i = 0, e = inputs.size(); i != e; ++i, ++AI)
898  AI->setName(inputs[i]->getName());
899  for (unsigned i = 0, e = outputs.size(); i != e; ++i, ++AI)
900  AI->setName(outputs[i]->getName()+".out");
901  }
902 
903  // Rewrite branches to basic blocks outside of the loop to new dummy blocks
904  // within the new function. This must be done before we lose track of which
905  // blocks were originally in the code region.
906  std::vector<User *> Users(header->user_begin(), header->user_end());
907  for (unsigned i = 0, e = Users.size(); i != e; ++i)
908  // The BasicBlock which contains the branch is not in the region
909  // modify the branch target to a new block
910  if (Instruction *I = dyn_cast<Instruction>(Users[i]))
911  if (I->isTerminator() && !Blocks.count(I->getParent()) &&
912  I->getParent()->getParent() == oldFunction)
913  I->replaceUsesOfWith(header, newHeader);
914 
915  return newFunction;
916 }
917 
918 /// Erase lifetime.start markers which reference inputs to the extraction
919 /// region, and insert the referenced memory into \p LifetimesStart.
920 ///
921 /// The extraction region is defined by a set of blocks (\p Blocks), and a set
922 /// of allocas which will be moved from the caller function into the extracted
923 /// function (\p SunkAllocas).
925  const SetVector<Value *> &SunkAllocas,
926  SetVector<Value *> &LifetimesStart) {
927  for (BasicBlock *BB : Blocks) {
928  for (auto It = BB->begin(), End = BB->end(); It != End;) {
929  auto *II = dyn_cast<IntrinsicInst>(&*It);
930  ++It;
931  if (!II || !II->isLifetimeStartOrEnd())
932  continue;
933 
934  // Get the memory operand of the lifetime marker. If the underlying
935  // object is a sunk alloca, or is otherwise defined in the extraction
936  // region, the lifetime marker must not be erased.
937  Value *Mem = II->getOperand(1)->stripInBoundsOffsets();
938  if (SunkAllocas.count(Mem) || definedInRegion(Blocks, Mem))
939  continue;
940 
941  if (II->getIntrinsicID() == Intrinsic::lifetime_start)
942  LifetimesStart.insert(Mem);
943  II->eraseFromParent();
944  }
945  }
946 }
947 
948 /// Insert lifetime start/end markers surrounding the call to the new function
949 /// for objects defined in the caller.
951  Module *M, ArrayRef<Value *> LifetimesStart, ArrayRef<Value *> LifetimesEnd,
952  CallInst *TheCall) {
953  LLVMContext &Ctx = M->getContext();
954  auto Int8PtrTy = Type::getInt8PtrTy(Ctx);
955  auto NegativeOne = ConstantInt::getSigned(Type::getInt64Ty(Ctx), -1);
956  Instruction *Term = TheCall->getParent()->getTerminator();
957 
958  // The memory argument to a lifetime marker must be a i8*. Cache any bitcasts
959  // needed to satisfy this requirement so they may be reused.
961 
962  // Emit lifetime markers for the pointers given in \p Objects. Insert the
963  // markers before the call if \p InsertBefore, and after the call otherwise.
964  auto insertMarkers = [&](Function *MarkerFunc, ArrayRef<Value *> Objects,
965  bool InsertBefore) {
966  for (Value *Mem : Objects) {
967  assert((!isa<Instruction>(Mem) || cast<Instruction>(Mem)->getFunction() ==
968  TheCall->getFunction()) &&
969  "Input memory not defined in original function");
970  Value *&MemAsI8Ptr = Bitcasts[Mem];
971  if (!MemAsI8Ptr) {
972  if (Mem->getType() == Int8PtrTy)
973  MemAsI8Ptr = Mem;
974  else
975  MemAsI8Ptr =
976  CastInst::CreatePointerCast(Mem, Int8PtrTy, "lt.cast", TheCall);
977  }
978 
979  auto Marker = CallInst::Create(MarkerFunc, {NegativeOne, MemAsI8Ptr});
980  if (InsertBefore)
981  Marker->insertBefore(TheCall);
982  else
983  Marker->insertBefore(Term);
984  }
985  };
986 
987  if (!LifetimesStart.empty()) {
988  auto StartFn = llvm::Intrinsic::getDeclaration(
989  M, llvm::Intrinsic::lifetime_start, Int8PtrTy);
990  insertMarkers(StartFn, LifetimesStart, /*InsertBefore=*/true);
991  }
992 
993  if (!LifetimesEnd.empty()) {
994  auto EndFn = llvm::Intrinsic::getDeclaration(
995  M, llvm::Intrinsic::lifetime_end, Int8PtrTy);
996  insertMarkers(EndFn, LifetimesEnd, /*InsertBefore=*/false);
997  }
998 }
999 
1000 /// emitCallAndSwitchStatement - This method sets up the caller side by adding
1001 /// the call instruction, splitting any PHI nodes in the header block as
1002 /// necessary.
1003 CallInst *CodeExtractor::emitCallAndSwitchStatement(Function *newFunction,
1004  BasicBlock *codeReplacer,
1005  ValueSet &inputs,
1006  ValueSet &outputs) {
1007  // Emit a call to the new function, passing in: *pointer to struct (if
1008  // aggregating parameters), or plan inputs and allocated memory for outputs
1009  std::vector<Value *> params, StructValues, ReloadOutputs, Reloads;
1010 
1011  Module *M = newFunction->getParent();
1012  LLVMContext &Context = M->getContext();
1013  const DataLayout &DL = M->getDataLayout();
1014  CallInst *call = nullptr;
1015 
1016  // Add inputs as params, or to be filled into the struct
1017  unsigned ArgNo = 0;
1018  SmallVector<unsigned, 1> SwiftErrorArgs;
1019  for (Value *input : inputs) {
1020  if (AggregateArgs)
1021  StructValues.push_back(input);
1022  else {
1023  params.push_back(input);
1024  if (input->isSwiftError())
1025  SwiftErrorArgs.push_back(ArgNo);
1026  }
1027  ++ArgNo;
1028  }
1029 
1030  // Create allocas for the outputs
1031  for (Value *output : outputs) {
1032  if (AggregateArgs) {
1033  StructValues.push_back(output);
1034  } else {
1035  AllocaInst *alloca =
1036  new AllocaInst(output->getType(), DL.getAllocaAddrSpace(),
1037  nullptr, output->getName() + ".loc",
1038  &codeReplacer->getParent()->front().front());
1039  ReloadOutputs.push_back(alloca);
1040  params.push_back(alloca);
1041  }
1042  }
1043 
1044  StructType *StructArgTy = nullptr;
1045  AllocaInst *Struct = nullptr;
1046  if (AggregateArgs && (inputs.size() + outputs.size() > 0)) {
1047  std::vector<Type *> ArgTypes;
1048  for (ValueSet::iterator v = StructValues.begin(),
1049  ve = StructValues.end(); v != ve; ++v)
1050  ArgTypes.push_back((*v)->getType());
1051 
1052  // Allocate a struct at the beginning of this function
1053  StructArgTy = StructType::get(newFunction->getContext(), ArgTypes);
1054  Struct = new AllocaInst(StructArgTy, DL.getAllocaAddrSpace(), nullptr,
1055  "structArg",
1056  &codeReplacer->getParent()->front().front());
1057  params.push_back(Struct);
1058 
1059  for (unsigned i = 0, e = inputs.size(); i != e; ++i) {
1060  Value *Idx[2];
1061  Idx[0] = Constant::getNullValue(Type::getInt32Ty(Context));
1062  Idx[1] = ConstantInt::get(Type::getInt32Ty(Context), i);
1064  StructArgTy, Struct, Idx, "gep_" + StructValues[i]->getName());
1065  codeReplacer->getInstList().push_back(GEP);
1066  StoreInst *SI = new StoreInst(StructValues[i], GEP);
1067  codeReplacer->getInstList().push_back(SI);
1068  }
1069  }
1070 
1071  // Emit the call to the function
1072  call = CallInst::Create(newFunction, params,
1073  NumExitBlocks > 1 ? "targetBlock" : "");
1074  // Add debug location to the new call, if the original function has debug
1075  // info. In that case, the terminator of the entry block of the extracted
1076  // function contains the first debug location of the extracted function,
1077  // set in extractCodeRegion.
1078  if (codeReplacer->getParent()->getSubprogram()) {
1079  if (auto DL = newFunction->getEntryBlock().getTerminator()->getDebugLoc())
1080  call->setDebugLoc(DL);
1081  }
1082  codeReplacer->getInstList().push_back(call);
1083 
1084  // Set swifterror parameter attributes.
1085  for (unsigned SwiftErrArgNo : SwiftErrorArgs) {
1086  call->addParamAttr(SwiftErrArgNo, Attribute::SwiftError);
1087  newFunction->addParamAttr(SwiftErrArgNo, Attribute::SwiftError);
1088  }
1089 
1090  Function::arg_iterator OutputArgBegin = newFunction->arg_begin();
1091  unsigned FirstOut = inputs.size();
1092  if (!AggregateArgs)
1093  std::advance(OutputArgBegin, inputs.size());
1094 
1095  // Reload the outputs passed in by reference.
1096  for (unsigned i = 0, e = outputs.size(); i != e; ++i) {
1097  Value *Output = nullptr;
1098  if (AggregateArgs) {
1099  Value *Idx[2];
1100  Idx[0] = Constant::getNullValue(Type::getInt32Ty(Context));
1101  Idx[1] = ConstantInt::get(Type::getInt32Ty(Context), FirstOut + i);
1103  StructArgTy, Struct, Idx, "gep_reload_" + outputs[i]->getName());
1104  codeReplacer->getInstList().push_back(GEP);
1105  Output = GEP;
1106  } else {
1107  Output = ReloadOutputs[i];
1108  }
1109  LoadInst *load = new LoadInst(outputs[i]->getType(), Output,
1110  outputs[i]->getName() + ".reload");
1111  Reloads.push_back(load);
1112  codeReplacer->getInstList().push_back(load);
1113  std::vector<User *> Users(outputs[i]->user_begin(), outputs[i]->user_end());
1114  for (unsigned u = 0, e = Users.size(); u != e; ++u) {
1115  Instruction *inst = cast<Instruction>(Users[u]);
1116  if (!Blocks.count(inst->getParent()))
1117  inst->replaceUsesOfWith(outputs[i], load);
1118  }
1119  }
1120 
1121  // Now we can emit a switch statement using the call as a value.
1122  SwitchInst *TheSwitch =
1124  codeReplacer, 0, codeReplacer);
1125 
1126  // Since there may be multiple exits from the original region, make the new
1127  // function return an unsigned, switch on that number. This loop iterates
1128  // over all of the blocks in the extracted region, updating any terminator
1129  // instructions in the to-be-extracted region that branch to blocks that are
1130  // not in the region to be extracted.
1131  std::map<BasicBlock *, BasicBlock *> ExitBlockMap;
1132 
1133  unsigned switchVal = 0;
1134  for (BasicBlock *Block : Blocks) {
1135  Instruction *TI = Block->getTerminator();
1136  for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
1137  if (!Blocks.count(TI->getSuccessor(i))) {
1138  BasicBlock *OldTarget = TI->getSuccessor(i);
1139  // add a new basic block which returns the appropriate value
1140  BasicBlock *&NewTarget = ExitBlockMap[OldTarget];
1141  if (!NewTarget) {
1142  // If we don't already have an exit stub for this non-extracted
1143  // destination, create one now!
1144  NewTarget = BasicBlock::Create(Context,
1145  OldTarget->getName() + ".exitStub",
1146  newFunction);
1147  unsigned SuccNum = switchVal++;
1148 
1149  Value *brVal = nullptr;
1150  switch (NumExitBlocks) {
1151  case 0:
1152  case 1: break; // No value needed.
1153  case 2: // Conditional branch, return a bool
1154  brVal = ConstantInt::get(Type::getInt1Ty(Context), !SuccNum);
1155  break;
1156  default:
1157  brVal = ConstantInt::get(Type::getInt16Ty(Context), SuccNum);
1158  break;
1159  }
1160 
1161  ReturnInst::Create(Context, brVal, NewTarget);
1162 
1163  // Update the switch instruction.
1164  TheSwitch->addCase(ConstantInt::get(Type::getInt16Ty(Context),
1165  SuccNum),
1166  OldTarget);
1167  }
1168 
1169  // rewrite the original branch instruction with this new target
1170  TI->setSuccessor(i, NewTarget);
1171  }
1172  }
1173 
1174  // Store the arguments right after the definition of output value.
1175  // This should be proceeded after creating exit stubs to be ensure that invoke
1176  // result restore will be placed in the outlined function.
1177  Function::arg_iterator OAI = OutputArgBegin;
1178  for (unsigned i = 0, e = outputs.size(); i != e; ++i) {
1179  auto *OutI = dyn_cast<Instruction>(outputs[i]);
1180  if (!OutI)
1181  continue;
1182 
1183  // Find proper insertion point.
1184  BasicBlock::iterator InsertPt;
1185  // In case OutI is an invoke, we insert the store at the beginning in the
1186  // 'normal destination' BB. Otherwise we insert the store right after OutI.
1187  if (auto *InvokeI = dyn_cast<InvokeInst>(OutI))
1188  InsertPt = InvokeI->getNormalDest()->getFirstInsertionPt();
1189  else if (auto *Phi = dyn_cast<PHINode>(OutI))
1190  InsertPt = Phi->getParent()->getFirstInsertionPt();
1191  else
1192  InsertPt = std::next(OutI->getIterator());
1193 
1194  Instruction *InsertBefore = &*InsertPt;
1195  assert((InsertBefore->getFunction() == newFunction ||
1196  Blocks.count(InsertBefore->getParent())) &&
1197  "InsertPt should be in new function");
1198  assert(OAI != newFunction->arg_end() &&
1199  "Number of output arguments should match "
1200  "the amount of defined values");
1201  if (AggregateArgs) {
1202  Value *Idx[2];
1203  Idx[0] = Constant::getNullValue(Type::getInt32Ty(Context));
1204  Idx[1] = ConstantInt::get(Type::getInt32Ty(Context), FirstOut + i);
1206  StructArgTy, &*OAI, Idx, "gep_" + outputs[i]->getName(),
1207  InsertBefore);
1208  new StoreInst(outputs[i], GEP, InsertBefore);
1209  // Since there should be only one struct argument aggregating
1210  // all the output values, we shouldn't increment OAI, which always
1211  // points to the struct argument, in this case.
1212  } else {
1213  new StoreInst(outputs[i], &*OAI, InsertBefore);
1214  ++OAI;
1215  }
1216  }
1217 
1218  // Now that we've done the deed, simplify the switch instruction.
1219  Type *OldFnRetTy = TheSwitch->getParent()->getParent()->getReturnType();
1220  switch (NumExitBlocks) {
1221  case 0:
1222  // There are no successors (the block containing the switch itself), which
1223  // means that previously this was the last part of the function, and hence
1224  // this should be rewritten as a `ret'
1225 
1226  // Check if the function should return a value
1227  if (OldFnRetTy->isVoidTy()) {
1228  ReturnInst::Create(Context, nullptr, TheSwitch); // Return void
1229  } else if (OldFnRetTy == TheSwitch->getCondition()->getType()) {
1230  // return what we have
1231  ReturnInst::Create(Context, TheSwitch->getCondition(), TheSwitch);
1232  } else {
1233  // Otherwise we must have code extracted an unwind or something, just
1234  // return whatever we want.
1235  ReturnInst::Create(Context,
1236  Constant::getNullValue(OldFnRetTy), TheSwitch);
1237  }
1238 
1239  TheSwitch->eraseFromParent();
1240  break;
1241  case 1:
1242  // Only a single destination, change the switch into an unconditional
1243  // branch.
1244  BranchInst::Create(TheSwitch->getSuccessor(1), TheSwitch);
1245  TheSwitch->eraseFromParent();
1246  break;
1247  case 2:
1248  BranchInst::Create(TheSwitch->getSuccessor(1), TheSwitch->getSuccessor(2),
1249  call, TheSwitch);
1250  TheSwitch->eraseFromParent();
1251  break;
1252  default:
1253  // Otherwise, make the default destination of the switch instruction be one
1254  // of the other successors.
1255  TheSwitch->setCondition(call);
1256  TheSwitch->setDefaultDest(TheSwitch->getSuccessor(NumExitBlocks));
1257  // Remove redundant case
1258  TheSwitch->removeCase(SwitchInst::CaseIt(TheSwitch, NumExitBlocks-1));
1259  break;
1260  }
1261 
1262  // Insert lifetime markers around the reloads of any output values. The
1263  // allocas output values are stored in are only in-use in the codeRepl block.
1264  insertLifetimeMarkersSurroundingCall(M, ReloadOutputs, ReloadOutputs, call);
1265 
1266  return call;
1267 }
1268 
1269 void CodeExtractor::moveCodeToFunction(Function *newFunction) {
1270  Function *oldFunc = (*Blocks.begin())->getParent();
1271  Function::BasicBlockListType &oldBlocks = oldFunc->getBasicBlockList();
1272  Function::BasicBlockListType &newBlocks = newFunction->getBasicBlockList();
1273 
1274  for (BasicBlock *Block : Blocks) {
1275  // Delete the basic block from the old function, and the list of blocks
1276  oldBlocks.remove(Block);
1277 
1278  // Insert this basic block into the new function
1279  newBlocks.push_back(Block);
1280 
1281  // Remove @llvm.assume calls that were moved to the new function from the
1282  // old function's assumption cache.
1283  if (AC)
1284  for (auto &I : *Block)
1285  if (match(&I, m_Intrinsic<Intrinsic::assume>()))
1286  AC->unregisterAssumption(cast<CallInst>(&I));
1287  }
1288 }
1289 
1290 void CodeExtractor::calculateNewCallTerminatorWeights(
1291  BasicBlock *CodeReplacer,
1293  BranchProbabilityInfo *BPI) {
1294  using Distribution = BlockFrequencyInfoImplBase::Distribution;
1295  using BlockNode = BlockFrequencyInfoImplBase::BlockNode;
1296 
1297  // Update the branch weights for the exit block.
1298  Instruction *TI = CodeReplacer->getTerminator();
1299  SmallVector<unsigned, 8> BranchWeights(TI->getNumSuccessors(), 0);
1300 
1301  // Block Frequency distribution with dummy node.
1302  Distribution BranchDist;
1303 
1304  // Add each of the frequencies of the successors.
1305  for (unsigned i = 0, e = TI->getNumSuccessors(); i < e; ++i) {
1306  BlockNode ExitNode(i);
1307  uint64_t ExitFreq = ExitWeights[TI->getSuccessor(i)].getFrequency();
1308  if (ExitFreq != 0)
1309  BranchDist.addExit(ExitNode, ExitFreq);
1310  else
1311  BPI->setEdgeProbability(CodeReplacer, i, BranchProbability::getZero());
1312  }
1313 
1314  // Check for no total weight.
1315  if (BranchDist.Total == 0)
1316  return;
1317 
1318  // Normalize the distribution so that they can fit in unsigned.
1319  BranchDist.normalize();
1320 
1321  // Create normalized branch weights and set the metadata.
1322  for (unsigned I = 0, E = BranchDist.Weights.size(); I < E; ++I) {
1323  const auto &Weight = BranchDist.Weights[I];
1324 
1325  // Get the weight and update the current BFI.
1326  BranchWeights[Weight.TargetNode.Index] = Weight.Amount;
1327  BranchProbability BP(Weight.Amount, BranchDist.Total);
1328  BPI->setEdgeProbability(CodeReplacer, Weight.TargetNode.Index, BP);
1329  }
1330  TI->setMetadata(
1332  MDBuilder(TI->getContext()).createBranchWeights(BranchWeights));
1333 }
1334 
1336  if (!isEligible())
1337  return nullptr;
1338 
1339  // Assumption: this is a single-entry code region, and the header is the first
1340  // block in the region.
1341  BasicBlock *header = *Blocks.begin();
1342  Function *oldFunction = header->getParent();
1343 
1344  // For functions with varargs, check that varargs handling is only done in the
1345  // outlined function, i.e vastart and vaend are only used in outlined blocks.
1346  if (AllowVarArgs && oldFunction->getFunctionType()->isVarArg()) {
1347  auto containsVarArgIntrinsic = [](Instruction &I) {
1348  if (const CallInst *CI = dyn_cast<CallInst>(&I))
1349  if (const Function *F = CI->getCalledFunction())
1350  return F->getIntrinsicID() == Intrinsic::vastart ||
1351  F->getIntrinsicID() == Intrinsic::vaend;
1352  return false;
1353  };
1354 
1355  for (auto &BB : *oldFunction) {
1356  if (Blocks.count(&BB))
1357  continue;
1358  if (llvm::any_of(BB, containsVarArgIntrinsic))
1359  return nullptr;
1360  }
1361  }
1362  ValueSet inputs, outputs, SinkingCands, HoistingCands;
1363  BasicBlock *CommonExit = nullptr;
1364 
1365  // Calculate the entry frequency of the new function before we change the root
1366  // block.
1367  BlockFrequency EntryFreq;
1368  if (BFI) {
1369  assert(BPI && "Both BPI and BFI are required to preserve profile info");
1370  for (BasicBlock *Pred : predecessors(header)) {
1371  if (Blocks.count(Pred))
1372  continue;
1373  EntryFreq +=
1374  BFI->getBlockFreq(Pred) * BPI->getEdgeProbability(Pred, header);
1375  }
1376  }
1377 
1378  // If we have any return instructions in the region, split those blocks so
1379  // that the return is not in the region.
1380  splitReturnBlocks();
1381 
1382  // Calculate the exit blocks for the extracted region and the total exit
1383  // weights for each of those blocks.
1385  SmallPtrSet<BasicBlock *, 1> ExitBlocks;
1386  for (BasicBlock *Block : Blocks) {
1387  for (succ_iterator SI = succ_begin(Block), SE = succ_end(Block); SI != SE;
1388  ++SI) {
1389  if (!Blocks.count(*SI)) {
1390  // Update the branch weight for this successor.
1391  if (BFI) {
1392  BlockFrequency &BF = ExitWeights[*SI];
1393  BF += BFI->getBlockFreq(Block) * BPI->getEdgeProbability(Block, *SI);
1394  }
1395  ExitBlocks.insert(*SI);
1396  }
1397  }
1398  }
1399  NumExitBlocks = ExitBlocks.size();
1400 
1401  // If we have to split PHI nodes of the entry or exit blocks, do so now.
1402  severSplitPHINodesOfEntry(header);
1403  severSplitPHINodesOfExits(ExitBlocks);
1404 
1405  // This takes place of the original loop
1406  BasicBlock *codeReplacer = BasicBlock::Create(header->getContext(),
1407  "codeRepl", oldFunction,
1408  header);
1409 
1410  // The new function needs a root node because other nodes can branch to the
1411  // head of the region, but the entry node of a function cannot have preds.
1412  BasicBlock *newFuncRoot = BasicBlock::Create(header->getContext(),
1413  "newFuncRoot");
1414  auto *BranchI = BranchInst::Create(header);
1415  // If the original function has debug info, we have to add a debug location
1416  // to the new branch instruction from the artificial entry block.
1417  // We use the debug location of the first instruction in the extracted
1418  // blocks, as there is no other equivalent line in the source code.
1419  if (oldFunction->getSubprogram()) {
1420  any_of(Blocks, [&BranchI](const BasicBlock *BB) {
1421  return any_of(*BB, [&BranchI](const Instruction &I) {
1422  if (!I.getDebugLoc())
1423  return false;
1424  BranchI->setDebugLoc(I.getDebugLoc());
1425  return true;
1426  });
1427  });
1428  }
1429  newFuncRoot->getInstList().push_back(BranchI);
1430 
1431  findAllocas(SinkingCands, HoistingCands, CommonExit);
1432  assert(HoistingCands.empty() || CommonExit);
1433 
1434  // Find inputs to, outputs from the code region.
1435  findInputsOutputs(inputs, outputs, SinkingCands);
1436 
1437  // Now sink all instructions which only have non-phi uses inside the region.
1438  // Group the allocas at the start of the block, so that any bitcast uses of
1439  // the allocas are well-defined.
1440  AllocaInst *FirstSunkAlloca = nullptr;
1441  for (auto *II : SinkingCands) {
1442  if (auto *AI = dyn_cast<AllocaInst>(II)) {
1443  AI->moveBefore(*newFuncRoot, newFuncRoot->getFirstInsertionPt());
1444  if (!FirstSunkAlloca)
1445  FirstSunkAlloca = AI;
1446  }
1447  }
1448  assert((SinkingCands.empty() || FirstSunkAlloca) &&
1449  "Did not expect a sink candidate without any allocas");
1450  for (auto *II : SinkingCands) {
1451  if (!isa<AllocaInst>(II)) {
1452  cast<Instruction>(II)->moveAfter(FirstSunkAlloca);
1453  }
1454  }
1455 
1456  if (!HoistingCands.empty()) {
1457  auto *HoistToBlock = findOrCreateBlockForHoisting(CommonExit);
1458  Instruction *TI = HoistToBlock->getTerminator();
1459  for (auto *II : HoistingCands)
1460  cast<Instruction>(II)->moveBefore(TI);
1461  }
1462 
1463  // Collect objects which are inputs to the extraction region and also
1464  // referenced by lifetime start markers within it. The effects of these
1465  // markers must be replicated in the calling function to prevent the stack
1466  // coloring pass from merging slots which store input objects.
1467  ValueSet LifetimesStart;
1468  eraseLifetimeMarkersOnInputs(Blocks, SinkingCands, LifetimesStart);
1469 
1470  // Construct new function based on inputs/outputs & add allocas for all defs.
1471  Function *newFunction =
1472  constructFunction(inputs, outputs, header, newFuncRoot, codeReplacer,
1473  oldFunction, oldFunction->getParent());
1474 
1475  // Update the entry count of the function.
1476  if (BFI) {
1477  auto Count = BFI->getProfileCountFromFreq(EntryFreq.getFrequency());
1478  if (Count.hasValue())
1479  newFunction->setEntryCount(
1480  ProfileCount(Count.getValue(), Function::PCT_Real)); // FIXME
1481  BFI->setBlockFreq(codeReplacer, EntryFreq.getFrequency());
1482  }
1483 
1484  CallInst *TheCall =
1485  emitCallAndSwitchStatement(newFunction, codeReplacer, inputs, outputs);
1486 
1487  moveCodeToFunction(newFunction);
1488 
1489  // Replicate the effects of any lifetime start/end markers which referenced
1490  // input objects in the extraction region by placing markers around the call.
1492  oldFunction->getParent(), LifetimesStart.getArrayRef(), {}, TheCall);
1493 
1494  // Propagate personality info to the new function if there is one.
1495  if (oldFunction->hasPersonalityFn())
1496  newFunction->setPersonalityFn(oldFunction->getPersonalityFn());
1497 
1498  // Update the branch weights for the exit block.
1499  if (BFI && NumExitBlocks > 1)
1500  calculateNewCallTerminatorWeights(codeReplacer, ExitWeights, BPI);
1501 
1502  // Loop over all of the PHI nodes in the header and exit blocks, and change
1503  // any references to the old incoming edge to be the new incoming edge.
1504  for (BasicBlock::iterator I = header->begin(); isa<PHINode>(I); ++I) {
1505  PHINode *PN = cast<PHINode>(I);
1506  for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
1507  if (!Blocks.count(PN->getIncomingBlock(i)))
1508  PN->setIncomingBlock(i, newFuncRoot);
1509  }
1510 
1511  for (BasicBlock *ExitBB : ExitBlocks)
1512  for (PHINode &PN : ExitBB->phis()) {
1513  Value *IncomingCodeReplacerVal = nullptr;
1514  for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1515  // Ignore incoming values from outside of the extracted region.
1516  if (!Blocks.count(PN.getIncomingBlock(i)))
1517  continue;
1518 
1519  // Ensure that there is only one incoming value from codeReplacer.
1520  if (!IncomingCodeReplacerVal) {
1521  PN.setIncomingBlock(i, codeReplacer);
1522  IncomingCodeReplacerVal = PN.getIncomingValue(i);
1523  } else
1524  assert(IncomingCodeReplacerVal == PN.getIncomingValue(i) &&
1525  "PHI has two incompatbile incoming values from codeRepl");
1526  }
1527  }
1528 
1529  // Erase debug info intrinsics. Variable updates within the new function are
1530  // invisible to debuggers. This could be improved by defining a DISubprogram
1531  // for the new function.
1532  for (BasicBlock &BB : *newFunction) {
1533  auto BlockIt = BB.begin();
1534  // Remove debug info intrinsics from the new function.
1535  while (BlockIt != BB.end()) {
1536  Instruction *Inst = &*BlockIt;
1537  ++BlockIt;
1538  if (isa<DbgInfoIntrinsic>(Inst))
1539  Inst->eraseFromParent();
1540  }
1541  // Remove debug info intrinsics which refer to values in the new function
1542  // from the old function.
1544  for (Instruction &I : BB)
1545  findDbgUsers(DbgUsers, &I);
1546  for (DbgVariableIntrinsic *DVI : DbgUsers)
1547  DVI->eraseFromParent();
1548  }
1549 
1550  // Mark the new function `noreturn` if applicable. Terminators which resume
1551  // exception propagation are treated as returning instructions. This is to
1552  // avoid inserting traps after calls to outlined functions which unwind.
1553  bool doesNotReturn = none_of(*newFunction, [](const BasicBlock &BB) {
1554  const Instruction *Term = BB.getTerminator();
1555  return isa<ReturnInst>(Term) || isa<ResumeInst>(Term);
1556  });
1557  if (doesNotReturn)
1558  newFunction->setDoesNotReturn();
1559 
1560  LLVM_DEBUG(if (verifyFunction(*newFunction, &errs())) {
1561  newFunction->dump();
1562  report_fatal_error("verification of newFunction failed!");
1563  });
1564  LLVM_DEBUG(if (verifyFunction(*oldFunction))
1565  report_fatal_error("verification of oldFunction failed!"));
1566  return newFunction;
1567 }
bool isVarArg() const
isVarArg - Return true if this function takes a variable number of arguments.
Definition: Function.h:176
static BasicBlock * getCommonExitBlock(const SetVector< BasicBlock *> &Blocks)
Return a value (possibly void), from a function.
SymbolTableList< Instruction >::iterator eraseFromParent()
This method unlinks &#39;this&#39; from the containing basic block and deletes it.
Definition: Instruction.cpp:67
A parsed version of the target data layout string in and methods for querying it. ...
Definition: DataLayout.h:110
raw_ostream & errs()
This returns a reference to a raw_ostream for standard error.
static IntegerType * getInt1Ty(LLVMContext &C)
Definition: Type.cpp:172
void addIncoming(Value *V, BasicBlock *BB)
Add an incoming value to the end of the PHI list.
This class represents an incoming formal argument to a Function.
Definition: Argument.h:29
LLVM_NODISCARD std::string str() const
str - Get the contents as an std::string.
Definition: StringRef.h:218
LLVMContext & Context
const Value * stripInBoundsOffsets() const
Strip off pointer casts and inbounds GEPs.
Definition: Value.cpp:612
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:139
This class represents lattice values for constants.
Definition: AllocatorList.h:23
ArrayRef< T > getArrayRef() const
Definition: SetVector.h:63
size_type size() const
Determine the number of elements in the SetVector.
Definition: SetVector.h:77
void addParamAttr(unsigned ArgNo, Attribute::AttrKind Kind)
adds the attribute to the list of attributes for the given arg.
Definition: Function.cpp:398
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:65
void findInputsOutputs(ValueSet &Inputs, ValueSet &Outputs, const ValueSet &Allocas) const
Compute the set of input values and output values for the code.
BasicBlock * getSuccessor(unsigned Idx) const
Return the specified successor. This instruction must be a terminator.
static CallInst * Create(FunctionType *Ty, Value *F, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
static cl::opt< bool > AggregateArgsOpt("aggregate-extracted-args", cl::Hidden, cl::desc("Aggregate arguments to code-extracted functions"))
void addCase(ConstantInt *OnVal, BasicBlock *Dest)
Add an entry to the switch instruction.
static GetElementPtrInst * Create(Type *PointeeType, Value *Ptr, ArrayRef< Value *> IdxList, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
Definition: Instructions.h:901
void findDbgUsers(SmallVectorImpl< DbgVariableIntrinsic *> &DbgInsts, Value *V)
Finds the debug info intrinsics describing a value.
Definition: Local.cpp:1540
This class represents a function call, abstracting a target machine&#39;s calling convention.
Value * getCondition() const
The two locations do not alias at all.
Definition: AliasAnalysis.h:84
A cache of @llvm.assume calls within a function.
uint64_t getFrequency() const
Returns the frequency as a fixpoint number scaled by the entry frequency.
Function * extractCodeRegion()
Perform the extraction, returning the new function.
LLVMContext & getContext() const
All values hold a context through their type.
Definition: Value.cpp:732
arg_iterator arg_end()
Definition: Function.h:704
F(f)
An instruction for reading from memory.
Definition: Instructions.h:167
static IntegerType * getInt64Ty(LLVMContext &C)
Definition: Type.cpp:176
Hexagon Common GEP
const Instruction * getTerminator() const LLVM_READONLY
Returns the terminator instruction if the block is well formed or null if the block is not well forme...
Definition: BasicBlock.cpp:137
void setSuccessor(unsigned Idx, BasicBlock *BB)
Update the specified successor to point at the provided block.
iv Induction Variable Users
Definition: IVUsers.cpp:51
static IntegerType * getInt16Ty(LLVMContext &C)
Definition: Type.cpp:174
LLVMContext & getContext() const
Get the context in which this basic block lives.
Definition: BasicBlock.cpp:32
bool isReachableFromEntry(const Use &U) const
Provide an overload for a Use.
Definition: Dominators.cpp:299
static Constant * getNullValue(Type *Ty)
Constructor to create a &#39;0&#39; constant of arbitrary type.
Definition: Constants.cpp:274
A templated base class for SmallPtrSet which provides the typesafe interface that is common across al...
Definition: SmallPtrSet.h:343
iterator begin()
Instruction iterator methods.
Definition: BasicBlock.h:268
static void insertLifetimeMarkersSurroundingCall(Module *M, ArrayRef< Value *> LifetimesStart, ArrayRef< Value *> LifetimesEnd, CallInst *TheCall)
Insert lifetime start/end markers surrounding the call to the new function for objects defined in the...
void setDoesNotThrow()
Definition: Function.h:536
static ReturnInst * Create(LLVMContext &C, Value *retVal=nullptr, Instruction *InsertBefore=nullptr)
static bool isBlockValidForExtraction(const BasicBlock &BB, const SetVector< BasicBlock *> &Result, bool AllowVarArgs, bool AllowAlloca)
Test whether a block is valid for extraction.
bool match(Val *V, const Pattern &P)
Definition: PatternMatch.h:47
unsigned getAllocaAddrSpace() const
Definition: DataLayout.h:269
static void eraseLifetimeMarkersOnInputs(const SetVector< BasicBlock *> &Blocks, const SetVector< Value *> &SunkAllocas, SetVector< Value *> &LifetimesStart)
Erase lifetime.start markers which reference inputs to the extraction region, and insert the referenc...
Value * removeIncomingValue(unsigned Idx, bool DeletePHIIfEmpty=true)
Remove an incoming value.
const DataLayout & getDataLayout() const
Get the data layout for the module&#39;s target platform.
Definition: Module.cpp:369
void setEntryCount(ProfileCount Count, const DenseSet< GlobalValue::GUID > *Imports=nullptr)
Set the entry count for this function.
Definition: Function.cpp:1448
static bool definedInCaller(const SetVector< BasicBlock *> &Blocks, Value *V)
definedInCaller - Return true if the specified value is defined in the function being code extracted...
Class to represent struct types.
Definition: DerivedTypes.h:233
LLVMContext & getContext() const
Get the global data context.
Definition: Module.h:244
A Use represents the edge between a Value definition and its users.
Definition: Use.h:55
bool hasUWTable() const
True if the ABI mandates (or the user requested) that this function be in a unwind table...
Definition: Function.h:586
bool none_of(R &&Range, UnaryPredicate P)
Provide wrappers to std::none_of which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:1206
static StringRef getName(Value *V)
This file contains the simple types necessary to represent the attributes associated with functions a...
No attributes have been set.
Definition: Attributes.h:71
static SetVector< BasicBlock * > buildExtractionBlockSet(ArrayRef< BasicBlock *> BBs, DominatorTree *DT, bool AllowVarArgs, bool AllowAlloca)
Build a set of blocks to extract if the input blocks are viable.
void setName(const Twine &Name)
Change the name of the value.
Definition: Value.cpp:285
void unregisterAssumption(CallInst *CI)
Remove an @llvm.assume intrinsic from this function&#39;s cache if it has been added to the cache earlier...
LLVM_NODISCARD bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:126
static StructType * get(LLVMContext &Context, ArrayRef< Type *> Elements, bool isPacked=false)
This static method is the primary way to create a literal StructType.
Definition: Type.cpp:341
Interval::succ_iterator succ_begin(Interval *I)
succ_begin/succ_end - define methods so that Intervals may be used just like BasicBlocks can with the...
Definition: Interval.h:102
auto reverse(ContainerTy &&C, typename std::enable_if< has_rbegin< ContainerTy >::value >::type *=nullptr) -> decltype(make_range(C.rbegin(), C.rend()))
Definition: STLExtras.h:273
Class to represent function types.
Definition: DerivedTypes.h:103
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:244
bool insert(const value_type &X)
Insert a new element into the SetVector.
Definition: SetVector.h:141
This is the common base class for debug info intrinsics for variables.
Definition: IntrinsicInst.h:87
bool isVarArg() const
Definition: DerivedTypes.h:123
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:32
AttributeList getAttributes() const
Return the attribute list for this Function.
Definition: Function.h:223
An instruction for storing to memory.
Definition: Instructions.h:320
bool hasPersonalityFn() const
Check whether this function has a personality function.
Definition: Function.h:726
void replaceAllUsesWith(Value *V)
Change all uses of this to point to a new Value.
Definition: Value.cpp:429
BasicBlock * getSuccessor(unsigned idx) const
static Function * getFunction(Constant *C)
Definition: Evaluator.cpp:258
iterator begin()
Definition: Function.h:680
Concrete subclass of DominatorTreeBase that is used to compute a normal dominator tree...
Definition: Dominators.h:144
Function * getDeclaration(Module *M, ID id, ArrayRef< Type *> Tys=None)
Create or insert an LLVM Function declaration for an intrinsic, and return it.
Definition: Function.cpp:1043
unsigned getNumSuccessors() const
Return the number of successors that this instruction has.
Analysis containing CSE Info
Definition: CSEInfo.cpp:20
size_type count(const key_type &key) const
Count the number of elements of a given key in the SetVector.
Definition: SetVector.h:210
Interval::succ_iterator succ_end(Interval *I)
Definition: Interval.h:105
void replaceUsesOfWith(Value *From, Value *To)
Replace uses of one Value with another.
Definition: User.cpp:20
static bool definedInRegion(const SetVector< BasicBlock *> &Blocks, Value *V)
definedInRegion - Return true if the specified value is defined in the extracted region.
bool isVoidTy() const
Return true if this is &#39;void&#39;.
Definition: Type.h:140
const BasicBlock & getEntryBlock() const
Definition: Function.h:664
an instruction for type-safe pointer arithmetic to access elements of arrays and structs ...
Definition: Instructions.h:875
BlockFrequencyInfo pass uses BlockFrequencyInfoImpl implementation to estimate IR basic block frequen...
Type * getReturnType() const
Returns the type of the ret val.
Definition: Function.h:168
static Function * Create(FunctionType *Ty, LinkageTypes Linkage, unsigned AddrSpace, const Twine &N="", Module *M=nullptr)
Definition: Function.h:135
const Instruction * getFirstNonPHI() const
Returns a pointer to the first instruction in this block that is not a PHINode instruction.
Definition: BasicBlock.cpp:189
void setDebugLoc(DebugLoc Loc)
Set the debug location information for this instruction.
Definition: Instruction.h:318
Move duplicate certain instructions close to their use
Definition: Localizer.cpp:27
void insertBefore(Instruction *InsertPos)
Insert an unlinked instruction into a basic block immediately before the specified instruction...
Definition: Instruction.cpp:73
LLVM Basic Block Representation.
Definition: BasicBlock.h:57
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
This is an important class for using LLVM in a threaded context.
Definition: LLVMContext.h:64
DISubprogram * getSubprogram() const
Get the attached subprogram.
Definition: Metadata.cpp:1504
void changeImmediateDominator(DomTreeNodeBase< NodeT > *N, DomTreeNodeBase< NodeT > *NewIDom)
changeImmediateDominator - This method is used to update the dominator tree information when a node&#39;s...
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
This file contains the declarations for the subclasses of Constant, which represent the different fla...
const Instruction & front() const
Definition: BasicBlock.h:280
Distribution of unscaled probability weight.
std::pair< iterator, bool > insert(PtrType Ptr)
Inserts Ptr if and only if there is no element in the container equal to Ptr.
Definition: SmallPtrSet.h:370
Interval::pred_iterator pred_begin(Interval *I)
pred_begin/pred_end - define methods so that Intervals may be used just like BasicBlocks can with the...
Definition: Interval.h:112
bool isLifetimeStartOrEnd() const
Return true if the instruction is a llvm.lifetime.start or llvm.lifetime.end marker.
static Type * getVoidTy(LLVMContext &C)
Definition: Type.cpp:160
bool any_of(R &&range, UnaryPredicate P)
Provide wrappers to std::any_of which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:1199
unsigned getAddressSpace() const
Definition: Globals.cpp:111
static FunctionType * get(Type *Result, ArrayRef< Type *> Params, bool isVarArg)
This static method is the primary way of constructing a FunctionType.
Definition: Type.cpp:296
Interval::pred_iterator pred_end(Interval *I)
Definition: Interval.h:115
op_range operands()
Definition: User.h:237
Value * getPointerOperand()
Definition: Instructions.h:284
static BasicBlock * Create(LLVMContext &Context, const Twine &Name="", Function *Parent=nullptr, BasicBlock *InsertBefore=nullptr)
Creates a new BasicBlock.
Definition: BasicBlock.h:99
arg_iterator arg_begin()
Definition: Function.h:695
self_iterator getIterator()
Definition: ilist_node.h:81
void setHasUWTable()
Definition: Function.h:589
static CastInst * CreatePointerCast(Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd)
Create a BitCast AddrSpaceCast, or a PtrToInt cast instruction.
const Function * getFunction() const
Return the function this instruction belongs to.
Definition: Instruction.cpp:59
CaseIt removeCase(CaseIt I)
This method removes the specified case and its successor from the switch instruction.
Sentinal value useful for loops.
Definition: Attributes.h:74
LLVMContext & getContext() const
getContext - Return a reference to the LLVMContext associated with this function. ...
Definition: Function.cpp:205
Class to represent profile counts.
Definition: Function.h:260
size_t size() const
Definition: SmallVector.h:52
static wasm::ValType getType(const TargetRegisterClass *RC)
Value * getIncomingValue(unsigned i) const
Return incoming value number x.
DomTreeNodeBase< NodeT > * getNode(const NodeT *BB) const
getNode - return the (Post)DominatorTree node for the specified basic block.
static PointerType * getInt8PtrTy(LLVMContext &C, unsigned AS=0)
Definition: Type.cpp:219
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
void setMetadata(unsigned KindID, MDNode *Node)
Set the metadata of the specified kind to the specified node.
Definition: Metadata.cpp:1222
BranchProbability getEdgeProbability(const BasicBlock *Src, unsigned IndexInSuccessors) const
Get an edge&#39;s probability, relative to other out-edges of the Src.
Intrinsic::ID getIntrinsicID() const
Return the intrinsic ID of this intrinsic.
Definition: IntrinsicInst.h:50
bool doesNotThrow() const
Determine if the function cannot unwind.
Definition: Function.h:533
size_type size() const
Definition: SmallPtrSet.h:92
bool hasAddressTaken() const
Returns true if there are any uses of this basic block other than direct branches, switches, etc.
Definition: BasicBlock.h:391
const InstListType & getInstList() const
Return the underlying instruction list container.
Definition: BasicBlock.h:333
typename vector_type::const_iterator iterator
Definition: SetVector.h:48
void addParamAttr(unsigned ArgNo, Attribute::AttrKind Kind)
Adds the attribute to the indicated argument.
Definition: InstrTypes.h:1397
Iterator for intrusive lists based on ilist_node.
SmallPtrSet - This class implements a set which is optimized for holding SmallSize or less elements...
Definition: SmallPtrSet.h:417
static PointerType * getUnqual(Type *ElementType)
This constructs a pointer to an object of the specified type in the generic address space (address sp...
Definition: DerivedTypes.h:559
void setIncomingBlock(unsigned i, BasicBlock *BB)
static SwitchInst * Create(Value *Value, BasicBlock *Default, unsigned NumCases, Instruction *InsertBefore=nullptr)
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.
CodeExtractor(ArrayRef< BasicBlock *> BBs, DominatorTree *DT=nullptr, bool AggregateArgs=false, BlockFrequencyInfo *BFI=nullptr, BranchProbabilityInfo *BPI=nullptr, AssumptionCache *AC=nullptr, bool AllowVarArgs=false, bool AllowAlloca=false, std::string Suffix="")
Create a code extractor for a sequence of blocks.
void setEdgeProbability(const BasicBlock *Src, unsigned IndexInSuccessors, BranchProbability Prob)
Set the raw edge probability for the given edge.
void setBlockFreq(const BasicBlock *BB, uint64_t Freq)
LLVM_NODISCARD T pop_back_val()
Definition: SmallVector.h:374
bool isEligible() const
Test whether this code extractor is eligible.
static Constant * get(Type *Ty, uint64_t V, bool isSigned=false)
If Ty is a vector type, return a Constant with a splat of the given value.
Definition: Constants.cpp:643
static ConstantInt * getSigned(IntegerType *Ty, int64_t V)
Return a ConstantInt with the specified value for the specified type.
Definition: Constants.cpp:657
static BranchInst * Create(BasicBlock *IfTrue, Instruction *InsertBefore=nullptr)
static PHINode * Create(Type *Ty, unsigned NumReservedValues, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
Constructors - NumReservedValues is a hint for the number of incoming edges that this phi node will h...
pred_range predecessors(BasicBlock *BB)
Definition: CFG.h:124
unsigned getNumIncomingValues() const
Return the number of incoming edges.
BlockFrequency getBlockFreq(const BasicBlock *BB) const
getblockFreq - Return block frequency.
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:132
FunctionType * getFunctionType() const
Returns the FunctionType for me.
Definition: Function.h:163
bool isLegalToShrinkwrapLifetimeMarkers(Instruction *AllocaAddr) const
Check if life time marker nodes can be hoisted/sunk into the outline region.
BasicBlock * findOrCreateBlockForHoisting(BasicBlock *CommonExitBlock)
Find or create a block within the outline region for placing hoisted code.
void push_back(pointer val)
Definition: ilist.h:311
iterator_range< user_iterator > users()
Definition: Value.h:399
Function::ProfileCount ProfileCount
This file provides various utilities for inspecting and working with the control flow graph in LLVM I...
pointer remove(iterator &IT)
Definition: ilist.h:249
Analysis providing branch probability information.
const DebugLoc & getDebugLoc() const
Return the debug location for this node as a DebugLoc.
Definition: Instruction.h:321
static IntegerType * getInt32Ty(LLVMContext &C)
Definition: Type.cpp:175
void setCondition(Value *V)
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:55
Represents a single loop in the control flow graph.
Definition: LoopInfo.h:506
StringRef getName() const
Return a constant reference to the value&#39;s name.
Definition: Value.cpp:214
BasicBlock * getIncomingBlock(unsigned i) const
Return incoming basic block number i.
const Function * getParent() const
Return the enclosing method, or null if none.
Definition: BasicBlock.h:106
#define I(x, y, z)
Definition: MD5.cpp:58
DomTreeNodeBase< NodeT > * addNewBlock(NodeT *BB, NodeT *DomBB)
Add a new node to the dominator tree information.
bool empty() const
Determine if the SetVector is empty or not.
Definition: SetVector.h:72
bool verifyFunction(const Function &F, raw_ostream *OS=nullptr)
Check a function for errors, useful for use when debugging a pass.
Definition: Verifier.cpp:4978
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
const BasicBlockListType & getBasicBlockList() const
Get the underlying elements of the Function...
Definition: Function.h:657
Rename collisions when linking (static functions).
Definition: GlobalValue.h:55
BasicBlock * splitBasicBlock(iterator I, const Twine &BBName="")
Split the basic block into two basic blocks at the specified instruction.
Definition: BasicBlock.cpp:407
Multiway switch.
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
user_iterator user_begin()
Definition: Value.h:375
const BasicBlock & front() const
Definition: Function.h:687
Module * getParent()
Get the module that this global value is contained inside of...
Definition: GlobalValue.h:575
LLVM Value Representation.
Definition: Value.h:72
Constant * getPersonalityFn() const
Get the personality function associated with this function.
Definition: Function.cpp:1384
void setDefaultDest(BasicBlock *DefaultCase)
A vector that has set insertion semantics.
Definition: SetVector.h:40
succ_range successors(Instruction *I)
Definition: CFG.h:259
void findAllocas(ValueSet &SinkCands, ValueSet &HoistCands, BasicBlock *&ExitBlock) const
Find the set of allocas whose life ranges are contained within the outlined region.
static const Function * getParent(const Value *V)
AttributeSet getFnAttributes() const
The function attributes are returned.
void moveBefore(Instruction *MovePos)
Unlink this instruction from its current basic block and insert it into the basic block that MovePos ...
Definition: Instruction.cpp:86
BasicBlock * SplitBlock(BasicBlock *Old, Instruction *SplitPt, DominatorTree *DT=nullptr, LoopInfo *LI=nullptr, MemorySSAUpdater *MSSAU=nullptr)
Split the specified block at the specified instruction - everything before SplitPt stays in Old and e...
void addFnAttr(Attribute::AttrKind Kind)
Add function attributes to this function.
Definition: Function.h:229
void setPersonalityFn(Constant *Fn)
Definition: Function.cpp:1389
static BranchProbability getZero()
const Value * stripInBoundsConstantOffsets() const
Strip off pointer casts and all-constant inbounds GEPs.
Definition: Value.cpp:548
#define LLVM_DEBUG(X)
Definition: Debug.h:122
Value * getPointerOperand()
Definition: Instructions.h:412
Optional< uint64_t > getProfileCountFromFreq(uint64_t Freq) const
Returns the estimated profile count of Freq.
bool empty() const
empty - Check if the array is empty.
Definition: ArrayRef.h:143
A wrapper class for inspecting calls to intrinsic functions.
Definition: IntrinsicInst.h:43
const BasicBlock * getParent() const
Definition: Instruction.h:66
an instruction to allocate memory on the stack
Definition: Instructions.h:59
user_iterator user_end()
Definition: Value.h:383