LLVM  7.0.0svn
HexagonVectorLoopCarriedReuse.cpp
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1 //===- HexagonVectorLoopCarriedReuse.cpp ----------------------------------===//
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 pass removes the computation of provably redundant expressions that have
11 // been computed earlier in a previous iteration. It relies on the use of PHIs
12 // to identify loop carried dependences. This is scalar replacement for vector
13 // types.
14 //
15 //-----------------------------------------------------------------------------
16 // Motivation: Consider the case where we have the following loop structure.
17 //
18 // Loop:
19 // t0 = a[i];
20 // t1 = f(t0);
21 // t2 = g(t1);
22 // ...
23 // t3 = a[i+1];
24 // t4 = f(t3);
25 // t5 = g(t4);
26 // t6 = op(t2, t5)
27 // cond_branch <Loop>
28 //
29 // This can be converted to
30 // t00 = a[0];
31 // t10 = f(t00);
32 // t20 = g(t10);
33 // Loop:
34 // t2 = t20;
35 // t3 = a[i+1];
36 // t4 = f(t3);
37 // t5 = g(t4);
38 // t6 = op(t2, t5)
39 // t20 = t5
40 // cond_branch <Loop>
41 //
42 // SROA does a good job of reusing a[i+1] as a[i] in the next iteration.
43 // Such a loop comes to this pass in the following form.
44 //
45 // LoopPreheader:
46 // X0 = a[0];
47 // Loop:
48 // X2 = PHI<(X0, LoopPreheader), (X1, Loop)>
49 // t1 = f(X2) <-- I1
50 // t2 = g(t1)
51 // ...
52 // X1 = a[i+1]
53 // t4 = f(X1) <-- I2
54 // t5 = g(t4)
55 // t6 = op(t2, t5)
56 // cond_branch <Loop>
57 //
58 // In this pass, we look for PHIs such as X2 whose incoming values come only
59 // from the Loop Preheader and over the backedge and additionaly, both these
60 // values are the results of the same operation in terms of opcode. We call such
61 // a PHI node a dependence chain or DepChain. In this case, the dependence of X2
62 // over X1 is carried over only one iteration and so the DepChain is only one
63 // PHI node long.
64 //
65 // Then, we traverse the uses of the PHI (X2) and the uses of the value of the
66 // PHI coming over the backedge (X1). We stop at the first pair of such users
67 // I1 (of X2) and I2 (of X1) that meet the following conditions.
68 // 1. I1 and I2 are the same operation, but with different operands.
69 // 2. X2 and X1 are used at the same operand number in the two instructions.
70 // 3. All other operands Op1 of I1 and Op2 of I2 are also such that there is a
71 // a DepChain from Op1 to Op2 of the same length as that between X2 and X1.
72 //
73 // We then make the following transformation
74 // LoopPreheader:
75 // X0 = a[0];
76 // Y0 = f(X0);
77 // Loop:
78 // X2 = PHI<(X0, LoopPreheader), (X1, Loop)>
79 // Y2 = PHI<(Y0, LoopPreheader), (t4, Loop)>
80 // t1 = f(X2) <-- Will be removed by DCE.
81 // t2 = g(Y2)
82 // ...
83 // X1 = a[i+1]
84 // t4 = f(X1)
85 // t5 = g(t4)
86 // t6 = op(t2, t5)
87 // cond_branch <Loop>
88 //
89 // We proceed until we cannot find any more such instructions I1 and I2.
90 //
91 // --- DepChains & Loop carried dependences ---
92 // Consider a single basic block loop such as
93 //
94 // LoopPreheader:
95 // X0 = ...
96 // Y0 = ...
97 // Loop:
98 // X2 = PHI<(X0, LoopPreheader), (X1, Loop)>
99 // Y2 = PHI<(Y0, LoopPreheader), (X2, Loop)>
100 // ...
101 // X1 = ...
102 // ...
103 // cond_branch <Loop>
104 //
105 // Then there is a dependence between X2 and X1 that goes back one iteration,
106 // i.e. X1 is used as X2 in the very next iteration. We represent this as a
107 // DepChain from X2 to X1 (X2->X1).
108 // Similarly, there is a dependence between Y2 and X1 that goes back two
109 // iterations. X1 is used as Y2 two iterations after it is computed. This is
110 // represented by a DepChain as (Y2->X2->X1).
111 //
112 // A DepChain has the following properties.
113 // 1. Num of edges in DepChain = Number of Instructions in DepChain = Number of
114 // iterations of carried dependence + 1.
115 // 2. All instructions in the DepChain except the last are PHIs.
116 //
117 //===----------------------------------------------------------------------===//
118 
119 #include "llvm/ADT/SetVector.h"
120 #include "llvm/ADT/SmallVector.h"
121 #include "llvm/ADT/Statistic.h"
122 #include "llvm/Analysis/LoopInfo.h"
123 #include "llvm/Analysis/LoopPass.h"
124 #include "llvm/IR/BasicBlock.h"
125 #include "llvm/IR/DerivedTypes.h"
126 #include "llvm/IR/IRBuilder.h"
127 #include "llvm/IR/Instruction.h"
128 #include "llvm/IR/Instructions.h"
129 #include "llvm/IR/IntrinsicInst.h"
130 #include "llvm/IR/Intrinsics.h"
131 #include "llvm/IR/Use.h"
132 #include "llvm/IR/User.h"
133 #include "llvm/IR/Value.h"
134 #include "llvm/Pass.h"
135 #include "llvm/Support/Casting.h"
137 #include "llvm/Support/Compiler.h"
138 #include "llvm/Support/Debug.h"
140 #include "llvm/Transforms/Scalar.h"
141 #include "llvm/Transforms/Utils.h"
142 #include <algorithm>
143 #include <cassert>
144 #include <cstddef>
145 #include <map>
146 #include <memory>
147 #include <set>
148 
149 using namespace llvm;
150 
151 #define DEBUG_TYPE "hexagon-vlcr"
152 
153 STATISTIC(HexagonNumVectorLoopCarriedReuse,
154  "Number of values that were reused from a previous iteration.");
155 
156 static cl::opt<int> HexagonVLCRIterationLim("hexagon-vlcr-iteration-lim",
157  cl::Hidden,
158  cl::desc("Maximum distance of loop carried dependences that are handled"),
160 
161 namespace llvm {
162 
165 
166 } // end namespace llvm
167 
168 namespace {
169 
170  // See info about DepChain in the comments at the top of this file.
171  using ChainOfDependences = SmallVector<Instruction *, 4>;
172 
173  class DepChain {
174  ChainOfDependences Chain;
175 
176  public:
177  bool isIdentical(DepChain &Other) const {
178  if (Other.size() != size())
179  return false;
180  ChainOfDependences &OtherChain = Other.getChain();
181  for (int i = 0; i < size(); ++i) {
182  if (Chain[i] != OtherChain[i])
183  return false;
184  }
185  return true;
186  }
187 
188  ChainOfDependences &getChain() {
189  return Chain;
190  }
191 
192  int size() const {
193  return Chain.size();
194  }
195 
196  void clear() {
197  Chain.clear();
198  }
199 
200  void push_back(Instruction *I) {
201  Chain.push_back(I);
202  }
203 
204  int iterations() const {
205  return size() - 1;
206  }
207 
208  Instruction *front() const {
209  return Chain.front();
210  }
211 
212  Instruction *back() const {
213  return Chain.back();
214  }
215 
216  Instruction *&operator[](const int index) {
217  return Chain[index];
218  }
219 
220  friend raw_ostream &operator<< (raw_ostream &OS, const DepChain &D);
221  };
222 
224  raw_ostream &operator<<(raw_ostream &OS, const DepChain &D) {
225  const ChainOfDependences &CD = D.Chain;
226  int ChainSize = CD.size();
227  OS << "**DepChain Start::**\n";
228  for (int i = 0; i < ChainSize -1; ++i) {
229  OS << *(CD[i]) << " -->\n";
230  }
231  OS << *CD[ChainSize-1] << "\n";
232  return OS;
233  }
234 
235  struct ReuseValue {
236  Instruction *Inst2Replace = nullptr;
237 
238  // In the new PHI node that we'll construct this is the value that'll be
239  // used over the backedge. This is teh value that gets reused from a
240  // previous iteration.
241  Instruction *BackedgeInst = nullptr;
242 
243  ReuseValue() = default;
244 
245  void reset() { Inst2Replace = nullptr; BackedgeInst = nullptr; }
246  bool isDefined() { return Inst2Replace != nullptr; }
247  };
248 
250  raw_ostream &operator<<(raw_ostream &OS, const ReuseValue &RU) {
251  OS << "** ReuseValue ***\n";
252  OS << "Instruction to Replace: " << *(RU.Inst2Replace) << "\n";
253  OS << "Backedge Instruction: " << *(RU.BackedgeInst) << "\n";
254  return OS;
255  }
256 
257  class HexagonVectorLoopCarriedReuse : public LoopPass {
258  public:
259  static char ID;
260 
261  explicit HexagonVectorLoopCarriedReuse() : LoopPass(ID) {
264  }
265 
266  StringRef getPassName() const override {
267  return "Hexagon-specific loop carried reuse for HVX vectors";
268  }
269 
270  void getAnalysisUsage(AnalysisUsage &AU) const override {
275  AU.setPreservesCFG();
276  }
277 
278  bool runOnLoop(Loop *L, LPPassManager &LPM) override;
279 
280  private:
281  SetVector<DepChain *> Dependences;
282  std::set<Instruction *> ReplacedInsts;
283  Loop *CurLoop;
284  ReuseValue ReuseCandidate;
285 
286  bool doVLCR();
287  void findLoopCarriedDeps();
288  void findValueToReuse();
289  void findDepChainFromPHI(Instruction *I, DepChain &D);
290  void reuseValue();
291  Value *findValueInBlock(Value *Op, BasicBlock *BB);
292  bool isDepChainBtwn(Instruction *I1, Instruction *I2, int Iters);
293  DepChain *getDepChainBtwn(Instruction *I1, Instruction *I2);
294  bool isEquivalentOperation(Instruction *I1, Instruction *I2);
295  bool canReplace(Instruction *I);
296  };
297 
298 } // end anonymous namespace
299 
301 
302 INITIALIZE_PASS_BEGIN(HexagonVectorLoopCarriedReuse, "hexagon-vlcr",
303  "Hexagon-specific predictive commoning for HVX vectors", false, false)
305 INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
306 INITIALIZE_PASS_DEPENDENCY(LCSSAWrapperPass)
307 INITIALIZE_PASS_END(HexagonVectorLoopCarriedReuse, "hexagon-vlcr",
308  "Hexagon-specific predictive commoning for HVX vectors", false, false)
309 
310 bool HexagonVectorLoopCarriedReuse::runOnLoop(Loop *L, LPPassManager &LPM) {
311  if (skipLoop(L))
312  return false;
313 
314  if (!L->getLoopPreheader())
315  return false;
316 
317  // Work only on innermost loops.
318  if (!L->getSubLoops().empty())
319  return false;
320 
321  // Work only on single basic blocks loops.
322  if (L->getNumBlocks() != 1)
323  return false;
324 
325  CurLoop = L;
326 
327  return doVLCR();
328 }
329 
330 bool HexagonVectorLoopCarriedReuse::isEquivalentOperation(Instruction *I1,
331  Instruction *I2) {
332  if (!I1->isSameOperationAs(I2))
333  return false;
334  // This check is in place specifically for intrinsics. isSameOperationAs will
335  // return two for any two hexagon intrinsics because they are essentially the
336  // same instruciton (CallInst). We need to scratch the surface to see if they
337  // are calls to the same function.
338  if (CallInst *C1 = dyn_cast<CallInst>(I1)) {
339  if (CallInst *C2 = dyn_cast<CallInst>(I2)) {
340  if (C1->getCalledFunction() != C2->getCalledFunction())
341  return false;
342  }
343  }
344 
345  // If both the Instructions are of Vector Type and any of the element
346  // is integer constant, check their values too for equivalence.
347  if (I1->getType()->isVectorTy() && I2->getType()->isVectorTy()) {
348  unsigned NumOperands = I1->getNumOperands();
349  for (unsigned i = 0; i < NumOperands; ++i) {
352  if(!C1) continue;
353  assert(C2);
354  if (C1->getSExtValue() != C2->getSExtValue())
355  return false;
356  }
357  }
358 
359  return true;
360 }
361 
362 bool HexagonVectorLoopCarriedReuse::canReplace(Instruction *I) {
363  const IntrinsicInst *II = dyn_cast<IntrinsicInst>(I);
364  if (II &&
365  (II->getIntrinsicID() == Intrinsic::hexagon_V6_hi ||
366  II->getIntrinsicID() == Intrinsic::hexagon_V6_lo)) {
367  DEBUG(dbgs() << "Not considering for reuse: " << *II << "\n");
368  return false;
369  }
370  return true;
371 }
372 void HexagonVectorLoopCarriedReuse::findValueToReuse() {
373  for (auto *D : Dependences) {
374  DEBUG(dbgs() << "Processing dependence " << *(D->front()) << "\n");
375  if (D->iterations() > HexagonVLCRIterationLim) {
376  DEBUG(dbgs() <<
377  ".. Skipping because number of iterations > than the limit\n");
378  continue;
379  }
380 
381  PHINode *PN = cast<PHINode>(D->front());
382  Instruction *BEInst = D->back();
383  int Iters = D->iterations();
384  BasicBlock *BB = PN->getParent();
385  DEBUG(dbgs() << "Checking if any uses of " << *PN << " can be reused\n");
386 
388  for (auto UI = PN->use_begin(), E = PN->use_end(); UI != E; ++UI) {
389  Use &U = *UI;
390  Instruction *User = cast<Instruction>(U.getUser());
391 
392  if (User->getParent() != BB)
393  continue;
394  if (ReplacedInsts.count(User)) {
395  DEBUG(dbgs() << *User << " has already been replaced. Skipping...\n");
396  continue;
397  }
398  if (isa<PHINode>(User))
399  continue;
400  if (User->mayHaveSideEffects())
401  continue;
402  if (!canReplace(User))
403  continue;
404 
405  PNUsers.push_back(User);
406  }
407  DEBUG(dbgs() << PNUsers.size() << " use(s) of the PHI in the block\n");
408 
409  // For each interesting use I of PN, find an Instruction BEUser that
410  // performs the same operation as I on BEInst and whose other operands,
411  // if any, can also be rematerialized in OtherBB. We stop when we find the
412  // first such Instruction BEUser. This is because once BEUser is
413  // rematerialized in OtherBB, we may find more such "fixup" opportunities
414  // in this block. So, we'll start over again.
415  for (Instruction *I : PNUsers) {
416  for (auto UI = BEInst->use_begin(), E = BEInst->use_end(); UI != E;
417  ++UI) {
418  Use &U = *UI;
419  Instruction *BEUser = cast<Instruction>(U.getUser());
420 
421  if (BEUser->getParent() != BB)
422  continue;
423  if (!isEquivalentOperation(I, BEUser))
424  continue;
425 
426  int NumOperands = I->getNumOperands();
427 
428  for (int OpNo = 0; OpNo < NumOperands; ++OpNo) {
429  Value *Op = I->getOperand(OpNo);
430  Instruction *OpInst = dyn_cast<Instruction>(Op);
431  if (!OpInst)
432  continue;
433 
434  Value *BEOp = BEUser->getOperand(OpNo);
435  Instruction *BEOpInst = dyn_cast<Instruction>(BEOp);
436 
437  if (!isDepChainBtwn(OpInst, BEOpInst, Iters)) {
438  BEUser = nullptr;
439  break;
440  }
441  }
442  if (BEUser) {
443  DEBUG(dbgs() << "Found Value for reuse.\n");
444  ReuseCandidate.Inst2Replace = I;
445  ReuseCandidate.BackedgeInst = BEUser;
446  return;
447  } else
448  ReuseCandidate.reset();
449  }
450  }
451  }
452  ReuseCandidate.reset();
453 }
454 
455 Value *HexagonVectorLoopCarriedReuse::findValueInBlock(Value *Op,
456  BasicBlock *BB) {
457  PHINode *PN = dyn_cast<PHINode>(Op);
458  assert(PN);
459  Value *ValueInBlock = PN->getIncomingValueForBlock(BB);
460  return ValueInBlock;
461 }
462 
463 void HexagonVectorLoopCarriedReuse::reuseValue() {
464  DEBUG(dbgs() << ReuseCandidate);
465  Instruction *Inst2Replace = ReuseCandidate.Inst2Replace;
466  Instruction *BEInst = ReuseCandidate.BackedgeInst;
467  int NumOperands = Inst2Replace->getNumOperands();
468  std::map<Instruction *, DepChain *> DepChains;
469  int Iterations = -1;
470  BasicBlock *LoopPH = CurLoop->getLoopPreheader();
471 
472  for (int i = 0; i < NumOperands; ++i) {
473  Instruction *I = dyn_cast<Instruction>(Inst2Replace->getOperand(i));
474  if(!I)
475  continue;
476  else {
477  Instruction *J = cast<Instruction>(BEInst->getOperand(i));
478  DepChain *D = getDepChainBtwn(I, J);
479 
480  assert(D &&
481  "No DepChain between corresponding operands in ReuseCandidate\n");
482  if (Iterations == -1)
483  Iterations = D->iterations();
484  assert(Iterations == D->iterations() && "Iterations mismatch");
485  DepChains[I] = D;
486  }
487  }
488 
489  DEBUG(dbgs() << "reuseValue is making the following changes\n");
490 
491  SmallVector<Instruction *, 4> InstsInPreheader;
492  for (int i = 0; i < Iterations; ++i) {
493  Instruction *InstInPreheader = Inst2Replace->clone();
495  for (int j = 0; j < NumOperands; ++j) {
496  Instruction *I = dyn_cast<Instruction>(Inst2Replace->getOperand(j));
497  if (!I)
498  continue;
499  // Get the DepChain corresponding to this operand.
500  DepChain &D = *DepChains[I];
501  // Get the PHI for the iteration number and find
502  // the incoming value from the Loop Preheader for
503  // that PHI.
504  Value *ValInPreheader = findValueInBlock(D[i], LoopPH);
505  InstInPreheader->setOperand(j, ValInPreheader);
506  }
507  InstsInPreheader.push_back(InstInPreheader);
508  InstInPreheader->setName(Inst2Replace->getName() + ".hexagon.vlcr");
509  InstInPreheader->insertBefore(LoopPH->getTerminator());
510  DEBUG(dbgs() << "Added " << *InstInPreheader << " to " << LoopPH->getName()
511  << "\n");
512  }
513  BasicBlock *BB = BEInst->getParent();
514  IRBuilder<> IRB(BB);
515  IRB.SetInsertPoint(BB->getFirstNonPHI());
516  Value *BEVal = BEInst;
517  PHINode *NewPhi;
518  for (int i = Iterations-1; i >=0 ; --i) {
519  Instruction *InstInPreheader = InstsInPreheader[i];
520  NewPhi = IRB.CreatePHI(InstInPreheader->getType(), 2);
521  NewPhi->addIncoming(InstInPreheader, LoopPH);
522  NewPhi->addIncoming(BEVal, BB);
523  DEBUG(dbgs() << "Adding " << *NewPhi << " to " << BB->getName() << "\n");
524  BEVal = NewPhi;
525  }
526  // We are in LCSSA form. So, a value defined inside the Loop is used only
527  // inside the loop. So, the following is safe.
528  Inst2Replace->replaceAllUsesWith(NewPhi);
529  ReplacedInsts.insert(Inst2Replace);
530  ++HexagonNumVectorLoopCarriedReuse;
531 }
532 
533 bool HexagonVectorLoopCarriedReuse::doVLCR() {
534  assert(CurLoop->getSubLoops().empty() &&
535  "Can do VLCR on the innermost loop only");
536  assert((CurLoop->getNumBlocks() == 1) &&
537  "Can do VLCR only on single block loops");
538 
539  bool Changed = false;
540  bool Continue;
541 
542  DEBUG(dbgs() << "Working on Loop: " << *CurLoop->getHeader() << "\n");
543  do {
544  // Reset datastructures.
545  Dependences.clear();
546  Continue = false;
547 
548  findLoopCarriedDeps();
549  findValueToReuse();
550  if (ReuseCandidate.isDefined()) {
551  reuseValue();
552  Changed = true;
553  Continue = true;
554  }
555  llvm::for_each(Dependences, std::default_delete<DepChain>());
556  } while (Continue);
557  return Changed;
558 }
559 
560 void HexagonVectorLoopCarriedReuse::findDepChainFromPHI(Instruction *I,
561  DepChain &D) {
562  PHINode *PN = dyn_cast<PHINode>(I);
563  if (!PN) {
564  D.push_back(I);
565  return;
566  } else {
567  auto NumIncomingValues = PN->getNumIncomingValues();
568  if (NumIncomingValues != 2) {
569  D.clear();
570  return;
571  }
572 
573  BasicBlock *BB = PN->getParent();
574  if (BB != CurLoop->getHeader()) {
575  D.clear();
576  return;
577  }
578 
579  Value *BEVal = PN->getIncomingValueForBlock(BB);
580  Instruction *BEInst = dyn_cast<Instruction>(BEVal);
581  // This is a single block loop with a preheader, so at least
582  // one value should come over the backedge.
583  assert(BEInst && "There should be a value over the backedge");
584 
585  Value *PreHdrVal =
586  PN->getIncomingValueForBlock(CurLoop->getLoopPreheader());
587  if(!PreHdrVal || !isa<Instruction>(PreHdrVal)) {
588  D.clear();
589  return;
590  }
591  D.push_back(PN);
592  findDepChainFromPHI(BEInst, D);
593  }
594 }
595 
596 bool HexagonVectorLoopCarriedReuse::isDepChainBtwn(Instruction *I1,
597  Instruction *I2,
598  int Iters) {
599  for (auto *D : Dependences) {
600  if (D->front() == I1 && D->back() == I2 && D->iterations() == Iters)
601  return true;
602  }
603  return false;
604 }
605 
606 DepChain *HexagonVectorLoopCarriedReuse::getDepChainBtwn(Instruction *I1,
607  Instruction *I2) {
608  for (auto *D : Dependences) {
609  if (D->front() == I1 && D->back() == I2)
610  return D;
611  }
612  return nullptr;
613 }
614 
615 void HexagonVectorLoopCarriedReuse::findLoopCarriedDeps() {
616  BasicBlock *BB = CurLoop->getHeader();
617  for (auto I = BB->begin(), E = BB->end(); I != E && isa<PHINode>(I); ++I) {
618  auto *PN = cast<PHINode>(I);
619  if (!isa<VectorType>(PN->getType()))
620  continue;
621 
622  DepChain *D = new DepChain();
623  findDepChainFromPHI(PN, *D);
624  if (D->size() != 0)
625  Dependences.insert(D);
626  else
627  delete D;
628  }
629  DEBUG(dbgs() << "Found " << Dependences.size() << " dependences\n");
630  DEBUG(for (size_t i = 0; i < Dependences.size(); ++i) {
631  dbgs() << *Dependences[i] << "\n";
632  });
633 }
634 
636  return new HexagonVectorLoopCarriedReuse();
637 }
Pass interface - Implemented by all &#39;passes&#39;.
Definition: Pass.h:81
use_iterator use_end()
Definition: Value.h:352
void addIncoming(Value *V, BasicBlock *BB)
Add an incoming value to the end of the PHI list.
static PassRegistry * getPassRegistry()
getPassRegistry - Access the global registry object, which is automatically initialized at applicatio...
bool isSameOperationAs(const Instruction *I, unsigned flags=0) const
This function determines if the specified instruction executes the same operation as the current one...
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
LLVM_ATTRIBUTE_ALWAYS_INLINE size_type size() const
Definition: SmallVector.h:136
This class represents a function call, abstracting a target machine&#39;s calling convention.
#define LLVM_ATTRIBUTE_UNUSED
Definition: Compiler.h:144
static cl::opt< int > HexagonVLCRIterationLim("hexagon-vlcr-iteration-lim", cl::Hidden, cl::desc("Maximum distance of loop carried dependences that are handled"), cl::init(2), cl::ZeroOrMore)
STATISTIC(NumFunctions, "Total number of functions")
bool isVectorTy() const
True if this is an instance of VectorType.
Definition: Type.h:227
This defines the Use class.
iterator begin()
Instruction iterator methods.
Definition: BasicBlock.h:264
AnalysisUsage & addRequired()
#define INITIALIZE_PASS_DEPENDENCY(depName)
Definition: PassSupport.h:51
hexagon Hexagon specific predictive commoning for HVX vectors
A Use represents the edge between a Value definition and its users.
Definition: Use.h:56
INITIALIZE_PASS_BEGIN(HexagonVectorLoopCarriedReuse, "hexagon-vlcr", "Hexagon-specific predictive commoning for HVX vectors", false, false) INITIALIZE_PASS_END(HexagonVectorLoopCarriedReuse
This provides a uniform API for creating instructions and inserting them into a basic block: either a...
Definition: IRBuilder.h:677
void setName(const Twine &Name)
Change the name of the value.
Definition: Value.cpp:295
Instruction * clone() const
Create a copy of &#39;this&#39; instruction that is identical in all ways except the following: ...
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
AnalysisUsage & addPreservedID(const void *ID)
void replaceAllUsesWith(Value *V)
Change all uses of this to point to a new Value.
Definition: Value.cpp:439
void SetInsertPoint(BasicBlock *TheBB)
This specifies that created instructions should be appended to the end of the specified block...
Definition: IRBuilder.h:127
Value * getOperand(unsigned i) const
Definition: User.h:170
void initializeHexagonVectorLoopCarriedReusePass(PassRegistry &)
initializer< Ty > init(const Ty &Val)
Definition: CommandLine.h:406
void insertBefore(Instruction *InsertPos)
Insert an unlinked instruction into a basic block immediately before the specified instruction...
Definition: Instruction.cpp:73
LLVM Basic Block Representation.
Definition: BasicBlock.h:59
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
Value * getIncomingValueForBlock(const BasicBlock *BB) const
char & LCSSAID
Definition: LCSSA.cpp:418
bool mayHaveSideEffects() const
Return true if the instruction may have side effects.
Definition: Instruction.h:536
Represent the analysis usage information of a pass.
INITIALIZE_PASS_END(RegBankSelect, DEBUG_TYPE, "Assign register bank of generic virtual registers", false, false) RegBankSelect
char & LoopSimplifyID
Intrinsic::ID getIntrinsicID() const
Return the intrinsic ID of this intrinsic.
Definition: IntrinsicInst.h:51
PHINode * CreatePHI(Type *Ty, unsigned NumReservedValues, const Twine &Name="")
Definition: IRBuilder.h:1807
unsigned getNumOperands() const
Definition: User.h:192
This is the shared class of boolean and integer constants.
Definition: Constants.h:84
iterator end()
Definition: BasicBlock.h:266
AnalysisUsage & addRequiredID(const void *ID)
Definition: Pass.cpp:298
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:862
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
void setPreservesCFG()
This function should be called by the pass, iff they do not:
Definition: Pass.cpp:285
unsigned getNumIncomingValues() const
Return the number of incoming edges.
void setOperand(unsigned i, Value *Val)
Definition: User.h:175
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:132
static void clear(coro::Shape &Shape)
Definition: Coroutines.cpp:211
use_iterator use_begin()
Definition: Value.h:344
Pass * createHexagonVectorLoopCarriedReusePass()
Represents a single loop in the control flow graph.
Definition: LoopInfo.h:439
StringRef getName() const
Return a constant reference to the value&#39;s name.
Definition: Value.cpp:224
#define I(x, y, z)
Definition: MD5.cpp:58
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
raw_ostream & operator<<(raw_ostream &OS, const APInt &I)
Definition: APInt.h:2018
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
LLVM Value Representation.
Definition: Value.h:73
A vector that has set insertion semantics.
Definition: SetVector.h:41
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:44
#define DEBUG(X)
Definition: Debug.h:118
The legacy pass manager&#39;s analysis pass to compute loop information.
Definition: LoopInfo.h:958
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
PassRegistry - This class manages the registration and intitialization of the pass subsystem as appli...
Definition: PassRegistry.h:39
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
UnaryPredicate for_each(R &&Range, UnaryPredicate P)
Provide wrappers to std::for_each which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:839
for(unsigned i=Desc.getNumOperands(), e=OldMI.getNumOperands();i !=e;++i)
A wrapper class for inspecting calls to intrinsic functions.
Definition: IntrinsicInst.h:44
const BasicBlock * getParent() const
Definition: Instruction.h:67