LLVM  7.0.0svn
LoopUtils.cpp
Go to the documentation of this file.
1 //===-- LoopUtils.cpp - Loop Utility functions -------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines common loop utility functions.
11 //
12 //===----------------------------------------------------------------------===//
13 
15 #include "llvm/ADT/ScopeExit.h"
20 #include "llvm/Analysis/LoopInfo.h"
21 #include "llvm/Analysis/LoopPass.h"
29 #include "llvm/IR/Dominators.h"
30 #include "llvm/IR/Instructions.h"
31 #include "llvm/IR/Module.h"
32 #include "llvm/IR/PatternMatch.h"
33 #include "llvm/IR/ValueHandle.h"
34 #include "llvm/Pass.h"
35 #include "llvm/Support/Debug.h"
36 #include "llvm/Support/KnownBits.h"
38 
39 using namespace llvm;
40 using namespace llvm::PatternMatch;
41 
42 #define DEBUG_TYPE "loop-utils"
43 
46  for (User::op_iterator Use = I->op_begin(), E = I->op_end(); Use != E; ++Use)
47  if (!Set.count(dyn_cast<Instruction>(*Use)))
48  return false;
49  return true;
50 }
51 
53  switch (Kind) {
54  default:
55  break;
56  case RK_IntegerAdd:
57  case RK_IntegerMult:
58  case RK_IntegerOr:
59  case RK_IntegerAnd:
60  case RK_IntegerXor:
61  case RK_IntegerMinMax:
62  return true;
63  }
64  return false;
65 }
66 
68  return (Kind != RK_NoRecurrence) && !isIntegerRecurrenceKind(Kind);
69 }
70 
72  switch (Kind) {
73  default:
74  break;
75  case RK_IntegerAdd:
76  case RK_IntegerMult:
77  case RK_FloatAdd:
78  case RK_FloatMult:
79  return true;
80  }
81  return false;
82 }
83 
84 /// Determines if Phi may have been type-promoted. If Phi has a single user
85 /// that ANDs the Phi with a type mask, return the user. RT is updated to
86 /// account for the narrower bit width represented by the mask, and the AND
87 /// instruction is added to CI.
91  if (!Phi->hasOneUse())
92  return Phi;
93 
94  const APInt *M = nullptr;
95  Instruction *I, *J = cast<Instruction>(Phi->use_begin()->getUser());
96 
97  // Matches either I & 2^x-1 or 2^x-1 & I. If we find a match, we update RT
98  // with a new integer type of the corresponding bit width.
99  if (match(J, m_c_And(m_Instruction(I), m_APInt(M)))) {
100  int32_t Bits = (*M + 1).exactLogBase2();
101  if (Bits > 0) {
102  RT = IntegerType::get(Phi->getContext(), Bits);
103  Visited.insert(Phi);
104  CI.insert(J);
105  return J;
106  }
107  }
108  return Phi;
109 }
110 
111 /// Compute the minimal bit width needed to represent a reduction whose exit
112 /// instruction is given by Exit.
113 static std::pair<Type *, bool> computeRecurrenceType(Instruction *Exit,
114  DemandedBits *DB,
115  AssumptionCache *AC,
116  DominatorTree *DT) {
117  bool IsSigned = false;
118  const DataLayout &DL = Exit->getModule()->getDataLayout();
119  uint64_t MaxBitWidth = DL.getTypeSizeInBits(Exit->getType());
120 
121  if (DB) {
122  // Use the demanded bits analysis to determine the bits that are live out
123  // of the exit instruction, rounding up to the nearest power of two. If the
124  // use of demanded bits results in a smaller bit width, we know the value
125  // must be positive (i.e., IsSigned = false), because if this were not the
126  // case, the sign bit would have been demanded.
127  auto Mask = DB->getDemandedBits(Exit);
128  MaxBitWidth = Mask.getBitWidth() - Mask.countLeadingZeros();
129  }
130 
131  if (MaxBitWidth == DL.getTypeSizeInBits(Exit->getType()) && AC && DT) {
132  // If demanded bits wasn't able to limit the bit width, we can try to use
133  // value tracking instead. This can be the case, for example, if the value
134  // may be negative.
135  auto NumSignBits = ComputeNumSignBits(Exit, DL, 0, AC, nullptr, DT);
136  auto NumTypeBits = DL.getTypeSizeInBits(Exit->getType());
137  MaxBitWidth = NumTypeBits - NumSignBits;
138  KnownBits Bits = computeKnownBits(Exit, DL);
139  if (!Bits.isNonNegative()) {
140  // If the value is not known to be non-negative, we set IsSigned to true,
141  // meaning that we will use sext instructions instead of zext
142  // instructions to restore the original type.
143  IsSigned = true;
144  if (!Bits.isNegative())
145  // If the value is not known to be negative, we don't known what the
146  // upper bit is, and therefore, we don't know what kind of extend we
147  // will need. In this case, just increase the bit width by one bit and
148  // use sext.
149  ++MaxBitWidth;
150  }
151  }
152  if (!isPowerOf2_64(MaxBitWidth))
153  MaxBitWidth = NextPowerOf2(MaxBitWidth);
154 
155  return std::make_pair(Type::getIntNTy(Exit->getContext(), MaxBitWidth),
156  IsSigned);
157 }
158 
159 /// Collect cast instructions that can be ignored in the vectorizer's cost
160 /// model, given a reduction exit value and the minimal type in which the
161 /// reduction can be represented.
162 static void collectCastsToIgnore(Loop *TheLoop, Instruction *Exit,
163  Type *RecurrenceType,
165 
168  Worklist.push_back(Exit);
169 
170  while (!Worklist.empty()) {
171  Instruction *Val = Worklist.pop_back_val();
172  Visited.insert(Val);
173  if (auto *Cast = dyn_cast<CastInst>(Val))
174  if (Cast->getSrcTy() == RecurrenceType) {
175  // If the source type of a cast instruction is equal to the recurrence
176  // type, it will be eliminated, and should be ignored in the vectorizer
177  // cost model.
178  Casts.insert(Cast);
179  continue;
180  }
181 
182  // Add all operands to the work list if they are loop-varying values that
183  // we haven't yet visited.
184  for (Value *O : cast<User>(Val)->operands())
185  if (auto *I = dyn_cast<Instruction>(O))
186  if (TheLoop->contains(I) && !Visited.count(I))
187  Worklist.push_back(I);
188  }
189 }
190 
192  Loop *TheLoop, bool HasFunNoNaNAttr,
193  RecurrenceDescriptor &RedDes,
194  DemandedBits *DB,
195  AssumptionCache *AC,
196  DominatorTree *DT) {
197  if (Phi->getNumIncomingValues() != 2)
198  return false;
199 
200  // Reduction variables are only found in the loop header block.
201  if (Phi->getParent() != TheLoop->getHeader())
202  return false;
203 
204  // Obtain the reduction start value from the value that comes from the loop
205  // preheader.
206  Value *RdxStart = Phi->getIncomingValueForBlock(TheLoop->getLoopPreheader());
207 
208  // ExitInstruction is the single value which is used outside the loop.
209  // We only allow for a single reduction value to be used outside the loop.
210  // This includes users of the reduction, variables (which form a cycle
211  // which ends in the phi node).
212  Instruction *ExitInstruction = nullptr;
213  // Indicates that we found a reduction operation in our scan.
214  bool FoundReduxOp = false;
215 
216  // We start with the PHI node and scan for all of the users of this
217  // instruction. All users must be instructions that can be used as reduction
218  // variables (such as ADD). We must have a single out-of-block user. The cycle
219  // must include the original PHI.
220  bool FoundStartPHI = false;
221 
222  // To recognize min/max patterns formed by a icmp select sequence, we store
223  // the number of instruction we saw from the recognized min/max pattern,
224  // to make sure we only see exactly the two instructions.
225  unsigned NumCmpSelectPatternInst = 0;
226  InstDesc ReduxDesc(false, nullptr);
227 
228  // Data used for determining if the recurrence has been type-promoted.
229  Type *RecurrenceType = Phi->getType();
231  Instruction *Start = Phi;
232  bool IsSigned = false;
233 
234  SmallPtrSet<Instruction *, 8> VisitedInsts;
236 
237  // Return early if the recurrence kind does not match the type of Phi. If the
238  // recurrence kind is arithmetic, we attempt to look through AND operations
239  // resulting from the type promotion performed by InstCombine. Vector
240  // operations are not limited to the legal integer widths, so we may be able
241  // to evaluate the reduction in the narrower width.
242  if (RecurrenceType->isFloatingPointTy()) {
243  if (!isFloatingPointRecurrenceKind(Kind))
244  return false;
245  } else {
246  if (!isIntegerRecurrenceKind(Kind))
247  return false;
248  if (isArithmeticRecurrenceKind(Kind))
249  Start = lookThroughAnd(Phi, RecurrenceType, VisitedInsts, CastInsts);
250  }
251 
252  Worklist.push_back(Start);
253  VisitedInsts.insert(Start);
254 
255  // A value in the reduction can be used:
256  // - By the reduction:
257  // - Reduction operation:
258  // - One use of reduction value (safe).
259  // - Multiple use of reduction value (not safe).
260  // - PHI:
261  // - All uses of the PHI must be the reduction (safe).
262  // - Otherwise, not safe.
263  // - By instructions outside of the loop (safe).
264  // * One value may have several outside users, but all outside
265  // uses must be of the same value.
266  // - By an instruction that is not part of the reduction (not safe).
267  // This is either:
268  // * An instruction type other than PHI or the reduction operation.
269  // * A PHI in the header other than the initial PHI.
270  while (!Worklist.empty()) {
271  Instruction *Cur = Worklist.back();
272  Worklist.pop_back();
273 
274  // No Users.
275  // If the instruction has no users then this is a broken chain and can't be
276  // a reduction variable.
277  if (Cur->use_empty())
278  return false;
279 
280  bool IsAPhi = isa<PHINode>(Cur);
281 
282  // A header PHI use other than the original PHI.
283  if (Cur != Phi && IsAPhi && Cur->getParent() == Phi->getParent())
284  return false;
285 
286  // Reductions of instructions such as Div, and Sub is only possible if the
287  // LHS is the reduction variable.
288  if (!Cur->isCommutative() && !IsAPhi && !isa<SelectInst>(Cur) &&
289  !isa<ICmpInst>(Cur) && !isa<FCmpInst>(Cur) &&
290  !VisitedInsts.count(dyn_cast<Instruction>(Cur->getOperand(0))))
291  return false;
292 
293  // Any reduction instruction must be of one of the allowed kinds. We ignore
294  // the starting value (the Phi or an AND instruction if the Phi has been
295  // type-promoted).
296  if (Cur != Start) {
297  ReduxDesc = isRecurrenceInstr(Cur, Kind, ReduxDesc, HasFunNoNaNAttr);
298  if (!ReduxDesc.isRecurrence())
299  return false;
300  }
301 
302  // A reduction operation must only have one use of the reduction value.
303  if (!IsAPhi && Kind != RK_IntegerMinMax && Kind != RK_FloatMinMax &&
304  hasMultipleUsesOf(Cur, VisitedInsts))
305  return false;
306 
307  // All inputs to a PHI node must be a reduction value.
308  if (IsAPhi && Cur != Phi && !areAllUsesIn(Cur, VisitedInsts))
309  return false;
310 
311  if (Kind == RK_IntegerMinMax &&
312  (isa<ICmpInst>(Cur) || isa<SelectInst>(Cur)))
313  ++NumCmpSelectPatternInst;
314  if (Kind == RK_FloatMinMax && (isa<FCmpInst>(Cur) || isa<SelectInst>(Cur)))
315  ++NumCmpSelectPatternInst;
316 
317  // Check whether we found a reduction operator.
318  FoundReduxOp |= !IsAPhi && Cur != Start;
319 
320  // Process users of current instruction. Push non-PHI nodes after PHI nodes
321  // onto the stack. This way we are going to have seen all inputs to PHI
322  // nodes once we get to them.
325  for (User *U : Cur->users()) {
326  Instruction *UI = cast<Instruction>(U);
327 
328  // Check if we found the exit user.
329  BasicBlock *Parent = UI->getParent();
330  if (!TheLoop->contains(Parent)) {
331  // If we already know this instruction is used externally, move on to
332  // the next user.
333  if (ExitInstruction == Cur)
334  continue;
335 
336  // Exit if you find multiple values used outside or if the header phi
337  // node is being used. In this case the user uses the value of the
338  // previous iteration, in which case we would loose "VF-1" iterations of
339  // the reduction operation if we vectorize.
340  if (ExitInstruction != nullptr || Cur == Phi)
341  return false;
342 
343  // The instruction used by an outside user must be the last instruction
344  // before we feed back to the reduction phi. Otherwise, we loose VF-1
345  // operations on the value.
346  if (!is_contained(Phi->operands(), Cur))
347  return false;
348 
349  ExitInstruction = Cur;
350  continue;
351  }
352 
353  // Process instructions only once (termination). Each reduction cycle
354  // value must only be used once, except by phi nodes and min/max
355  // reductions which are represented as a cmp followed by a select.
356  InstDesc IgnoredVal(false, nullptr);
357  if (VisitedInsts.insert(UI).second) {
358  if (isa<PHINode>(UI))
359  PHIs.push_back(UI);
360  else
361  NonPHIs.push_back(UI);
362  } else if (!isa<PHINode>(UI) &&
363  ((!isa<FCmpInst>(UI) && !isa<ICmpInst>(UI) &&
364  !isa<SelectInst>(UI)) ||
365  !isMinMaxSelectCmpPattern(UI, IgnoredVal).isRecurrence()))
366  return false;
367 
368  // Remember that we completed the cycle.
369  if (UI == Phi)
370  FoundStartPHI = true;
371  }
372  Worklist.append(PHIs.begin(), PHIs.end());
373  Worklist.append(NonPHIs.begin(), NonPHIs.end());
374  }
375 
376  // This means we have seen one but not the other instruction of the
377  // pattern or more than just a select and cmp.
378  if ((Kind == RK_IntegerMinMax || Kind == RK_FloatMinMax) &&
379  NumCmpSelectPatternInst != 2)
380  return false;
381 
382  if (!FoundStartPHI || !FoundReduxOp || !ExitInstruction)
383  return false;
384 
385  if (Start != Phi) {
386  // If the starting value is not the same as the phi node, we speculatively
387  // looked through an 'and' instruction when evaluating a potential
388  // arithmetic reduction to determine if it may have been type-promoted.
389  //
390  // We now compute the minimal bit width that is required to represent the
391  // reduction. If this is the same width that was indicated by the 'and', we
392  // can represent the reduction in the smaller type. The 'and' instruction
393  // will be eliminated since it will essentially be a cast instruction that
394  // can be ignore in the cost model. If we compute a different type than we
395  // did when evaluating the 'and', the 'and' will not be eliminated, and we
396  // will end up with different kinds of operations in the recurrence
397  // expression (e.g., RK_IntegerAND, RK_IntegerADD). We give up if this is
398  // the case.
399  //
400  // The vectorizer relies on InstCombine to perform the actual
401  // type-shrinking. It does this by inserting instructions to truncate the
402  // exit value of the reduction to the width indicated by RecurrenceType and
403  // then extend this value back to the original width. If IsSigned is false,
404  // a 'zext' instruction will be generated; otherwise, a 'sext' will be
405  // used.
406  //
407  // TODO: We should not rely on InstCombine to rewrite the reduction in the
408  // smaller type. We should just generate a correctly typed expression
409  // to begin with.
410  Type *ComputedType;
411  std::tie(ComputedType, IsSigned) =
412  computeRecurrenceType(ExitInstruction, DB, AC, DT);
413  if (ComputedType != RecurrenceType)
414  return false;
415 
416  // The recurrence expression will be represented in a narrower type. If
417  // there are any cast instructions that will be unnecessary, collect them
418  // in CastInsts. Note that the 'and' instruction was already included in
419  // this list.
420  //
421  // TODO: A better way to represent this may be to tag in some way all the
422  // instructions that are a part of the reduction. The vectorizer cost
423  // model could then apply the recurrence type to these instructions,
424  // without needing a white list of instructions to ignore.
425  collectCastsToIgnore(TheLoop, ExitInstruction, RecurrenceType, CastInsts);
426  }
427 
428  // We found a reduction var if we have reached the original phi node and we
429  // only have a single instruction with out-of-loop users.
430 
431  // The ExitInstruction(Instruction which is allowed to have out-of-loop users)
432  // is saved as part of the RecurrenceDescriptor.
433 
434  // Save the description of this reduction variable.
436  RdxStart, ExitInstruction, Kind, ReduxDesc.getMinMaxKind(),
437  ReduxDesc.getUnsafeAlgebraInst(), RecurrenceType, IsSigned, CastInsts);
438  RedDes = RD;
439 
440  return true;
441 }
442 
443 /// Returns true if the instruction is a Select(ICmp(X, Y), X, Y) instruction
444 /// pattern corresponding to a min(X, Y) or max(X, Y).
447 
448  assert((isa<ICmpInst>(I) || isa<FCmpInst>(I) || isa<SelectInst>(I)) &&
449  "Expect a select instruction");
450  Instruction *Cmp = nullptr;
451  SelectInst *Select = nullptr;
452 
453  // We must handle the select(cmp()) as a single instruction. Advance to the
454  // select.
455  if ((Cmp = dyn_cast<ICmpInst>(I)) || (Cmp = dyn_cast<FCmpInst>(I))) {
456  if (!Cmp->hasOneUse() || !(Select = dyn_cast<SelectInst>(*I->user_begin())))
457  return InstDesc(false, I);
458  return InstDesc(Select, Prev.getMinMaxKind());
459  }
460 
461  // Only handle single use cases for now.
462  if (!(Select = dyn_cast<SelectInst>(I)))
463  return InstDesc(false, I);
464  if (!(Cmp = dyn_cast<ICmpInst>(I->getOperand(0))) &&
465  !(Cmp = dyn_cast<FCmpInst>(I->getOperand(0))))
466  return InstDesc(false, I);
467  if (!Cmp->hasOneUse())
468  return InstDesc(false, I);
469 
470  Value *CmpLeft;
471  Value *CmpRight;
472 
473  // Look for a min/max pattern.
474  if (m_UMin(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
475  return InstDesc(Select, MRK_UIntMin);
476  else if (m_UMax(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
477  return InstDesc(Select, MRK_UIntMax);
478  else if (m_SMax(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
479  return InstDesc(Select, MRK_SIntMax);
480  else if (m_SMin(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
481  return InstDesc(Select, MRK_SIntMin);
482  else if (m_OrdFMin(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
483  return InstDesc(Select, MRK_FloatMin);
484  else if (m_OrdFMax(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
485  return InstDesc(Select, MRK_FloatMax);
486  else if (m_UnordFMin(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
487  return InstDesc(Select, MRK_FloatMin);
488  else if (m_UnordFMax(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
489  return InstDesc(Select, MRK_FloatMax);
490 
491  return InstDesc(false, I);
492 }
493 
496  InstDesc &Prev, bool HasFunNoNaNAttr) {
497  bool FP = I->getType()->isFloatingPointTy();
498  Instruction *UAI = Prev.getUnsafeAlgebraInst();
499  if (!UAI && FP && !I->isFast())
500  UAI = I; // Found an unsafe (unvectorizable) algebra instruction.
501 
502  switch (I->getOpcode()) {
503  default:
504  return InstDesc(false, I);
505  case Instruction::PHI:
506  return InstDesc(I, Prev.getMinMaxKind(), Prev.getUnsafeAlgebraInst());
507  case Instruction::Sub:
508  case Instruction::Add:
509  return InstDesc(Kind == RK_IntegerAdd, I);
510  case Instruction::Mul:
511  return InstDesc(Kind == RK_IntegerMult, I);
512  case Instruction::And:
513  return InstDesc(Kind == RK_IntegerAnd, I);
514  case Instruction::Or:
515  return InstDesc(Kind == RK_IntegerOr, I);
516  case Instruction::Xor:
517  return InstDesc(Kind == RK_IntegerXor, I);
518  case Instruction::FMul:
519  return InstDesc(Kind == RK_FloatMult, I, UAI);
520  case Instruction::FSub:
521  case Instruction::FAdd:
522  return InstDesc(Kind == RK_FloatAdd, I, UAI);
523  case Instruction::FCmp:
524  case Instruction::ICmp:
525  case Instruction::Select:
526  if (Kind != RK_IntegerMinMax &&
527  (!HasFunNoNaNAttr || Kind != RK_FloatMinMax))
528  return InstDesc(false, I);
529  return isMinMaxSelectCmpPattern(I, Prev);
530  }
531 }
532 
535  unsigned NumUses = 0;
536  for (User::op_iterator Use = I->op_begin(), E = I->op_end(); Use != E;
537  ++Use) {
538  if (Insts.count(dyn_cast<Instruction>(*Use)))
539  ++NumUses;
540  if (NumUses > 1)
541  return true;
542  }
543 
544  return false;
545 }
547  RecurrenceDescriptor &RedDes,
548  DemandedBits *DB, AssumptionCache *AC,
549  DominatorTree *DT) {
550 
551  BasicBlock *Header = TheLoop->getHeader();
552  Function &F = *Header->getParent();
553  bool HasFunNoNaNAttr =
554  F.getFnAttribute("no-nans-fp-math").getValueAsString() == "true";
555 
556  if (AddReductionVar(Phi, RK_IntegerAdd, TheLoop, HasFunNoNaNAttr, RedDes, DB,
557  AC, DT)) {
558  LLVM_DEBUG(dbgs() << "Found an ADD reduction PHI." << *Phi << "\n");
559  return true;
560  }
561  if (AddReductionVar(Phi, RK_IntegerMult, TheLoop, HasFunNoNaNAttr, RedDes, DB,
562  AC, DT)) {
563  LLVM_DEBUG(dbgs() << "Found a MUL reduction PHI." << *Phi << "\n");
564  return true;
565  }
566  if (AddReductionVar(Phi, RK_IntegerOr, TheLoop, HasFunNoNaNAttr, RedDes, DB,
567  AC, DT)) {
568  LLVM_DEBUG(dbgs() << "Found an OR reduction PHI." << *Phi << "\n");
569  return true;
570  }
571  if (AddReductionVar(Phi, RK_IntegerAnd, TheLoop, HasFunNoNaNAttr, RedDes, DB,
572  AC, DT)) {
573  LLVM_DEBUG(dbgs() << "Found an AND reduction PHI." << *Phi << "\n");
574  return true;
575  }
576  if (AddReductionVar(Phi, RK_IntegerXor, TheLoop, HasFunNoNaNAttr, RedDes, DB,
577  AC, DT)) {
578  LLVM_DEBUG(dbgs() << "Found a XOR reduction PHI." << *Phi << "\n");
579  return true;
580  }
581  if (AddReductionVar(Phi, RK_IntegerMinMax, TheLoop, HasFunNoNaNAttr, RedDes,
582  DB, AC, DT)) {
583  LLVM_DEBUG(dbgs() << "Found a MINMAX reduction PHI." << *Phi << "\n");
584  return true;
585  }
586  if (AddReductionVar(Phi, RK_FloatMult, TheLoop, HasFunNoNaNAttr, RedDes, DB,
587  AC, DT)) {
588  LLVM_DEBUG(dbgs() << "Found an FMult reduction PHI." << *Phi << "\n");
589  return true;
590  }
591  if (AddReductionVar(Phi, RK_FloatAdd, TheLoop, HasFunNoNaNAttr, RedDes, DB,
592  AC, DT)) {
593  LLVM_DEBUG(dbgs() << "Found an FAdd reduction PHI." << *Phi << "\n");
594  return true;
595  }
596  if (AddReductionVar(Phi, RK_FloatMinMax, TheLoop, HasFunNoNaNAttr, RedDes, DB,
597  AC, DT)) {
598  LLVM_DEBUG(dbgs() << "Found an float MINMAX reduction PHI." << *Phi
599  << "\n");
600  return true;
601  }
602  // Not a reduction of known type.
603  return false;
604 }
605 
607  PHINode *Phi, Loop *TheLoop,
609 
610  // Ensure the phi node is in the loop header and has two incoming values.
611  if (Phi->getParent() != TheLoop->getHeader() ||
612  Phi->getNumIncomingValues() != 2)
613  return false;
614 
615  // Ensure the loop has a preheader and a single latch block. The loop
616  // vectorizer will need the latch to set up the next iteration of the loop.
617  auto *Preheader = TheLoop->getLoopPreheader();
618  auto *Latch = TheLoop->getLoopLatch();
619  if (!Preheader || !Latch)
620  return false;
621 
622  // Ensure the phi node's incoming blocks are the loop preheader and latch.
623  if (Phi->getBasicBlockIndex(Preheader) < 0 ||
624  Phi->getBasicBlockIndex(Latch) < 0)
625  return false;
626 
627  // Get the previous value. The previous value comes from the latch edge while
628  // the initial value comes form the preheader edge.
629  auto *Previous = dyn_cast<Instruction>(Phi->getIncomingValueForBlock(Latch));
630  if (!Previous || !TheLoop->contains(Previous) || isa<PHINode>(Previous) ||
631  SinkAfter.count(Previous)) // Cannot rely on dominance due to motion.
632  return false;
633 
634  // Ensure every user of the phi node is dominated by the previous value.
635  // The dominance requirement ensures the loop vectorizer will not need to
636  // vectorize the initial value prior to the first iteration of the loop.
637  // TODO: Consider extending this sinking to handle other kinds of instructions
638  // and expressions, beyond sinking a single cast past Previous.
639  if (Phi->hasOneUse()) {
640  auto *I = Phi->user_back();
641  if (I->isCast() && (I->getParent() == Phi->getParent()) && I->hasOneUse() &&
642  DT->dominates(Previous, I->user_back())) {
643  if (!DT->dominates(Previous, I)) // Otherwise we're good w/o sinking.
644  SinkAfter[I] = Previous;
645  return true;
646  }
647  }
648 
649  for (User *U : Phi->users())
650  if (auto *I = dyn_cast<Instruction>(U)) {
651  if (!DT->dominates(Previous, I))
652  return false;
653  }
654 
655  return true;
656 }
657 
658 /// This function returns the identity element (or neutral element) for
659 /// the operation K.
661  Type *Tp) {
662  switch (K) {
663  case RK_IntegerXor:
664  case RK_IntegerAdd:
665  case RK_IntegerOr:
666  // Adding, Xoring, Oring zero to a number does not change it.
667  return ConstantInt::get(Tp, 0);
668  case RK_IntegerMult:
669  // Multiplying a number by 1 does not change it.
670  return ConstantInt::get(Tp, 1);
671  case RK_IntegerAnd:
672  // AND-ing a number with an all-1 value does not change it.
673  return ConstantInt::get(Tp, -1, true);
674  case RK_FloatMult:
675  // Multiplying a number by 1 does not change it.
676  return ConstantFP::get(Tp, 1.0L);
677  case RK_FloatAdd:
678  // Adding zero to a number does not change it.
679  return ConstantFP::get(Tp, 0.0L);
680  default:
681  llvm_unreachable("Unknown recurrence kind");
682  }
683 }
684 
685 /// This function translates the recurrence kind to an LLVM binary operator.
687  switch (Kind) {
688  case RK_IntegerAdd:
689  return Instruction::Add;
690  case RK_IntegerMult:
691  return Instruction::Mul;
692  case RK_IntegerOr:
693  return Instruction::Or;
694  case RK_IntegerAnd:
695  return Instruction::And;
696  case RK_IntegerXor:
697  return Instruction::Xor;
698  case RK_FloatMult:
699  return Instruction::FMul;
700  case RK_FloatAdd:
701  return Instruction::FAdd;
702  case RK_IntegerMinMax:
703  return Instruction::ICmp;
704  case RK_FloatMinMax:
705  return Instruction::FCmp;
706  default:
707  llvm_unreachable("Unknown recurrence operation");
708  }
709 }
710 
713  Value *Left, Value *Right) {
715  switch (RK) {
716  default:
717  llvm_unreachable("Unknown min/max recurrence kind");
718  case MRK_UIntMin:
719  P = CmpInst::ICMP_ULT;
720  break;
721  case MRK_UIntMax:
722  P = CmpInst::ICMP_UGT;
723  break;
724  case MRK_SIntMin:
725  P = CmpInst::ICMP_SLT;
726  break;
727  case MRK_SIntMax:
728  P = CmpInst::ICMP_SGT;
729  break;
730  case MRK_FloatMin:
731  P = CmpInst::FCMP_OLT;
732  break;
733  case MRK_FloatMax:
734  P = CmpInst::FCMP_OGT;
735  break;
736  }
737 
738  // We only match FP sequences that are 'fast', so we can unconditionally
739  // set it on any generated instructions.
740  IRBuilder<>::FastMathFlagGuard FMFG(Builder);
741  FastMathFlags FMF;
742  FMF.setFast();
743  Builder.setFastMathFlags(FMF);
744 
745  Value *Cmp;
746  if (RK == MRK_FloatMin || RK == MRK_FloatMax)
747  Cmp = Builder.CreateFCmp(P, Left, Right, "rdx.minmax.cmp");
748  else
749  Cmp = Builder.CreateICmp(P, Left, Right, "rdx.minmax.cmp");
750 
751  Value *Select = Builder.CreateSelect(Cmp, Left, Right, "rdx.minmax.select");
752  return Select;
753 }
754 
755 InductionDescriptor::InductionDescriptor(Value *Start, InductionKind K,
756  const SCEV *Step, BinaryOperator *BOp,
758  : StartValue(Start), IK(K), Step(Step), InductionBinOp(BOp) {
759  assert(IK != IK_NoInduction && "Not an induction");
760 
761  // Start value type should match the induction kind and the value
762  // itself should not be null.
763  assert(StartValue && "StartValue is null");
764  assert((IK != IK_PtrInduction || StartValue->getType()->isPointerTy()) &&
765  "StartValue is not a pointer for pointer induction");
766  assert((IK != IK_IntInduction || StartValue->getType()->isIntegerTy()) &&
767  "StartValue is not an integer for integer induction");
768 
769  // Check the Step Value. It should be non-zero integer value.
770  assert((!getConstIntStepValue() || !getConstIntStepValue()->isZero()) &&
771  "Step value is zero");
772 
773  assert((IK != IK_PtrInduction || getConstIntStepValue()) &&
774  "Step value should be constant for pointer induction");
775  assert((IK == IK_FpInduction || Step->getType()->isIntegerTy()) &&
776  "StepValue is not an integer");
777 
778  assert((IK != IK_FpInduction || Step->getType()->isFloatingPointTy()) &&
779  "StepValue is not FP for FpInduction");
780  assert((IK != IK_FpInduction || (InductionBinOp &&
781  (InductionBinOp->getOpcode() == Instruction::FAdd ||
782  InductionBinOp->getOpcode() == Instruction::FSub))) &&
783  "Binary opcode should be specified for FP induction");
784 
785  if (Casts) {
786  for (auto &Inst : *Casts) {
787  RedundantCasts.push_back(Inst);
788  }
789  }
790 }
791 
793  ConstantInt *ConstStep = getConstIntStepValue();
794  if (ConstStep && (ConstStep->isOne() || ConstStep->isMinusOne()))
795  return ConstStep->getSExtValue();
796  return 0;
797 }
798 
800  if (isa<SCEVConstant>(Step))
801  return dyn_cast<ConstantInt>(cast<SCEVConstant>(Step)->getValue());
802  return nullptr;
803 }
804 
806  ScalarEvolution *SE,
807  const DataLayout& DL) const {
808 
809  SCEVExpander Exp(*SE, DL, "induction");
810  assert(Index->getType() == Step->getType() &&
811  "Index type does not match StepValue type");
812  switch (IK) {
813  case IK_IntInduction: {
814  assert(Index->getType() == StartValue->getType() &&
815  "Index type does not match StartValue type");
816 
817  // FIXME: Theoretically, we can call getAddExpr() of ScalarEvolution
818  // and calculate (Start + Index * Step) for all cases, without
819  // special handling for "isOne" and "isMinusOne".
820  // But in the real life the result code getting worse. We mix SCEV
821  // expressions and ADD/SUB operations and receive redundant
822  // intermediate values being calculated in different ways and
823  // Instcombine is unable to reduce them all.
824 
825  if (getConstIntStepValue() &&
826  getConstIntStepValue()->isMinusOne())
827  return B.CreateSub(StartValue, Index);
828  if (getConstIntStepValue() &&
829  getConstIntStepValue()->isOne())
830  return B.CreateAdd(StartValue, Index);
831  const SCEV *S = SE->getAddExpr(SE->getSCEV(StartValue),
832  SE->getMulExpr(Step, SE->getSCEV(Index)));
833  return Exp.expandCodeFor(S, StartValue->getType(), &*B.GetInsertPoint());
834  }
835  case IK_PtrInduction: {
836  assert(isa<SCEVConstant>(Step) &&
837  "Expected constant step for pointer induction");
838  const SCEV *S = SE->getMulExpr(SE->getSCEV(Index), Step);
839  Index = Exp.expandCodeFor(S, Index->getType(), &*B.GetInsertPoint());
840  return B.CreateGEP(nullptr, StartValue, Index);
841  }
842  case IK_FpInduction: {
843  assert(Step->getType()->isFloatingPointTy() && "Expected FP Step value");
844  assert(InductionBinOp &&
845  (InductionBinOp->getOpcode() == Instruction::FAdd ||
846  InductionBinOp->getOpcode() == Instruction::FSub) &&
847  "Original bin op should be defined for FP induction");
848 
849  Value *StepValue = cast<SCEVUnknown>(Step)->getValue();
850 
851  // Floating point operations had to be 'fast' to enable the induction.
852  FastMathFlags Flags;
853  Flags.setFast();
854 
855  Value *MulExp = B.CreateFMul(StepValue, Index);
856  if (isa<Instruction>(MulExp))
857  // We have to check, the MulExp may be a constant.
858  cast<Instruction>(MulExp)->setFastMathFlags(Flags);
859 
860  Value *BOp = B.CreateBinOp(InductionBinOp->getOpcode() , StartValue,
861  MulExp, "induction");
862  if (isa<Instruction>(BOp))
863  cast<Instruction>(BOp)->setFastMathFlags(Flags);
864 
865  return BOp;
866  }
867  case IK_NoInduction:
868  return nullptr;
869  }
870  llvm_unreachable("invalid enum");
871 }
872 
874  ScalarEvolution *SE,
876 
877  // Here we only handle FP induction variables.
878  assert(Phi->getType()->isFloatingPointTy() && "Unexpected Phi type");
879 
880  if (TheLoop->getHeader() != Phi->getParent())
881  return false;
882 
883  // The loop may have multiple entrances or multiple exits; we can analyze
884  // this phi if it has a unique entry value and a unique backedge value.
885  if (Phi->getNumIncomingValues() != 2)
886  return false;
887  Value *BEValue = nullptr, *StartValue = nullptr;
888  if (TheLoop->contains(Phi->getIncomingBlock(0))) {
889  BEValue = Phi->getIncomingValue(0);
890  StartValue = Phi->getIncomingValue(1);
891  } else {
892  assert(TheLoop->contains(Phi->getIncomingBlock(1)) &&
893  "Unexpected Phi node in the loop");
894  BEValue = Phi->getIncomingValue(1);
895  StartValue = Phi->getIncomingValue(0);
896  }
897 
898  BinaryOperator *BOp = dyn_cast<BinaryOperator>(BEValue);
899  if (!BOp)
900  return false;
901 
902  Value *Addend = nullptr;
903  if (BOp->getOpcode() == Instruction::FAdd) {
904  if (BOp->getOperand(0) == Phi)
905  Addend = BOp->getOperand(1);
906  else if (BOp->getOperand(1) == Phi)
907  Addend = BOp->getOperand(0);
908  } else if (BOp->getOpcode() == Instruction::FSub)
909  if (BOp->getOperand(0) == Phi)
910  Addend = BOp->getOperand(1);
911 
912  if (!Addend)
913  return false;
914 
915  // The addend should be loop invariant
916  if (auto *I = dyn_cast<Instruction>(Addend))
917  if (TheLoop->contains(I))
918  return false;
919 
920  // FP Step has unknown SCEV
921  const SCEV *Step = SE->getUnknown(Addend);
922  D = InductionDescriptor(StartValue, IK_FpInduction, Step, BOp);
923  return true;
924 }
925 
926 /// This function is called when we suspect that the update-chain of a phi node
927 /// (whose symbolic SCEV expression sin \p PhiScev) contains redundant casts,
928 /// that can be ignored. (This can happen when the PSCEV rewriter adds a runtime
929 /// predicate P under which the SCEV expression for the phi can be the
930 /// AddRecurrence \p AR; See createAddRecFromPHIWithCast). We want to find the
931 /// cast instructions that are involved in the update-chain of this induction.
932 /// A caller that adds the required runtime predicate can be free to drop these
933 /// cast instructions, and compute the phi using \p AR (instead of some scev
934 /// expression with casts).
935 ///
936 /// For example, without a predicate the scev expression can take the following
937 /// form:
938 /// (Ext ix (Trunc iy ( Start + i*Step ) to ix) to iy)
939 ///
940 /// It corresponds to the following IR sequence:
941 /// %for.body:
942 /// %x = phi i64 [ 0, %ph ], [ %add, %for.body ]
943 /// %casted_phi = "ExtTrunc i64 %x"
944 /// %add = add i64 %casted_phi, %step
945 ///
946 /// where %x is given in \p PN,
947 /// PSE.getSCEV(%x) is equal to PSE.getSCEV(%casted_phi) under a predicate,
948 /// and the IR sequence that "ExtTrunc i64 %x" represents can take one of
949 /// several forms, for example, such as:
950 /// ExtTrunc1: %casted_phi = and %x, 2^n-1
951 /// or:
952 /// ExtTrunc2: %t = shl %x, m
953 /// %casted_phi = ashr %t, m
954 ///
955 /// If we are able to find such sequence, we return the instructions
956 /// we found, namely %casted_phi and the instructions on its use-def chain up
957 /// to the phi (not including the phi).
959  const SCEVUnknown *PhiScev,
960  const SCEVAddRecExpr *AR,
961  SmallVectorImpl<Instruction *> &CastInsts) {
962 
963  assert(CastInsts.empty() && "CastInsts is expected to be empty.");
964  auto *PN = cast<PHINode>(PhiScev->getValue());
965  assert(PSE.getSCEV(PN) == AR && "Unexpected phi node SCEV expression");
966  const Loop *L = AR->getLoop();
967 
968  // Find any cast instructions that participate in the def-use chain of
969  // PhiScev in the loop.
970  // FORNOW/TODO: We currently expect the def-use chain to include only
971  // two-operand instructions, where one of the operands is an invariant.
972  // createAddRecFromPHIWithCasts() currently does not support anything more
973  // involved than that, so we keep the search simple. This can be
974  // extended/generalized as needed.
975 
976  auto getDef = [&](const Value *Val) -> Value * {
977  const BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Val);
978  if (!BinOp)
979  return nullptr;
980  Value *Op0 = BinOp->getOperand(0);
981  Value *Op1 = BinOp->getOperand(1);
982  Value *Def = nullptr;
983  if (L->isLoopInvariant(Op0))
984  Def = Op1;
985  else if (L->isLoopInvariant(Op1))
986  Def = Op0;
987  return Def;
988  };
989 
990  // Look for the instruction that defines the induction via the
991  // loop backedge.
992  BasicBlock *Latch = L->getLoopLatch();
993  if (!Latch)
994  return false;
995  Value *Val = PN->getIncomingValueForBlock(Latch);
996  if (!Val)
997  return false;
998 
999  // Follow the def-use chain until the induction phi is reached.
1000  // If on the way we encounter a Value that has the same SCEV Expr as the
1001  // phi node, we can consider the instructions we visit from that point
1002  // as part of the cast-sequence that can be ignored.
1003  bool InCastSequence = false;
1004  auto *Inst = dyn_cast<Instruction>(Val);
1005  while (Val != PN) {
1006  // If we encountered a phi node other than PN, or if we left the loop,
1007  // we bail out.
1008  if (!Inst || !L->contains(Inst)) {
1009  return false;
1010  }
1011  auto *AddRec = dyn_cast<SCEVAddRecExpr>(PSE.getSCEV(Val));
1012  if (AddRec && PSE.areAddRecsEqualWithPreds(AddRec, AR))
1013  InCastSequence = true;
1014  if (InCastSequence) {
1015  // Only the last instruction in the cast sequence is expected to have
1016  // uses outside the induction def-use chain.
1017  if (!CastInsts.empty())
1018  if (!Inst->hasOneUse())
1019  return false;
1020  CastInsts.push_back(Inst);
1021  }
1022  Val = getDef(Val);
1023  if (!Val)
1024  return false;
1025  Inst = dyn_cast<Instruction>(Val);
1026  }
1027 
1028  return InCastSequence;
1029 }
1030 
1034  bool Assume) {
1035  Type *PhiTy = Phi->getType();
1036 
1037  // Handle integer and pointer inductions variables.
1038  // Now we handle also FP induction but not trying to make a
1039  // recurrent expression from the PHI node in-place.
1040 
1041  if (!PhiTy->isIntegerTy() && !PhiTy->isPointerTy() &&
1042  !PhiTy->isFloatTy() && !PhiTy->isDoubleTy() && !PhiTy->isHalfTy())
1043  return false;
1044 
1045  if (PhiTy->isFloatingPointTy())
1046  return isFPInductionPHI(Phi, TheLoop, PSE.getSE(), D);
1047 
1048  const SCEV *PhiScev = PSE.getSCEV(Phi);
1049  const auto *AR = dyn_cast<SCEVAddRecExpr>(PhiScev);
1050 
1051  // We need this expression to be an AddRecExpr.
1052  if (Assume && !AR)
1053  AR = PSE.getAsAddRec(Phi);
1054 
1055  if (!AR) {
1056  LLVM_DEBUG(dbgs() << "LV: PHI is not a poly recurrence.\n");
1057  return false;
1058  }
1059 
1060  // Record any Cast instructions that participate in the induction update
1061  const auto *SymbolicPhi = dyn_cast<SCEVUnknown>(PhiScev);
1062  // If we started from an UnknownSCEV, and managed to build an addRecurrence
1063  // only after enabling Assume with PSCEV, this means we may have encountered
1064  // cast instructions that required adding a runtime check in order to
1065  // guarantee the correctness of the AddRecurence respresentation of the
1066  // induction.
1067  if (PhiScev != AR && SymbolicPhi) {
1069  if (getCastsForInductionPHI(PSE, SymbolicPhi, AR, Casts))
1070  return isInductionPHI(Phi, TheLoop, PSE.getSE(), D, AR, &Casts);
1071  }
1072 
1073  return isInductionPHI(Phi, TheLoop, PSE.getSE(), D, AR);
1074 }
1075 
1077  PHINode *Phi, const Loop *TheLoop, ScalarEvolution *SE,
1078  InductionDescriptor &D, const SCEV *Expr,
1079  SmallVectorImpl<Instruction *> *CastsToIgnore) {
1080  Type *PhiTy = Phi->getType();
1081  // We only handle integer and pointer inductions variables.
1082  if (!PhiTy->isIntegerTy() && !PhiTy->isPointerTy())
1083  return false;
1084 
1085  // Check that the PHI is consecutive.
1086  const SCEV *PhiScev = Expr ? Expr : SE->getSCEV(Phi);
1087  const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(PhiScev);
1088 
1089  if (!AR) {
1090  LLVM_DEBUG(dbgs() << "LV: PHI is not a poly recurrence.\n");
1091  return false;
1092  }
1093 
1094  if (AR->getLoop() != TheLoop) {
1095  // FIXME: We should treat this as a uniform. Unfortunately, we
1096  // don't currently know how to handled uniform PHIs.
1097  LLVM_DEBUG(
1098  dbgs() << "LV: PHI is a recurrence with respect to an outer loop.\n");
1099  return false;
1100  }
1101 
1102  Value *StartValue =
1104  const SCEV *Step = AR->getStepRecurrence(*SE);
1105  // Calculate the pointer stride and check if it is consecutive.
1106  // The stride may be a constant or a loop invariant integer value.
1107  const SCEVConstant *ConstStep = dyn_cast<SCEVConstant>(Step);
1108  if (!ConstStep && !SE->isLoopInvariant(Step, TheLoop))
1109  return false;
1110 
1111  if (PhiTy->isIntegerTy()) {
1112  D = InductionDescriptor(StartValue, IK_IntInduction, Step, /*BOp=*/ nullptr,
1113  CastsToIgnore);
1114  return true;
1115  }
1116 
1117  assert(PhiTy->isPointerTy() && "The PHI must be a pointer");
1118  // Pointer induction should be a constant.
1119  if (!ConstStep)
1120  return false;
1121 
1122  ConstantInt *CV = ConstStep->getValue();
1123  Type *PointerElementType = PhiTy->getPointerElementType();
1124  // The pointer stride cannot be determined if the pointer element type is not
1125  // sized.
1126  if (!PointerElementType->isSized())
1127  return false;
1128 
1129  const DataLayout &DL = Phi->getModule()->getDataLayout();
1130  int64_t Size = static_cast<int64_t>(DL.getTypeAllocSize(PointerElementType));
1131  if (!Size)
1132  return false;
1133 
1134  int64_t CVSize = CV->getSExtValue();
1135  if (CVSize % Size)
1136  return false;
1137  auto *StepValue = SE->getConstant(CV->getType(), CVSize / Size,
1138  true /* signed */);
1139  D = InductionDescriptor(StartValue, IK_PtrInduction, StepValue);
1140  return true;
1141 }
1142 
1144  bool PreserveLCSSA) {
1145  bool Changed = false;
1146 
1147  // We re-use a vector for the in-loop predecesosrs.
1148  SmallVector<BasicBlock *, 4> InLoopPredecessors;
1149 
1150  auto RewriteExit = [&](BasicBlock *BB) {
1151  assert(InLoopPredecessors.empty() &&
1152  "Must start with an empty predecessors list!");
1153  auto Cleanup = make_scope_exit([&] { InLoopPredecessors.clear(); });
1154 
1155  // See if there are any non-loop predecessors of this exit block and
1156  // keep track of the in-loop predecessors.
1157  bool IsDedicatedExit = true;
1158  for (auto *PredBB : predecessors(BB))
1159  if (L->contains(PredBB)) {
1160  if (isa<IndirectBrInst>(PredBB->getTerminator()))
1161  // We cannot rewrite exiting edges from an indirectbr.
1162  return false;
1163 
1164  InLoopPredecessors.push_back(PredBB);
1165  } else {
1166  IsDedicatedExit = false;
1167  }
1168 
1169  assert(!InLoopPredecessors.empty() && "Must have *some* loop predecessor!");
1170 
1171  // Nothing to do if this is already a dedicated exit.
1172  if (IsDedicatedExit)
1173  return false;
1174 
1175  auto *NewExitBB = SplitBlockPredecessors(
1176  BB, InLoopPredecessors, ".loopexit", DT, LI, PreserveLCSSA);
1177 
1178  if (!NewExitBB)
1179  LLVM_DEBUG(
1180  dbgs() << "WARNING: Can't create a dedicated exit block for loop: "
1181  << *L << "\n");
1182  else
1183  LLVM_DEBUG(dbgs() << "LoopSimplify: Creating dedicated exit block "
1184  << NewExitBB->getName() << "\n");
1185  return true;
1186  };
1187 
1188  // Walk the exit blocks directly rather than building up a data structure for
1189  // them, but only visit each one once.
1191  for (auto *BB : L->blocks())
1192  for (auto *SuccBB : successors(BB)) {
1193  // We're looking for exit blocks so skip in-loop successors.
1194  if (L->contains(SuccBB))
1195  continue;
1196 
1197  // Visit each exit block exactly once.
1198  if (!Visited.insert(SuccBB).second)
1199  continue;
1200 
1201  Changed |= RewriteExit(SuccBB);
1202  }
1203 
1204  return Changed;
1205 }
1206 
1207 /// Returns the instructions that use values defined in the loop.
1209  SmallVector<Instruction *, 8> UsedOutside;
1210 
1211  for (auto *Block : L->getBlocks())
1212  // FIXME: I believe that this could use copy_if if the Inst reference could
1213  // be adapted into a pointer.
1214  for (auto &Inst : *Block) {
1215  auto Users = Inst.users();
1216  if (any_of(Users, [&](User *U) {
1217  auto *Use = cast<Instruction>(U);
1218  return !L->contains(Use->getParent());
1219  }))
1220  UsedOutside.push_back(&Inst);
1221  }
1222 
1223  return UsedOutside;
1224 }
1225 
1227  // By definition, all loop passes need the LoopInfo analysis and the
1228  // Dominator tree it depends on. Because they all participate in the loop
1229  // pass manager, they must also preserve these.
1234 
1235  // We must also preserve LoopSimplify and LCSSA. We locally access their IDs
1236  // here because users shouldn't directly get them from this header.
1237  extern char &LoopSimplifyID;
1238  extern char &LCSSAID;
1239  AU.addRequiredID(LoopSimplifyID);
1240  AU.addPreservedID(LoopSimplifyID);
1241  AU.addRequiredID(LCSSAID);
1242  AU.addPreservedID(LCSSAID);
1243  // This is used in the LPPassManager to perform LCSSA verification on passes
1244  // which preserve lcssa form
1247 
1248  // Loop passes are designed to run inside of a loop pass manager which means
1249  // that any function analyses they require must be required by the first loop
1250  // pass in the manager (so that it is computed before the loop pass manager
1251  // runs) and preserved by all loop pasess in the manager. To make this
1252  // reasonably robust, the set needed for most loop passes is maintained here.
1253  // If your loop pass requires an analysis not listed here, you will need to
1254  // carefully audit the loop pass manager nesting structure that results.
1262 }
1263 
1264 /// Manually defined generic "LoopPass" dependency initialization. This is used
1265 /// to initialize the exact set of passes from above in \c
1266 /// getLoopAnalysisUsage. It can be used within a loop pass's initialization
1267 /// with:
1268 ///
1269 /// INITIALIZE_PASS_DEPENDENCY(LoopPass)
1270 ///
1271 /// As-if "LoopPass" were a pass.
1275  INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
1276  INITIALIZE_PASS_DEPENDENCY(LCSSAWrapperPass)
1282 }
1283 
1284 /// Find string metadata for loop
1285 ///
1286 /// If it has a value (e.g. {"llvm.distribute", 1} return the value as an
1287 /// operand or null otherwise. If the string metadata is not found return
1288 /// Optional's not-a-value.
1290  StringRef Name) {
1291  MDNode *LoopID = TheLoop->getLoopID();
1292  // Return none if LoopID is false.
1293  if (!LoopID)
1294  return None;
1295 
1296  // First operand should refer to the loop id itself.
1297  assert(LoopID->getNumOperands() > 0 && "requires at least one operand");
1298  assert(LoopID->getOperand(0) == LoopID && "invalid loop id");
1299 
1300  // Iterate over LoopID operands and look for MDString Metadata
1301  for (unsigned i = 1, e = LoopID->getNumOperands(); i < e; ++i) {
1302  MDNode *MD = dyn_cast<MDNode>(LoopID->getOperand(i));
1303  if (!MD)
1304  continue;
1305  MDString *S = dyn_cast<MDString>(MD->getOperand(0));
1306  if (!S)
1307  continue;
1308  // Return true if MDString holds expected MetaData.
1309  if (Name.equals(S->getString()))
1310  switch (MD->getNumOperands()) {
1311  case 1:
1312  return nullptr;
1313  case 2:
1314  return &MD->getOperand(1);
1315  default:
1316  llvm_unreachable("loop metadata has 0 or 1 operand");
1317  }
1318  }
1319  return None;
1320 }
1321 
1322 /// Does a BFS from a given node to all of its children inside a given loop.
1323 /// The returned vector of nodes includes the starting point.
1327  auto AddRegionToWorklist = [&](DomTreeNode *DTN) {
1328  // Only include subregions in the top level loop.
1329  BasicBlock *BB = DTN->getBlock();
1330  if (CurLoop->contains(BB))
1331  Worklist.push_back(DTN);
1332  };
1333 
1334  AddRegionToWorklist(N);
1335 
1336  for (size_t I = 0; I < Worklist.size(); I++)
1337  for (DomTreeNode *Child : Worklist[I]->getChildren())
1338  AddRegionToWorklist(Child);
1339 
1340  return Worklist;
1341 }
1342 
1343 void llvm::deleteDeadLoop(Loop *L, DominatorTree *DT = nullptr,
1344  ScalarEvolution *SE = nullptr,
1345  LoopInfo *LI = nullptr) {
1346  assert((!DT || L->isLCSSAForm(*DT)) && "Expected LCSSA!");
1347  auto *Preheader = L->getLoopPreheader();
1348  assert(Preheader && "Preheader should exist!");
1349 
1350  // Now that we know the removal is safe, remove the loop by changing the
1351  // branch from the preheader to go to the single exit block.
1352  //
1353  // Because we're deleting a large chunk of code at once, the sequence in which
1354  // we remove things is very important to avoid invalidation issues.
1355 
1356  // Tell ScalarEvolution that the loop is deleted. Do this before
1357  // deleting the loop so that ScalarEvolution can look at the loop
1358  // to determine what it needs to clean up.
1359  if (SE)
1360  SE->forgetLoop(L);
1361 
1362  auto *ExitBlock = L->getUniqueExitBlock();
1363  assert(ExitBlock && "Should have a unique exit block!");
1364  assert(L->hasDedicatedExits() && "Loop should have dedicated exits!");
1365 
1366  auto *OldBr = dyn_cast<BranchInst>(Preheader->getTerminator());
1367  assert(OldBr && "Preheader must end with a branch");
1368  assert(OldBr->isUnconditional() && "Preheader must have a single successor");
1369  // Connect the preheader to the exit block. Keep the old edge to the header
1370  // around to perform the dominator tree update in two separate steps
1371  // -- #1 insertion of the edge preheader -> exit and #2 deletion of the edge
1372  // preheader -> header.
1373  //
1374  //
1375  // 0. Preheader 1. Preheader 2. Preheader
1376  // | | | |
1377  // V | V |
1378  // Header <--\ | Header <--\ | Header <--\
1379  // | | | | | | | | | | |
1380  // | V | | | V | | | V |
1381  // | Body --/ | | Body --/ | | Body --/
1382  // V V V V V
1383  // Exit Exit Exit
1384  //
1385  // By doing this is two separate steps we can perform the dominator tree
1386  // update without using the batch update API.
1387  //
1388  // Even when the loop is never executed, we cannot remove the edge from the
1389  // source block to the exit block. Consider the case where the unexecuted loop
1390  // branches back to an outer loop. If we deleted the loop and removed the edge
1391  // coming to this inner loop, this will break the outer loop structure (by
1392  // deleting the backedge of the outer loop). If the outer loop is indeed a
1393  // non-loop, it will be deleted in a future iteration of loop deletion pass.
1394  IRBuilder<> Builder(OldBr);
1395  Builder.CreateCondBr(Builder.getFalse(), L->getHeader(), ExitBlock);
1396  // Remove the old branch. The conditional branch becomes a new terminator.
1397  OldBr->eraseFromParent();
1398 
1399  // Rewrite phis in the exit block to get their inputs from the Preheader
1400  // instead of the exiting block.
1401  for (PHINode &P : ExitBlock->phis()) {
1402  // Set the zero'th element of Phi to be from the preheader and remove all
1403  // other incoming values. Given the loop has dedicated exits, all other
1404  // incoming values must be from the exiting blocks.
1405  int PredIndex = 0;
1406  P.setIncomingBlock(PredIndex, Preheader);
1407  // Removes all incoming values from all other exiting blocks (including
1408  // duplicate values from an exiting block).
1409  // Nuke all entries except the zero'th entry which is the preheader entry.
1410  // NOTE! We need to remove Incoming Values in the reverse order as done
1411  // below, to keep the indices valid for deletion (removeIncomingValues
1412  // updates getNumIncomingValues and shifts all values down into the operand
1413  // being deleted).
1414  for (unsigned i = 0, e = P.getNumIncomingValues() - 1; i != e; ++i)
1415  P.removeIncomingValue(e - i, false);
1416 
1417  assert((P.getNumIncomingValues() == 1 &&
1418  P.getIncomingBlock(PredIndex) == Preheader) &&
1419  "Should have exactly one value and that's from the preheader!");
1420  }
1421 
1422  // Disconnect the loop body by branching directly to its exit.
1423  Builder.SetInsertPoint(Preheader->getTerminator());
1424  Builder.CreateBr(ExitBlock);
1425  // Remove the old branch.
1426  Preheader->getTerminator()->eraseFromParent();
1427 
1428  if (DT) {
1429  // Update the dominator tree by informing it about the new edge from the
1430  // preheader to the exit.
1431  DT->insertEdge(Preheader, ExitBlock);
1432  // Inform the dominator tree about the removed edge.
1433  DT->deleteEdge(Preheader, L->getHeader());
1434  }
1435 
1436  // Given LCSSA form is satisfied, we should not have users of instructions
1437  // within the dead loop outside of the loop. However, LCSSA doesn't take
1438  // unreachable uses into account. We handle them here.
1439  // We could do it after drop all references (in this case all users in the
1440  // loop will be already eliminated and we have less work to do but according
1441  // to API doc of User::dropAllReferences only valid operation after dropping
1442  // references, is deletion. So let's substitute all usages of
1443  // instruction from the loop with undef value of corresponding type first.
1444  for (auto *Block : L->blocks())
1445  for (Instruction &I : *Block) {
1446  auto *Undef = UndefValue::get(I.getType());
1447  for (Value::use_iterator UI = I.use_begin(), E = I.use_end(); UI != E;) {
1448  Use &U = *UI;
1449  ++UI;
1450  if (auto *Usr = dyn_cast<Instruction>(U.getUser()))
1451  if (L->contains(Usr->getParent()))
1452  continue;
1453  // If we have a DT then we can check that uses outside a loop only in
1454  // unreachable block.
1455  if (DT)
1456  assert(!DT->isReachableFromEntry(U) &&
1457  "Unexpected user in reachable block");
1458  U.set(Undef);
1459  }
1460  }
1461 
1462  // Remove the block from the reference counting scheme, so that we can
1463  // delete it freely later.
1464  for (auto *Block : L->blocks())
1465  Block->dropAllReferences();
1466 
1467  if (LI) {
1468  // Erase the instructions and the blocks without having to worry
1469  // about ordering because we already dropped the references.
1470  // NOTE: This iteration is safe because erasing the block does not remove
1471  // its entry from the loop's block list. We do that in the next section.
1472  for (Loop::block_iterator LpI = L->block_begin(), LpE = L->block_end();
1473  LpI != LpE; ++LpI)
1474  (*LpI)->eraseFromParent();
1475 
1476  // Finally, the blocks from loopinfo. This has to happen late because
1477  // otherwise our loop iterators won't work.
1478 
1480  blocks.insert(L->block_begin(), L->block_end());
1481  for (BasicBlock *BB : blocks)
1482  LI->removeBlock(BB);
1483 
1484  // The last step is to update LoopInfo now that we've eliminated this loop.
1485  LI->erase(L);
1486  }
1487 }
1488 
1490  // Only support loops with a unique exiting block, and a latch.
1491  if (!L->getExitingBlock())
1492  return None;
1493 
1494  // Get the branch weights for the loop's backedge.
1495  BranchInst *LatchBR =
1497  if (!LatchBR || LatchBR->getNumSuccessors() != 2)
1498  return None;
1499 
1500  assert((LatchBR->getSuccessor(0) == L->getHeader() ||
1501  LatchBR->getSuccessor(1) == L->getHeader()) &&
1502  "At least one edge out of the latch must go to the header");
1503 
1504  // To estimate the number of times the loop body was executed, we want to
1505  // know the number of times the backedge was taken, vs. the number of times
1506  // we exited the loop.
1507  uint64_t TrueVal, FalseVal;
1508  if (!LatchBR->extractProfMetadata(TrueVal, FalseVal))
1509  return None;
1510 
1511  if (!TrueVal || !FalseVal)
1512  return 0;
1513 
1514  // Divide the count of the backedge by the count of the edge exiting the loop,
1515  // rounding to nearest.
1516  if (LatchBR->getSuccessor(0) == L->getHeader())
1517  return (TrueVal + (FalseVal / 2)) / FalseVal;
1518  else
1519  return (FalseVal + (TrueVal / 2)) / TrueVal;
1520 }
1521 
1522 /// Adds a 'fast' flag to floating point operations.
1524  if (isa<FPMathOperator>(V)) {
1525  FastMathFlags Flags;
1526  Flags.setFast();
1527  cast<Instruction>(V)->setFastMathFlags(Flags);
1528  }
1529  return V;
1530 }
1531 
1532 // Helper to generate an ordered reduction.
1533 Value *
1535  unsigned Op,
1537  ArrayRef<Value *> RedOps) {
1538  unsigned VF = Src->getType()->getVectorNumElements();
1539 
1540  // Extract and apply reduction ops in ascending order:
1541  // e.g. ((((Acc + Scl[0]) + Scl[1]) + Scl[2]) + ) ... + Scl[VF-1]
1542  Value *Result = Acc;
1543  for (unsigned ExtractIdx = 0; ExtractIdx != VF; ++ExtractIdx) {
1544  Value *Ext =
1545  Builder.CreateExtractElement(Src, Builder.getInt32(ExtractIdx));
1546 
1547  if (Op != Instruction::ICmp && Op != Instruction::FCmp) {
1548  Result = Builder.CreateBinOp((Instruction::BinaryOps)Op, Result, Ext,
1549  "bin.rdx");
1550  } else {
1551  assert(MinMaxKind != RecurrenceDescriptor::MRK_Invalid &&
1552  "Invalid min/max");
1553  Result = RecurrenceDescriptor::createMinMaxOp(Builder, MinMaxKind, Result,
1554  Ext);
1555  }
1556 
1557  if (!RedOps.empty())
1558  propagateIRFlags(Result, RedOps);
1559  }
1560 
1561  return Result;
1562 }
1563 
1564 // Helper to generate a log2 shuffle reduction.
1565 Value *
1568  ArrayRef<Value *> RedOps) {
1569  unsigned VF = Src->getType()->getVectorNumElements();
1570  // VF is a power of 2 so we can emit the reduction using log2(VF) shuffles
1571  // and vector ops, reducing the set of values being computed by half each
1572  // round.
1573  assert(isPowerOf2_32(VF) &&
1574  "Reduction emission only supported for pow2 vectors!");
1575  Value *TmpVec = Src;
1576  SmallVector<Constant *, 32> ShuffleMask(VF, nullptr);
1577  for (unsigned i = VF; i != 1; i >>= 1) {
1578  // Move the upper half of the vector to the lower half.
1579  for (unsigned j = 0; j != i / 2; ++j)
1580  ShuffleMask[j] = Builder.getInt32(i / 2 + j);
1581 
1582  // Fill the rest of the mask with undef.
1583  std::fill(&ShuffleMask[i / 2], ShuffleMask.end(),
1584  UndefValue::get(Builder.getInt32Ty()));
1585 
1586  Value *Shuf = Builder.CreateShuffleVector(
1587  TmpVec, UndefValue::get(TmpVec->getType()),
1588  ConstantVector::get(ShuffleMask), "rdx.shuf");
1589 
1590  if (Op != Instruction::ICmp && Op != Instruction::FCmp) {
1591  // Floating point operations had to be 'fast' to enable the reduction.
1592  TmpVec = addFastMathFlag(Builder.CreateBinOp((Instruction::BinaryOps)Op,
1593  TmpVec, Shuf, "bin.rdx"));
1594  } else {
1595  assert(MinMaxKind != RecurrenceDescriptor::MRK_Invalid &&
1596  "Invalid min/max");
1597  TmpVec = RecurrenceDescriptor::createMinMaxOp(Builder, MinMaxKind, TmpVec,
1598  Shuf);
1599  }
1600  if (!RedOps.empty())
1601  propagateIRFlags(TmpVec, RedOps);
1602  }
1603  // The result is in the first element of the vector.
1604  return Builder.CreateExtractElement(TmpVec, Builder.getInt32(0));
1605 }
1606 
1607 /// Create a simple vector reduction specified by an opcode and some
1608 /// flags (if generating min/max reductions).
1610  IRBuilder<> &Builder, const TargetTransformInfo *TTI, unsigned Opcode,
1612  ArrayRef<Value *> RedOps) {
1613  assert(isa<VectorType>(Src->getType()) && "Type must be a vector");
1614 
1615  Value *ScalarUdf = UndefValue::get(Src->getType()->getVectorElementType());
1616  std::function<Value*()> BuildFunc;
1617  using RD = RecurrenceDescriptor;
1618  RD::MinMaxRecurrenceKind MinMaxKind = RD::MRK_Invalid;
1619  // TODO: Support creating ordered reductions.
1620  FastMathFlags FMFFast;
1621  FMFFast.setFast();
1622 
1623  switch (Opcode) {
1624  case Instruction::Add:
1625  BuildFunc = [&]() { return Builder.CreateAddReduce(Src); };
1626  break;
1627  case Instruction::Mul:
1628  BuildFunc = [&]() { return Builder.CreateMulReduce(Src); };
1629  break;
1630  case Instruction::And:
1631  BuildFunc = [&]() { return Builder.CreateAndReduce(Src); };
1632  break;
1633  case Instruction::Or:
1634  BuildFunc = [&]() { return Builder.CreateOrReduce(Src); };
1635  break;
1636  case Instruction::Xor:
1637  BuildFunc = [&]() { return Builder.CreateXorReduce(Src); };
1638  break;
1639  case Instruction::FAdd:
1640  BuildFunc = [&]() {
1641  auto Rdx = Builder.CreateFAddReduce(ScalarUdf, Src);
1642  cast<CallInst>(Rdx)->setFastMathFlags(FMFFast);
1643  return Rdx;
1644  };
1645  break;
1646  case Instruction::FMul:
1647  BuildFunc = [&]() {
1648  auto Rdx = Builder.CreateFMulReduce(ScalarUdf, Src);
1649  cast<CallInst>(Rdx)->setFastMathFlags(FMFFast);
1650  return Rdx;
1651  };
1652  break;
1653  case Instruction::ICmp:
1654  if (Flags.IsMaxOp) {
1655  MinMaxKind = Flags.IsSigned ? RD::MRK_SIntMax : RD::MRK_UIntMax;
1656  BuildFunc = [&]() {
1657  return Builder.CreateIntMaxReduce(Src, Flags.IsSigned);
1658  };
1659  } else {
1660  MinMaxKind = Flags.IsSigned ? RD::MRK_SIntMin : RD::MRK_UIntMin;
1661  BuildFunc = [&]() {
1662  return Builder.CreateIntMinReduce(Src, Flags.IsSigned);
1663  };
1664  }
1665  break;
1666  case Instruction::FCmp:
1667  if (Flags.IsMaxOp) {
1668  MinMaxKind = RD::MRK_FloatMax;
1669  BuildFunc = [&]() { return Builder.CreateFPMaxReduce(Src, Flags.NoNaN); };
1670  } else {
1671  MinMaxKind = RD::MRK_FloatMin;
1672  BuildFunc = [&]() { return Builder.CreateFPMinReduce(Src, Flags.NoNaN); };
1673  }
1674  break;
1675  default:
1676  llvm_unreachable("Unhandled opcode");
1677  break;
1678  }
1679  if (TTI->useReductionIntrinsic(Opcode, Src->getType(), Flags))
1680  return BuildFunc();
1681  return getShuffleReduction(Builder, Src, Opcode, MinMaxKind, RedOps);
1682 }
1683 
1684 /// Create a vector reduction using a given recurrence descriptor.
1686  const TargetTransformInfo *TTI,
1687  RecurrenceDescriptor &Desc, Value *Src,
1688  bool NoNaN) {
1689  // TODO: Support in-order reductions based on the recurrence descriptor.
1690  using RD = RecurrenceDescriptor;
1691  RD::RecurrenceKind RecKind = Desc.getRecurrenceKind();
1693  Flags.NoNaN = NoNaN;
1694  switch (RecKind) {
1695  case RD::RK_FloatAdd:
1696  return createSimpleTargetReduction(B, TTI, Instruction::FAdd, Src, Flags);
1697  case RD::RK_FloatMult:
1698  return createSimpleTargetReduction(B, TTI, Instruction::FMul, Src, Flags);
1699  case RD::RK_IntegerAdd:
1700  return createSimpleTargetReduction(B, TTI, Instruction::Add, Src, Flags);
1701  case RD::RK_IntegerMult:
1702  return createSimpleTargetReduction(B, TTI, Instruction::Mul, Src, Flags);
1703  case RD::RK_IntegerAnd:
1704  return createSimpleTargetReduction(B, TTI, Instruction::And, Src, Flags);
1705  case RD::RK_IntegerOr:
1706  return createSimpleTargetReduction(B, TTI, Instruction::Or, Src, Flags);
1707  case RD::RK_IntegerXor:
1708  return createSimpleTargetReduction(B, TTI, Instruction::Xor, Src, Flags);
1709  case RD::RK_IntegerMinMax: {
1710  RD::MinMaxRecurrenceKind MMKind = Desc.getMinMaxRecurrenceKind();
1711  Flags.IsMaxOp = (MMKind == RD::MRK_SIntMax || MMKind == RD::MRK_UIntMax);
1712  Flags.IsSigned = (MMKind == RD::MRK_SIntMax || MMKind == RD::MRK_SIntMin);
1713  return createSimpleTargetReduction(B, TTI, Instruction::ICmp, Src, Flags);
1714  }
1715  case RD::RK_FloatMinMax: {
1716  Flags.IsMaxOp = Desc.getMinMaxRecurrenceKind() == RD::MRK_FloatMax;
1717  return createSimpleTargetReduction(B, TTI, Instruction::FCmp, Src, Flags);
1718  }
1719  default:
1720  llvm_unreachable("Unhandled RecKind");
1721  }
1722 }
1723 
1725  auto *VecOp = dyn_cast<Instruction>(I);
1726  if (!VecOp)
1727  return;
1728  auto *Intersection = (OpValue == nullptr) ? dyn_cast<Instruction>(VL[0])
1729  : dyn_cast<Instruction>(OpValue);
1730  if (!Intersection)
1731  return;
1732  const unsigned Opcode = Intersection->getOpcode();
1733  VecOp->copyIRFlags(Intersection);
1734  for (auto *V : VL) {
1735  auto *Instr = dyn_cast<Instruction>(V);
1736  if (!Instr)
1737  continue;
1738  if (OpValue == nullptr || Opcode == Instr->getOpcode())
1739  VecOp->andIRFlags(V);
1740  }
1741 }
Legacy wrapper pass to provide the GlobalsAAResult object.
MaxMin_match< ICmpInst, LHS, RHS, umin_pred_ty > m_UMin(const LHS &L, const RHS &R)
Type * getVectorElementType() const
Definition: Type.h:368
const NoneType None
Definition: None.h:24
static bool isArithmeticRecurrenceKind(RecurrenceKind Kind)
Returns true if the recurrence kind is an arithmetic kind.
Definition: LoopUtils.cpp:71
IntegerType * getType() const
getType - Specialize the getType() method to always return an IntegerType, which reduces the amount o...
Definition: Constants.h:172
A parsed version of the target data layout string in and methods for querying it. ...
Definition: DataLayout.h:111
class_match< Value > m_Value()
Match an arbitrary value and ignore it.
Definition: PatternMatch.h:72
Value * CreateICmp(CmpInst::Predicate P, Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1846
AnalysisUsage & addPreserved()
Add the specified Pass class to the set of analyses preserved by this pass.
BlockT * getLoopLatch() const
If there is a single latch block for this loop, return it.
Definition: LoopInfoImpl.h:157
Value * CreateBinOp(Instruction::BinaryOps Opc, Value *LHS, Value *RHS, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:1246
static bool isFPInductionPHI(PHINode *Phi, const Loop *L, ScalarEvolution *SE, InductionDescriptor &D)
Returns true if Phi is a floating point induction in the loop L.
Definition: LoopUtils.cpp:873
void setFast(bool B=true)
Definition: Operator.h:231
InductionDescriptor()=default
Default constructor - creates an invalid induction.
const SCEV * getConstant(ConstantInt *V)
static Instruction * lookThroughAnd(PHINode *Phi, Type *&RT, SmallPtrSetImpl< Instruction *> &Visited, SmallPtrSetImpl< Instruction *> &CI)
Determines if Phi may have been type-promoted.
Definition: LoopUtils.cpp:88
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
BinaryOps getOpcode() const
Definition: InstrTypes.h:555
This is the interface for a simple mod/ref and alias analysis over globals.
static bool isInductionPHI(PHINode *Phi, const Loop *L, ScalarEvolution *SE, InductionDescriptor &D, const SCEV *Expr=nullptr, SmallVectorImpl< Instruction *> *CastsToIgnore=nullptr)
Returns true if Phi is an induction in the loop L.
Definition: LoopUtils.cpp:1076
bool isSized(SmallPtrSetImpl< Type *> *Visited=nullptr) const
Return true if it makes sense to take the size of this type.
Definition: Type.h:262
LLVM_ATTRIBUTE_ALWAYS_INLINE size_type size() const
Definition: SmallVector.h:137
int getConsecutiveDirection() const
Get the consecutive direction.
Definition: LoopUtils.cpp:792
ConstantInt * getConstIntStepValue() const
Definition: LoopUtils.cpp:799
bool isLCSSAForm(DominatorTree &DT) const
Return true if the Loop is in LCSSA form.
Definition: LoopInfo.cpp:176
static bool AddReductionVar(PHINode *Phi, RecurrenceKind Kind, Loop *TheLoop, bool HasFunNoNaNAttr, RecurrenceDescriptor &RedDes, DemandedBits *DB=nullptr, AssumptionCache *AC=nullptr, DominatorTree *DT=nullptr)
Returns true if Phi is a reduction of type Kind and adds it to the RecurrenceDescriptor.
Definition: LoopUtils.cpp:191
The main scalar evolution driver.
A global registry used in conjunction with static constructors to make pluggable components (like tar...
Definition: Registry.h:45
BlockT * getLoopPreheader() const
If there is a preheader for this loop, return it.
Definition: LoopInfoImpl.h:106
unsigned less than
Definition: InstrTypes.h:910
A cache of @llvm.assume calls within a function.
BasicBlock * getUniqueExitBlock() const
If getUniqueExitBlocks would return exactly one block, return that block.
Definition: LoopInfo.cpp:436
0 1 0 0 True if ordered and less than
Definition: InstrTypes.h:891
Value * createSimpleTargetReduction(IRBuilder<> &B, const TargetTransformInfo *TTI, unsigned Opcode, Value *Src, TargetTransformInfo::ReductionFlags Flags=TargetTransformInfo::ReductionFlags(), ArrayRef< Value *> RedOps=None)
Create a target reduction of the given vector.
Definition: LoopUtils.cpp:1609
LLVM_NODISCARD detail::scope_exit< typename std::decay< Callable >::type > make_scope_exit(Callable &&F)
Definition: ScopeExit.h:59
LLVMContext & getContext() const
All values hold a context through their type.
Definition: Value.cpp:713
bool isLoopInvariant(const SCEV *S, const Loop *L)
Return true if the value of the given SCEV is unchanging in the specified loop.
BasicBlock * getSuccessor(unsigned i) const
MinMaxRecurrenceKind getMinMaxRecurrenceKind()
Definition: LoopUtils.h:200
Metadata node.
Definition: Metadata.h:862
F(f)
const MDOperand & getOperand(unsigned I) const
Definition: Metadata.h:1067
Value * getShuffleReduction(IRBuilder<> &Builder, Value *Src, unsigned Op, RecurrenceDescriptor::MinMaxRecurrenceKind MinMaxKind=RecurrenceDescriptor::MRK_Invalid, ArrayRef< Value *> RedOps=None)
Generates a vector reduction using shufflevectors to reduce the value.
Definition: LoopUtils.cpp:1566
MaxMin_match< FCmpInst, LHS, RHS, ufmax_pred_ty > m_UnordFMax(const LHS &L, const RHS &R)
Match an &#39;unordered&#39; floating point maximum function.
iv Induction Variable Users
Definition: IVUsers.cpp:52
static InstDesc isRecurrenceInstr(Instruction *I, RecurrenceKind Kind, InstDesc &Prev, bool HasFunNoNaNAttr)
Returns a struct describing if the instruction &#39;I&#39; can be a recurrence variable of type &#39;Kind&#39;...
Definition: LoopUtils.cpp:495
op_iterator op_begin()
Definition: User.h:230
static bool hasMultipleUsesOf(Instruction *I, SmallPtrSetImpl< Instruction *> &Insts)
Returns true if instruction I has multiple uses in Insts.
Definition: LoopUtils.cpp:533
IntegerType * getInt32Ty()
Fetch the type representing a 32-bit integer.
Definition: IRBuilder.h:347
bool match(Val *V, const Pattern &P)
Definition: PatternMatch.h:49
AnalysisUsage & addRequired()
#define INITIALIZE_PASS_DEPENDENCY(depName)
Definition: PassSupport.h:51
This is the interface for a SCEV-based alias analysis.
void initializeLoopPassPass(PassRegistry &)
Manually defined generic "LoopPass" dependency initialization.
Definition: LoopUtils.cpp:1272
This class represents the LLVM &#39;select&#39; instruction.
Type * getPointerElementType() const
Definition: Type.h:373
const DataLayout & getDataLayout() const
Get the data layout for the module&#39;s target platform.
Definition: Module.cpp:361
int getBasicBlockIndex(const BasicBlock *BB) const
Return the first index of the specified basic block in the value list for this PHI.
bool isFloatingPointTy() const
Return true if this is one of the six floating-point types.
Definition: Type.h:162
unsigned getNumSuccessors() const
CallInst * CreateFAddReduce(Value *Acc, Value *Src)
Create a vector fadd reduction intrinsic of the source vector.
Definition: IRBuilder.cpp:321
A Use represents the edge between a Value definition and its users.
Definition: Use.h:56
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APFloat.h:42
bool isIntegerTy() const
True if this is an instance of IntegerType.
Definition: Type.h:197
This provides a uniform API for creating instructions and inserting them into a basic block: either a...
Definition: IRBuilder.h:731
static bool areAllUsesIn(Instruction *I, SmallPtrSetImpl< Instruction *> &Set)
Returns true if all uses of the instruction I is within the Set.
Definition: LoopUtils.cpp:44
static InstDesc isMinMaxSelectCmpPattern(Instruction *I, InstDesc &Prev)
Returns a struct describing if the instruction if the instruction is a Select(ICmp(X, Y), X, Y) instruction pattern corresponding to a min(X, Y) or max(X, Y).
Definition: LoopUtils.cpp:446
Value * CreateAdd(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:962
MaxMin_match< FCmpInst, LHS, RHS, ufmin_pred_ty > m_UnordFMin(const LHS &L, const RHS &R)
Match an &#39;unordered&#39; floating point minimum function.
Contains a collection of routines for determining if a given instruction is guaranteed to execute if ...
SmallVector< Instruction *, 8 > findDefsUsedOutsideOfLoop(Loop *L)
Returns the instructions that use values defined in the loop.
Definition: LoopUtils.cpp:1208
BlockT * getHeader() const
Definition: LoopInfo.h:100
CallInst * CreateFPMinReduce(Value *Src, bool NoNaN=false)
Create a vector float min reduction intrinsic of the source vector.
Definition: IRBuilder.cpp:389
void deleteDeadLoop(Loop *L, DominatorTree *DT, ScalarEvolution *SE, LoopInfo *LI)
This function deletes dead loops.
Definition: LoopUtils.cpp:1343
bool hasDedicatedExits() const
Return true if no exit block for the loop has a predecessor that is outside the loop.
Definition: LoopInfo.cpp:381
Value * getOrderedReduction(IRBuilder<> &Builder, Value *Acc, Value *Src, unsigned Op, RecurrenceDescriptor::MinMaxRecurrenceKind MinMaxKind=RecurrenceDescriptor::MRK_Invalid, ArrayRef< Value *> RedOps=None)
Generates an ordered vector reduction using extracts to reduce the value.
Definition: LoopUtils.cpp:1534
ConstantInt * getValue() const
bool isOne() const
This is just a convenience method to make client code smaller for a common case.
Definition: Constants.h:201
User * getUser() const LLVM_READONLY
Returns the User that contains this Use.
Definition: Use.cpp:41
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:245
This node represents a polynomial recurrence on the trip count of the specified loop.
This instruction compares its operands according to the predicate given to the constructor.
void andIRFlags(const Value *V)
Logical &#39;and&#39; of any supported wrapping, exact, and fast-math flags of V and this instruction...
MaxMin_match< FCmpInst, LHS, RHS, ofmin_pred_ty > m_OrdFMin(const LHS &L, const RHS &R)
Match an &#39;ordered&#39; floating point minimum function.
MaxMin_match< ICmpInst, LHS, RHS, smin_pred_ty > m_SMin(const LHS &L, const RHS &R)
const SCEVAddRecExpr * getAsAddRec(Value *V)
Attempts to produce an AddRecExpr for V by adding additional SCEV predicates.
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:33
unsigned getOpcode() const
Returns a member of one of the enums like Instruction::Add.
Definition: Instruction.h:126
AnalysisUsage & addPreservedID(const void *ID)
Value * CreateSub(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:979
bool isMinusOne() const
This function will return true iff every bit in this constant is set to true.
Definition: Constants.h:209
This POD struct holds information about a potential recurrence operation.
Definition: LoopUtils.h:102
const SCEV * getStepRecurrence(ScalarEvolution &SE) const
Constructs and returns the recurrence indicating how much this expression steps by.
Concrete subclass of DominatorTreeBase that is used to compute a normal dominator tree...
Definition: Dominators.h:142
Value * getOperand(unsigned i) const
Definition: User.h:170
const SCEV * getSCEV(Value *V)
Returns the SCEV expression of V, in the context of the current SCEV predicate.
use_iterator_impl< Use > use_iterator
Definition: Value.h:331
static void collectCastsToIgnore(Loop *TheLoop, Instruction *Exit, Type *RecurrenceType, SmallPtrSetImpl< Instruction *> &Casts)
Collect cast instructions that can be ignored in the vectorizer&#39;s cost model, given a reduction exit ...
Definition: LoopUtils.cpp:162
CallInst * CreateXorReduce(Value *Src)
Create a vector int XOR reduction intrinsic of the source vector.
Definition: IRBuilder.cpp:361
bool isNegative() const
Returns true if this value is known to be negative.
Definition: KnownBits.h:96
StringRef getString() const
Definition: Metadata.cpp:464
static bool getCastsForInductionPHI(PredicatedScalarEvolution &PSE, const SCEVUnknown *PhiScev, const SCEVAddRecExpr *AR, SmallVectorImpl< Instruction *> &CastInsts)
This function is called when we suspect that the update-chain of a phi node (whose symbolic SCEV expr...
Definition: LoopUtils.cpp:958
Value * CreateFCmp(CmpInst::Predicate P, Value *LHS, Value *RHS, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:1854
bool isFloatTy() const
Return true if this is &#39;float&#39;, a 32-bit IEEE fp type.
Definition: Type.h:147
#define P(N)
This means that we are dealing with an entirely unknown SCEV value, and only represent it as its LLVM...
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
Value * CreateFMul(Value *L, Value *R, const Twine &Name="", MDNode *FPMD=nullptr)
Definition: IRBuilder.h:1195
MaxMin_match< ICmpInst, LHS, RHS, umax_pred_ty > m_UMax(const LHS &L, const RHS &R)
apint_match m_APInt(const APInt *&Res)
Match a ConstantInt or splatted ConstantVector, binding the specified pointer to the contained APInt...
Definition: PatternMatch.h:177
void set(Value *Val)
Definition: Value.h:670
constexpr bool isPowerOf2_32(uint32_t Value)
Return true if the argument is a power of two > 0.
Definition: MathExtras.h:421
LLVM Basic Block Representation.
Definition: BasicBlock.h:59
Flags describing the kind of vector reduction.
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
Conditional or Unconditional Branch instruction.
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
This is an important base class in LLVM.
Definition: Constant.h:42
LLVM_ATTRIBUTE_ALWAYS_INLINE iterator begin()
Definition: SmallVector.h:117
Value * getIncomingValueForBlock(const BasicBlock *BB) const
Value * CreateSelect(Value *C, Value *True, Value *False, const Twine &Name="", Instruction *MDFrom=nullptr)
Definition: IRBuilder.h:1901
bool isPointerTy() const
True if this is an instance of PointerType.
Definition: Type.h:221
BinaryOp_match< LHS, RHS, Instruction::And, true > m_c_And(const LHS &L, const RHS &R)
Matches an And with LHS and RHS in either order.
char & LCSSAID
Definition: LCSSA.cpp:423
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:371
const SCEV * getAddExpr(SmallVectorImpl< const SCEV *> &Ops, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)
Get a canonical add expression, or something simpler if possible.
Represent the analysis usage information of a pass.
constexpr bool isPowerOf2_64(uint64_t Value)
Return true if the argument is a power of two > 0 (64 bit edition.)
Definition: MathExtras.h:426
op_iterator op_end()
Definition: User.h:232
bool isFast() const
Determine whether all fast-math-flags are set.
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:915
bool isHalfTy() const
Return true if this is &#39;half&#39;, a 16-bit IEEE fp type.
Definition: Type.h:144
Predicate
This enumeration lists the possible predicates for CmpInst subclasses.
Definition: InstrTypes.h:885
Value * expandCodeFor(const SCEV *SH, Type *Ty, Instruction *I)
Insert code to directly compute the specified SCEV expression into the program.
op_range operands()
Definition: User.h:238
BasicBlock * SplitBlockPredecessors(BasicBlock *BB, ArrayRef< BasicBlock *> Preds, const char *Suffix, DominatorTree *DT=nullptr, LoopInfo *LI=nullptr, bool PreserveLCSSA=false)
This method introduces at least one new basic block into the function and moves some of the predecess...
bool areAddRecsEqualWithPreds(const SCEVAddRecExpr *AR1, const SCEVAddRecExpr *AR2) const
Check if AR1 and AR2 are equal, while taking into account Equal predicates in Preds.
size_type count(ConstPtrType Ptr) const
count - Return 1 if the specified pointer is in the set, 0 otherwise.
Definition: SmallPtrSet.h:382
Optional< unsigned > getLoopEstimatedTripCount(Loop *L)
Get a loop&#39;s estimated trip count based on branch weight metadata.
Definition: LoopUtils.cpp:1489
static bool isReductionPHI(PHINode *Phi, Loop *TheLoop, RecurrenceDescriptor &RedDes, DemandedBits *DB=nullptr, AssumptionCache *AC=nullptr, DominatorTree *DT=nullptr)
Returns true if Phi is a reduction in TheLoop.
Definition: LoopUtils.cpp:546
Value * CreateExtractElement(Value *Vec, Value *Idx, const Twine &Name="")
Definition: IRBuilder.h:1921
static UndefValue * get(Type *T)
Static factory methods - Return an &#39;undef&#39; object of the specified type.
Definition: Constants.cpp:1382
uint64_t NextPowerOf2(uint64_t A)
Returns the next power of two (in 64-bits) that is strictly greater than A.
Definition: MathExtras.h:632
ScalarEvolution * getSE() const
Returns the ScalarEvolution analysis used.
bool IsMaxOp
If the op a min/max kind, true if it&#39;s a max operation.
RecurrenceKind getRecurrenceKind()
Definition: LoopUtils.h:198
Value * getIncomingValue(unsigned i) const
Return incoming value number x.
Optional< const MDOperand * > findStringMetadataForLoop(Loop *TheLoop, StringRef Name)
Find string metadata for loop.
Definition: LoopUtils.cpp:1289
static unsigned getRecurrenceBinOp(RecurrenceKind Kind)
Returns the opcode of binary operation corresponding to the RecurrenceKind.
Definition: LoopUtils.cpp:686
const SCEV * getMulExpr(SmallVectorImpl< const SCEV *> &Ops, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)
Get a canonical multiply expression, or something simpler if possible.
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
void propagateIRFlags(Value *I, ArrayRef< Value *> VL, Value *OpValue=nullptr)
Get the intersection (logical and) of all of the potential IR flags of each scalar operation (VL) tha...
Definition: LoopUtils.cpp:1724
static bool isFirstOrderRecurrence(PHINode *Phi, Loop *TheLoop, DenseMap< Instruction *, Instruction *> &SinkAfter, DominatorTree *DT)
Returns true if Phi is a first-order recurrence.
Definition: LoopUtils.cpp:606
signed greater than
Definition: InstrTypes.h:912
char & LoopSimplifyID
The RecurrenceDescriptor is used to identify recurrences variables in a loop.
Definition: LoopUtils.h:64
Value * CreateGEP(Value *Ptr, ArrayRef< Value *> IdxList, const Twine &Name="")
Definition: IRBuilder.h:1374
0 0 1 0 True if ordered and greater than
Definition: InstrTypes.h:889
Value * transform(IRBuilder<> &B, Value *Index, ScalarEvolution *SE, const DataLayout &DL) const
Compute the transformed value of Index at offset StartValue using step StepValue. ...
Definition: LoopUtils.cpp:805
static IntegerType * get(LLVMContext &C, unsigned NumBits)
This static method is the primary way of constructing an IntegerType.
Definition: Type.cpp:240
bool contains(const LoopT *L) const
Return true if the specified loop is contained within in this loop.
Definition: LoopInfo.h:110
MinMaxRecurrenceKind getMinMaxKind()
Definition: LoopUtils.h:118
CallInst * CreateAddReduce(Value *Src)
Create a vector int add reduction intrinsic of the source vector.
Definition: IRBuilder.cpp:341
SmallPtrSet - This class implements a set which is optimized for holding SmallSize or less elements...
Definition: SmallPtrSet.h:418
Legacy wrapper pass to provide the SCEVAAResult object.
This is the shared class of boolean and integer constants.
Definition: Constants.h:84
Type * getType() const
Return the LLVM type of this SCEV expression.
A struct for saving information about induction variables.
Definition: LoopUtils.h:254
unsigned ComputeNumSignBits(const Value *Op, const DataLayout &DL, unsigned Depth=0, AssumptionCache *AC=nullptr, const Instruction *CxtI=nullptr, const DominatorTree *DT=nullptr)
Return the number of times the sign bit of the register is replicated into the other bits...
This pass provides access to the codegen interfaces that are needed for IR-level transformations.
CallInst * CreateIntMaxReduce(Value *Src, bool IsSigned=false)
Create a vector integer max reduction intrinsic of the source vector.
Definition: IRBuilder.cpp:366
AnalysisUsage & addRequiredID(const void *ID)
Definition: Pass.cpp:299
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:861
bool dominates(const Instruction *Def, const Use &U) const
Return true if Def dominates a use in User.
Definition: Dominators.cpp:244
Module.h This file contains the declarations for the Module class.
Instruction * user_back()
Specialize the methods defined in Value, as we know that an instruction can only be used by other ins...
Definition: Instruction.h:64
static bool isFloatingPointRecurrenceKind(RecurrenceKind Kind)
Returns true if the recurrence kind is a floating point kind.
Definition: LoopUtils.cpp:67
An interface layer with SCEV used to manage how we see SCEV expressions for values in the context of ...
signed less than
Definition: InstrTypes.h:914
LLVM_NODISCARD T pop_back_val()
Definition: SmallVector.h:382
ConstantInt * getInt32(uint32_t C)
Get a constant 32-bit value.
Definition: IRBuilder.h:307
static IntegerType * getIntNTy(LLVMContext &C, unsigned N)
Definition: Type.cpp:180
Value * CreateShuffleVector(Value *V1, Value *V2, Value *Mask, const Twine &Name="")
Definition: IRBuilder.h:1948
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
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:611
pred_range predecessors(BasicBlock *BB)
Definition: CFG.h:113
static Constant * get(Type *Ty, double V)
This returns a ConstantFP, or a vector containing a splat of a ConstantFP, for the specified value in...
Definition: Constants.cpp:674
CallInst * CreateFMulReduce(Value *Acc, Value *Src)
Create a vector fmul reduction intrinsic of the source vector.
Definition: IRBuilder.cpp:331
unsigned getNumIncomingValues() const
Return the number of incoming edges.
APInt getDemandedBits(Instruction *I)
Return the bits demanded from instruction I.
bool isCommutative() const
Return true if the instruction is commutative:
Definition: Instruction.h:452
Value * createTargetReduction(IRBuilder<> &B, const TargetTransformInfo *TTI, RecurrenceDescriptor &Desc, Value *Src, bool NoNaN=false)
Create a generic target reduction using a recurrence descriptor Desc The target is queried to determi...
Definition: LoopUtils.cpp:1685
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:133
unsigned getVectorNumElements() const
Definition: DerivedTypes.h:462
static Constant * getRecurrenceIdentity(RecurrenceKind K, Type *Tp)
Returns identity corresponding to the RecurrenceKind.
Definition: LoopUtils.cpp:660
const Module * getModule() const
Return the module owning the function this instruction belongs to or nullptr it the function does not...
Definition: Instruction.cpp:56
Class for arbitrary precision integers.
Definition: APInt.h:69
iterator_range< user_iterator > users()
Definition: Value.h:399
static Value * createMinMaxOp(IRBuilder<> &Builder, MinMaxRecurrenceKind RK, Value *Left, Value *Right)
Returns a Min/Max operation corresponding to MinMaxRecurrenceKind.
Definition: LoopUtils.cpp:711
This class uses information about analyze scalars to rewrite expressions in canonical form...
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool equals(StringRef RHS) const
equals - Check for string equality, this is more efficient than compare() when the relative ordering ...
Definition: StringRef.h:169
void append(in_iter in_start, in_iter in_end)
Add the specified range to the end of the SmallVector.
Definition: SmallVector.h:395
uint64_t getTypeSizeInBits(Type *Ty) const
Size examples:
Definition: DataLayout.h:560
uint64_t getTypeAllocSize(Type *Ty) const
Returns the offset in bytes between successive objects of the specified type, including alignment pad...
Definition: DataLayout.h:428
use_iterator use_begin()
Definition: Value.h:338
CallInst * CreateAndReduce(Value *Src)
Create a vector int AND reduction intrinsic of the source vector.
Definition: IRBuilder.cpp:351
static bool isZero(Value *V, const DataLayout &DL, DominatorTree *DT, AssumptionCache *AC)
Definition: Lint.cpp:546
MDNode * getLoopID() const
Return the llvm.loop loop id metadata node for this loop if it is present.
Definition: LoopInfo.cpp:214
static MachineInstr * getDef(unsigned Reg, const MachineRegisterInfo *MRI)
CallInst * CreateOrReduce(Value *Src)
Create a vector int OR reduction intrinsic of the source vector.
Definition: IRBuilder.cpp:356
LLVM_ATTRIBUTE_ALWAYS_INLINE iterator end()
Definition: SmallVector.h:121
CallInst * CreateIntMinReduce(Value *Src, bool IsSigned=false)
Create a vector integer min reduction intrinsic of the source vector.
Definition: IRBuilder.cpp:372
This class represents an analyzed expression in the program.
static bool isIntegerRecurrenceKind(RecurrenceKind Kind)
Returns true if the recurrence kind is an integer kind.
Definition: LoopUtils.cpp:52
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:62
StringRef getValueAsString() const
Return the attribute&#39;s value as a string.
Definition: Attributes.cpp:195
Represents a single loop in the control flow graph.
Definition: LoopInfo.h:445
ArrayRef< BlockT * > getBlocks() const
Get a list of the basic blocks which make up this loop.
Definition: LoopInfo.h:149
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:108
#define I(x, y, z)
Definition: MD5.cpp:58
#define N
MaxMin_match< ICmpInst, LHS, RHS, smax_pred_ty > m_SMax(const LHS &L, const RHS &R)
void getLoopAnalysisUsage(AnalysisUsage &AU)
Helper to consistently add the set of standard passes to a loop pass&#39;s AnalysisUsage.
Definition: LoopUtils.cpp:1226
CallInst * CreateMulReduce(Value *Src)
Create a vector int mul reduction intrinsic of the source vector.
Definition: IRBuilder.cpp:346
LLVM_NODISCARD std::enable_if<!is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type >::type dyn_cast(const Y &Val)
Definition: Casting.h:323
block_iterator block_end() const
Definition: LoopInfo.h:155
size_type count(const_arg_type_t< KeyT > Val) const
Return 1 if the specified key is in the map, 0 otherwise.
Definition: DenseMap.h:141
SmallVector< DomTreeNode *, 16 > collectChildrenInLoop(DomTreeNode *N, const Loop *CurLoop)
Does a BFS from a given node to all of its children inside a given loop.
Definition: LoopUtils.cpp:1325
const unsigned Kind
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
user_iterator user_begin()
Definition: Value.h:375
static std::pair< Type *, bool > computeRecurrenceType(Instruction *Exit, DemandedBits *DB, AssumptionCache *AC, DominatorTree *DT)
Compute the minimal bit width needed to represent a reduction whose exit instruction is given by Exit...
Definition: LoopUtils.cpp:113
MaxMin_match< FCmpInst, LHS, RHS, ofmax_pred_ty > m_OrdFMax(const LHS &L, const RHS &R)
Match an &#39;ordered&#39; floating point maximum function.
LLVM Value Representation.
Definition: Value.h:73
succ_range successors(BasicBlock *BB)
Definition: CFG.h:149
const SCEV * getSCEV(Value *V)
Return a SCEV expression for the full generality of the specified expression.
bool useReductionIntrinsic(unsigned Opcode, Type *Ty, ReductionFlags Flags) const
constexpr char Size[]
Key for Kernel::Arg::Metadata::mSize.
std::underlying_type< E >::type Mask()
Get a bitmask with 1s in all places up to the high-order bit of E&#39;s largest value.
Definition: BitmaskEnum.h:81
void setFastMathFlags(FastMathFlags NewFMF)
Set the fast-math flags to be used with generated fp-math operators.
Definition: IRBuilder.h:220
BasicBlock::iterator GetInsertPoint() const
Definition: IRBuilder.h:122
Attribute getFnAttribute(Attribute::AttrKind Kind) const
Return the attribute for the given attribute kind.
Definition: Function.h:317
bool formDedicatedExitBlocks(Loop *L, DominatorTree *DT, LoopInfo *LI, bool PreserveLCSSA)
Ensure that all exit blocks of the loop are dedicated exits.
Definition: LoopUtils.cpp:1143
const SCEV * getUnknown(Value *V)
The legacy pass manager&#39;s analysis pass to compute loop information.
Definition: LoopInfo.h:964
bool hasOneUse() const
Return true if there is exactly one user of this value.
Definition: Value.h:412
Convenience struct for specifying and reasoning about fast-math flags.
Definition: Operator.h:160
unsigned greater than
Definition: InstrTypes.h:908
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
This is the interface for LLVM&#39;s primary stateless and local alias analysis.
PassRegistry - This class manages the registration and intitialization of the pass subsystem as appli...
Definition: PassRegistry.h:39
A single uniqued string.
Definition: Metadata.h:602
bool isNonNegative() const
Returns true if this value is known to be non-negative.
Definition: KnownBits.h:99
Legacy analysis pass which computes a DominatorTree.
Definition: Dominators.h:254
This pass exposes codegen information to IR-level passes.
A wrapper pass to provide the legacy pass manager access to a suitably prepared AAResults object...
int64_t getSExtValue() const
Return the constant as a 64-bit integer value after it has been sign extended as appropriate for the ...
Definition: Constants.h:157
const TerminatorInst * 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:138
CallInst * CreateFPMaxReduce(Value *Src, bool NoNaN=false)
Create a vector float max reduction intrinsic of the source vector.
Definition: IRBuilder.cpp:378
unsigned getNumOperands() const
Return number of MDNode operands.
Definition: Metadata.h:1073
#define LLVM_DEBUG(X)
Definition: Debug.h:119
bool extractProfMetadata(uint64_t &TrueVal, uint64_t &FalseVal) const
Retrieve the raw weight values of a conditional branch or select.
Definition: Metadata.cpp:1315
iterator_range< block_iterator > blocks() const
Definition: LoopInfo.h:156
bool isDoubleTy() const
Return true if this is &#39;double&#39;, a 64-bit IEEE fp type.
Definition: Type.h:150
static Value * addFastMathFlag(Value *V)
Adds a &#39;fast&#39; flag to floating point operations.
Definition: LoopUtils.cpp:1523
block_iterator block_begin() const
Definition: LoopInfo.h:154
BlockT * getExitingBlock() const
If getExitingBlocks would return exactly one block, return that block.
Definition: LoopInfoImpl.h:50
void computeKnownBits(const Value *V, KnownBits &Known, const DataLayout &DL, unsigned Depth=0, AssumptionCache *AC=nullptr, const Instruction *CxtI=nullptr, const DominatorTree *DT=nullptr, OptimizationRemarkEmitter *ORE=nullptr)
Determine which bits of V are known to be either zero or one and return them in the KnownZero/KnownOn...
bool NoNaN
If op is an fp min/max, whether NaNs may be present.
bool use_empty() const
Definition: Value.h:322
static Constant * get(ArrayRef< Constant *> V)
Definition: Constants.cpp:1046
bind_ty< Instruction > m_Instruction(Instruction *&I)
Match an instruction, capturing it if we match.
Definition: PatternMatch.h:467
bool empty() const
empty - Check if the array is empty.
Definition: ArrayRef.h:144
RecurrenceKind
This enum represents the kinds of recurrences that we support.
Definition: LoopUtils.h:67
const BasicBlock * getParent() const
Definition: Instruction.h:67
This class represents a constant integer value.
Legacy wrapper pass to provide the BasicAAResult object.
bool IsSigned
Whether the operation is a signed int reduction.
bool is_contained(R &&Range, const E &Element)
Wrapper function around std::find to detect if an element exists in a container.
Definition: STLExtras.h:967