1 //===- BBVectorize.cpp - A Basic-Block Vectorizer -------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements a basic-block vectorization pass. The algorithm was
11 // inspired by that used by the Vienna MAP Vectorizor by Franchetti and Kral,
12 // et al. It works by looking for chains of pairable operations and then
15 //===----------------------------------------------------------------------===//
17 #define BBV_NAME "bb-vectorize"
18 #define DEBUG_TYPE BBV_NAME
19 #include "llvm/Constants.h"
20 #include "llvm/DerivedTypes.h"
21 #include "llvm/Function.h"
22 #include "llvm/Instructions.h"
23 #include "llvm/IntrinsicInst.h"
24 #include "llvm/Intrinsics.h"
25 #include "llvm/LLVMContext.h"
26 #include "llvm/Pass.h"
27 #include "llvm/Type.h"
28 #include "llvm/ADT/DenseMap.h"
29 #include "llvm/ADT/DenseSet.h"
30 #include "llvm/ADT/SmallVector.h"
31 #include "llvm/ADT/Statistic.h"
32 #include "llvm/ADT/STLExtras.h"
33 #include "llvm/ADT/StringExtras.h"
34 #include "llvm/Analysis/AliasAnalysis.h"
35 #include "llvm/Analysis/AliasSetTracker.h"
36 #include "llvm/Analysis/ScalarEvolution.h"
37 #include "llvm/Analysis/ScalarEvolutionExpressions.h"
38 #include "llvm/Analysis/ValueTracking.h"
39 #include "llvm/Support/CommandLine.h"
40 #include "llvm/Support/Debug.h"
41 #include "llvm/Support/raw_ostream.h"
42 #include "llvm/Support/ValueHandle.h"
43 #include "llvm/Target/TargetData.h"
44 #include "llvm/Transforms/Vectorize.h"
49 static cl::opt<unsigned>
50 ReqChainDepth("bb-vectorize-req-chain-depth", cl::init(6), cl::Hidden,
51 cl::desc("The required chain depth for vectorization"));
53 static cl::opt<unsigned>
54 SearchLimit("bb-vectorize-search-limit", cl::init(400), cl::Hidden,
55 cl::desc("The maximum search distance for instruction pairs"));
58 SplatBreaksChain("bb-vectorize-splat-breaks-chain", cl::init(false), cl::Hidden,
59 cl::desc("Replicating one element to a pair breaks the chain"));
61 static cl::opt<unsigned>
62 VectorBits("bb-vectorize-vector-bits", cl::init(128), cl::Hidden,
63 cl::desc("The size of the native vector registers"));
65 static cl::opt<unsigned>
66 MaxIter("bb-vectorize-max-iter", cl::init(0), cl::Hidden,
67 cl::desc("The maximum number of pairing iterations"));
69 static cl::opt<unsigned>
70 MaxInsts("bb-vectorize-max-instr-per-group", cl::init(500), cl::Hidden,
71 cl::desc("The maximum number of pairable instructions per group"));
73 static cl::opt<unsigned>
74 MaxCandPairsForCycleCheck("bb-vectorize-max-cycle-check-pairs", cl::init(200),
75 cl::Hidden, cl::desc("The maximum number of candidate pairs with which to use"
76 " a full cycle check"));
79 NoInts("bb-vectorize-no-ints", cl::init(false), cl::Hidden,
80 cl::desc("Don't try to vectorize integer values"));
83 NoFloats("bb-vectorize-no-floats", cl::init(false), cl::Hidden,
84 cl::desc("Don't try to vectorize floating-point values"));
87 NoCasts("bb-vectorize-no-casts", cl::init(false), cl::Hidden,
88 cl::desc("Don't try to vectorize casting (conversion) operations"));
91 NoMath("bb-vectorize-no-math", cl::init(false), cl::Hidden,
92 cl::desc("Don't try to vectorize floating-point math intrinsics"));
95 NoFMA("bb-vectorize-no-fma", cl::init(false), cl::Hidden,
96 cl::desc("Don't try to vectorize the fused-multiply-add intrinsic"));
99 NoMemOps("bb-vectorize-no-mem-ops", cl::init(false), cl::Hidden,
100 cl::desc("Don't try to vectorize loads and stores"));
103 AlignedOnly("bb-vectorize-aligned-only", cl::init(false), cl::Hidden,
104 cl::desc("Only generate aligned loads and stores"));
107 NoMemOpBoost("bb-vectorize-no-mem-op-boost",
108 cl::init(false), cl::Hidden,
109 cl::desc("Don't boost the chain-depth contribution of loads and stores"));
112 FastDep("bb-vectorize-fast-dep", cl::init(false), cl::Hidden,
113 cl::desc("Use a fast instruction dependency analysis"));
117 DebugInstructionExamination("bb-vectorize-debug-instruction-examination",
118 cl::init(false), cl::Hidden,
119 cl::desc("When debugging is enabled, output information on the"
120 " instruction-examination process"));
122 DebugCandidateSelection("bb-vectorize-debug-candidate-selection",
123 cl::init(false), cl::Hidden,
124 cl::desc("When debugging is enabled, output information on the"
125 " candidate-selection process"));
127 DebugPairSelection("bb-vectorize-debug-pair-selection",
128 cl::init(false), cl::Hidden,
129 cl::desc("When debugging is enabled, output information on the"
130 " pair-selection process"));
132 DebugCycleCheck("bb-vectorize-debug-cycle-check",
133 cl::init(false), cl::Hidden,
134 cl::desc("When debugging is enabled, output information on the"
135 " cycle-checking process"));
138 STATISTIC(NumFusedOps, "Number of operations fused by bb-vectorize");
141 struct BBVectorize : public BasicBlockPass {
142 static char ID; // Pass identification, replacement for typeid
144 const VectorizeConfig Config;
146 BBVectorize(const VectorizeConfig &C = VectorizeConfig())
147 : BasicBlockPass(ID), Config(C) {
148 initializeBBVectorizePass(*PassRegistry::getPassRegistry());
151 BBVectorize(Pass *P, const VectorizeConfig &C)
152 : BasicBlockPass(ID), Config(C) {
153 AA = &P->getAnalysis<AliasAnalysis>();
154 SE = &P->getAnalysis<ScalarEvolution>();
155 TD = P->getAnalysisIfAvailable<TargetData>();
158 typedef std::pair<Value *, Value *> ValuePair;
159 typedef std::pair<ValuePair, size_t> ValuePairWithDepth;
160 typedef std::pair<ValuePair, ValuePair> VPPair; // A ValuePair pair
161 typedef std::pair<std::multimap<Value *, Value *>::iterator,
162 std::multimap<Value *, Value *>::iterator> VPIteratorPair;
163 typedef std::pair<std::multimap<ValuePair, ValuePair>::iterator,
164 std::multimap<ValuePair, ValuePair>::iterator>
171 // FIXME: const correct?
173 bool vectorizePairs(BasicBlock &BB);
175 bool getCandidatePairs(BasicBlock &BB,
176 BasicBlock::iterator &Start,
177 std::multimap<Value *, Value *> &CandidatePairs,
178 std::vector<Value *> &PairableInsts);
180 void computeConnectedPairs(std::multimap<Value *, Value *> &CandidatePairs,
181 std::vector<Value *> &PairableInsts,
182 std::multimap<ValuePair, ValuePair> &ConnectedPairs);
184 void buildDepMap(BasicBlock &BB,
185 std::multimap<Value *, Value *> &CandidatePairs,
186 std::vector<Value *> &PairableInsts,
187 DenseSet<ValuePair> &PairableInstUsers);
189 void choosePairs(std::multimap<Value *, Value *> &CandidatePairs,
190 std::vector<Value *> &PairableInsts,
191 std::multimap<ValuePair, ValuePair> &ConnectedPairs,
192 DenseSet<ValuePair> &PairableInstUsers,
193 DenseMap<Value *, Value *>& ChosenPairs);
195 void fuseChosenPairs(BasicBlock &BB,
196 std::vector<Value *> &PairableInsts,
197 DenseMap<Value *, Value *>& ChosenPairs);
199 bool isInstVectorizable(Instruction *I, bool &IsSimpleLoadStore);
201 bool areInstsCompatible(Instruction *I, Instruction *J,
202 bool IsSimpleLoadStore);
204 bool trackUsesOfI(DenseSet<Value *> &Users,
205 AliasSetTracker &WriteSet, Instruction *I,
206 Instruction *J, bool UpdateUsers = true,
207 std::multimap<Value *, Value *> *LoadMoveSet = 0);
209 void computePairsConnectedTo(
210 std::multimap<Value *, Value *> &CandidatePairs,
211 std::vector<Value *> &PairableInsts,
212 std::multimap<ValuePair, ValuePair> &ConnectedPairs,
215 bool pairsConflict(ValuePair P, ValuePair Q,
216 DenseSet<ValuePair> &PairableInstUsers,
217 std::multimap<ValuePair, ValuePair> *PairableInstUserMap = 0);
219 bool pairWillFormCycle(ValuePair P,
220 std::multimap<ValuePair, ValuePair> &PairableInstUsers,
221 DenseSet<ValuePair> &CurrentPairs);
224 std::multimap<Value *, Value *> &CandidatePairs,
225 std::vector<Value *> &PairableInsts,
226 std::multimap<ValuePair, ValuePair> &ConnectedPairs,
227 DenseSet<ValuePair> &PairableInstUsers,
228 std::multimap<ValuePair, ValuePair> &PairableInstUserMap,
229 DenseMap<Value *, Value *> &ChosenPairs,
230 DenseMap<ValuePair, size_t> &Tree,
231 DenseSet<ValuePair> &PrunedTree, ValuePair J,
234 void buildInitialTreeFor(
235 std::multimap<Value *, Value *> &CandidatePairs,
236 std::vector<Value *> &PairableInsts,
237 std::multimap<ValuePair, ValuePair> &ConnectedPairs,
238 DenseSet<ValuePair> &PairableInstUsers,
239 DenseMap<Value *, Value *> &ChosenPairs,
240 DenseMap<ValuePair, size_t> &Tree, ValuePair J);
242 void findBestTreeFor(
243 std::multimap<Value *, Value *> &CandidatePairs,
244 std::vector<Value *> &PairableInsts,
245 std::multimap<ValuePair, ValuePair> &ConnectedPairs,
246 DenseSet<ValuePair> &PairableInstUsers,
247 std::multimap<ValuePair, ValuePair> &PairableInstUserMap,
248 DenseMap<Value *, Value *> &ChosenPairs,
249 DenseSet<ValuePair> &BestTree, size_t &BestMaxDepth,
250 size_t &BestEffSize, VPIteratorPair ChoiceRange,
253 Value *getReplacementPointerInput(LLVMContext& Context, Instruction *I,
254 Instruction *J, unsigned o, bool &FlipMemInputs);
256 void fillNewShuffleMask(LLVMContext& Context, Instruction *J,
257 unsigned NumElem, unsigned MaskOffset, unsigned NumInElem,
258 unsigned IdxOffset, std::vector<Constant*> &Mask);
260 Value *getReplacementShuffleMask(LLVMContext& Context, Instruction *I,
263 Value *getReplacementInput(LLVMContext& Context, Instruction *I,
264 Instruction *J, unsigned o, bool FlipMemInputs);
266 void getReplacementInputsForPair(LLVMContext& Context, Instruction *I,
267 Instruction *J, SmallVector<Value *, 3> &ReplacedOperands,
268 bool &FlipMemInputs);
270 void replaceOutputsOfPair(LLVMContext& Context, Instruction *I,
271 Instruction *J, Instruction *K,
272 Instruction *&InsertionPt, Instruction *&K1,
273 Instruction *&K2, bool &FlipMemInputs);
275 void collectPairLoadMoveSet(BasicBlock &BB,
276 DenseMap<Value *, Value *> &ChosenPairs,
277 std::multimap<Value *, Value *> &LoadMoveSet,
280 void collectLoadMoveSet(BasicBlock &BB,
281 std::vector<Value *> &PairableInsts,
282 DenseMap<Value *, Value *> &ChosenPairs,
283 std::multimap<Value *, Value *> &LoadMoveSet);
285 bool canMoveUsesOfIAfterJ(BasicBlock &BB,
286 std::multimap<Value *, Value *> &LoadMoveSet,
287 Instruction *I, Instruction *J);
289 void moveUsesOfIAfterJ(BasicBlock &BB,
290 std::multimap<Value *, Value *> &LoadMoveSet,
291 Instruction *&InsertionPt,
292 Instruction *I, Instruction *J);
294 bool vectorizeBB(BasicBlock &BB) {
295 bool changed = false;
296 // Iterate a sufficient number of times to merge types of size 1 bit,
297 // then 2 bits, then 4, etc. up to half of the target vector width of the
298 // target vector register.
299 for (unsigned v = 2, n = 1;
300 v <= Config.VectorBits && (!Config.MaxIter || n <= Config.MaxIter);
302 DEBUG(dbgs() << "BBV: fusing loop #" << n <<
303 " for " << BB.getName() << " in " <<
304 BB.getParent()->getName() << "...\n");
305 if (vectorizePairs(BB))
311 DEBUG(dbgs() << "BBV: done!\n");
315 virtual bool runOnBasicBlock(BasicBlock &BB) {
316 AA = &getAnalysis<AliasAnalysis>();
317 SE = &getAnalysis<ScalarEvolution>();
318 TD = getAnalysisIfAvailable<TargetData>();
320 return vectorizeBB(BB);
323 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
324 BasicBlockPass::getAnalysisUsage(AU);
325 AU.addRequired<AliasAnalysis>();
326 AU.addRequired<ScalarEvolution>();
327 AU.addPreserved<AliasAnalysis>();
328 AU.addPreserved<ScalarEvolution>();
329 AU.setPreservesCFG();
332 // This returns the vector type that holds a pair of the provided type.
333 // If the provided type is already a vector, then its length is doubled.
334 static inline VectorType *getVecTypeForPair(Type *ElemTy) {
335 if (VectorType *VTy = dyn_cast<VectorType>(ElemTy)) {
336 unsigned numElem = VTy->getNumElements();
337 return VectorType::get(ElemTy->getScalarType(), numElem*2);
340 return VectorType::get(ElemTy, 2);
343 // Returns the weight associated with the provided value. A chain of
344 // candidate pairs has a length given by the sum of the weights of its
345 // members (one weight per pair; the weight of each member of the pair
346 // is assumed to be the same). This length is then compared to the
347 // chain-length threshold to determine if a given chain is significant
348 // enough to be vectorized. The length is also used in comparing
349 // candidate chains where longer chains are considered to be better.
350 // Note: when this function returns 0, the resulting instructions are
351 // not actually fused.
352 inline size_t getDepthFactor(Value *V) {
353 // InsertElement and ExtractElement have a depth factor of zero. This is
354 // for two reasons: First, they cannot be usefully fused. Second, because
355 // the pass generates a lot of these, they can confuse the simple metric
356 // used to compare the trees in the next iteration. Thus, giving them a
357 // weight of zero allows the pass to essentially ignore them in
358 // subsequent iterations when looking for vectorization opportunities
359 // while still tracking dependency chains that flow through those
361 if (isa<InsertElementInst>(V) || isa<ExtractElementInst>(V))
364 // Give a load or store half of the required depth so that load/store
365 // pairs will vectorize.
366 if (!Config.NoMemOpBoost && (isa<LoadInst>(V) || isa<StoreInst>(V)))
367 return Config.ReqChainDepth/2;
372 // This determines the relative offset of two loads or stores, returning
373 // true if the offset could be determined to be some constant value.
374 // For example, if OffsetInElmts == 1, then J accesses the memory directly
375 // after I; if OffsetInElmts == -1 then I accesses the memory
376 // directly after J. This function assumes that both instructions
377 // have the same type.
378 bool getPairPtrInfo(Instruction *I, Instruction *J,
379 Value *&IPtr, Value *&JPtr, unsigned &IAlignment, unsigned &JAlignment,
380 int64_t &OffsetInElmts) {
382 if (isa<LoadInst>(I)) {
383 IPtr = cast<LoadInst>(I)->getPointerOperand();
384 JPtr = cast<LoadInst>(J)->getPointerOperand();
385 IAlignment = cast<LoadInst>(I)->getAlignment();
386 JAlignment = cast<LoadInst>(J)->getAlignment();
388 IPtr = cast<StoreInst>(I)->getPointerOperand();
389 JPtr = cast<StoreInst>(J)->getPointerOperand();
390 IAlignment = cast<StoreInst>(I)->getAlignment();
391 JAlignment = cast<StoreInst>(J)->getAlignment();
394 const SCEV *IPtrSCEV = SE->getSCEV(IPtr);
395 const SCEV *JPtrSCEV = SE->getSCEV(JPtr);
397 // If this is a trivial offset, then we'll get something like
398 // 1*sizeof(type). With target data, which we need anyway, this will get
399 // constant folded into a number.
400 const SCEV *OffsetSCEV = SE->getMinusSCEV(JPtrSCEV, IPtrSCEV);
401 if (const SCEVConstant *ConstOffSCEV =
402 dyn_cast<SCEVConstant>(OffsetSCEV)) {
403 ConstantInt *IntOff = ConstOffSCEV->getValue();
404 int64_t Offset = IntOff->getSExtValue();
406 Type *VTy = cast<PointerType>(IPtr->getType())->getElementType();
407 int64_t VTyTSS = (int64_t) TD->getTypeStoreSize(VTy);
409 assert(VTy == cast<PointerType>(JPtr->getType())->getElementType());
411 OffsetInElmts = Offset/VTyTSS;
412 return (abs64(Offset) % VTyTSS) == 0;
418 // Returns true if the provided CallInst represents an intrinsic that can
420 bool isVectorizableIntrinsic(CallInst* I) {
421 Function *F = I->getCalledFunction();
422 if (!F) return false;
424 unsigned IID = F->getIntrinsicID();
425 if (!IID) return false;
430 case Intrinsic::sqrt:
431 case Intrinsic::powi:
435 case Intrinsic::log2:
436 case Intrinsic::log10:
438 case Intrinsic::exp2:
440 return Config.VectorizeMath;
442 return Config.VectorizeFMA;
446 // Returns true if J is the second element in some pair referenced by
447 // some multimap pair iterator pair.
448 template <typename V>
449 bool isSecondInIteratorPair(V J, std::pair<
450 typename std::multimap<V, V>::iterator,
451 typename std::multimap<V, V>::iterator> PairRange) {
452 for (typename std::multimap<V, V>::iterator K = PairRange.first;
453 K != PairRange.second; ++K)
454 if (K->second == J) return true;
460 // This function implements one vectorization iteration on the provided
461 // basic block. It returns true if the block is changed.
462 bool BBVectorize::vectorizePairs(BasicBlock &BB) {
464 BasicBlock::iterator Start = BB.getFirstInsertionPt();
466 std::vector<Value *> AllPairableInsts;
467 DenseMap<Value *, Value *> AllChosenPairs;
470 std::vector<Value *> PairableInsts;
471 std::multimap<Value *, Value *> CandidatePairs;
472 ShouldContinue = getCandidatePairs(BB, Start, CandidatePairs,
474 if (PairableInsts.empty()) continue;
476 // Now we have a map of all of the pairable instructions and we need to
477 // select the best possible pairing. A good pairing is one such that the
478 // users of the pair are also paired. This defines a (directed) forest
479 // over the pairs such that two pairs are connected iff the second pair
482 // Note that it only matters that both members of the second pair use some
483 // element of the first pair (to allow for splatting).
485 std::multimap<ValuePair, ValuePair> ConnectedPairs;
486 computeConnectedPairs(CandidatePairs, PairableInsts, ConnectedPairs);
487 if (ConnectedPairs.empty()) continue;
489 // Build the pairable-instruction dependency map
490 DenseSet<ValuePair> PairableInstUsers;
491 buildDepMap(BB, CandidatePairs, PairableInsts, PairableInstUsers);
493 // There is now a graph of the connected pairs. For each variable, pick
494 // the pairing with the largest tree meeting the depth requirement on at
495 // least one branch. Then select all pairings that are part of that tree
496 // and remove them from the list of available pairings and pairable
499 DenseMap<Value *, Value *> ChosenPairs;
500 choosePairs(CandidatePairs, PairableInsts, ConnectedPairs,
501 PairableInstUsers, ChosenPairs);
503 if (ChosenPairs.empty()) continue;
504 AllPairableInsts.insert(AllPairableInsts.end(), PairableInsts.begin(),
505 PairableInsts.end());
506 AllChosenPairs.insert(ChosenPairs.begin(), ChosenPairs.end());
507 } while (ShouldContinue);
509 if (AllChosenPairs.empty()) return false;
510 NumFusedOps += AllChosenPairs.size();
512 // A set of pairs has now been selected. It is now necessary to replace the
513 // paired instructions with vector instructions. For this procedure each
514 // operand must be replaced with a vector operand. This vector is formed
515 // by using build_vector on the old operands. The replaced values are then
516 // replaced with a vector_extract on the result. Subsequent optimization
517 // passes should coalesce the build/extract combinations.
519 fuseChosenPairs(BB, AllPairableInsts, AllChosenPairs);
523 // This function returns true if the provided instruction is capable of being
524 // fused into a vector instruction. This determination is based only on the
525 // type and other attributes of the instruction.
526 bool BBVectorize::isInstVectorizable(Instruction *I,
527 bool &IsSimpleLoadStore) {
528 IsSimpleLoadStore = false;
530 if (CallInst *C = dyn_cast<CallInst>(I)) {
531 if (!isVectorizableIntrinsic(C))
533 } else if (LoadInst *L = dyn_cast<LoadInst>(I)) {
534 // Vectorize simple loads if possbile:
535 IsSimpleLoadStore = L->isSimple();
536 if (!IsSimpleLoadStore || !Config.VectorizeMemOps)
538 } else if (StoreInst *S = dyn_cast<StoreInst>(I)) {
539 // Vectorize simple stores if possbile:
540 IsSimpleLoadStore = S->isSimple();
541 if (!IsSimpleLoadStore || !Config.VectorizeMemOps)
543 } else if (CastInst *C = dyn_cast<CastInst>(I)) {
544 // We can vectorize casts, but not casts of pointer types, etc.
545 if (!Config.VectorizeCasts)
548 Type *SrcTy = C->getSrcTy();
549 if (!SrcTy->isSingleValueType() || SrcTy->isPointerTy())
552 Type *DestTy = C->getDestTy();
553 if (!DestTy->isSingleValueType() || DestTy->isPointerTy())
555 } else if (!(I->isBinaryOp() || isa<ShuffleVectorInst>(I) ||
556 isa<ExtractElementInst>(I) || isa<InsertElementInst>(I))) {
560 // We can't vectorize memory operations without target data
561 if (TD == 0 && IsSimpleLoadStore)
565 if (isa<StoreInst>(I)) {
566 // For stores, it is the value type, not the pointer type that matters
567 // because the value is what will come from a vector register.
569 Value *IVal = cast<StoreInst>(I)->getValueOperand();
570 T1 = IVal->getType();
576 T2 = cast<CastInst>(I)->getSrcTy();
580 // Not every type can be vectorized...
581 if (!(VectorType::isValidElementType(T1) || T1->isVectorTy()) ||
582 !(VectorType::isValidElementType(T2) || T2->isVectorTy()))
585 if (!Config.VectorizeInts
586 && (T1->isIntOrIntVectorTy() || T2->isIntOrIntVectorTy()))
589 if (!Config.VectorizeFloats
590 && (T1->isFPOrFPVectorTy() || T2->isFPOrFPVectorTy()))
593 if (T1->getPrimitiveSizeInBits() > Config.VectorBits/2 ||
594 T2->getPrimitiveSizeInBits() > Config.VectorBits/2)
600 // This function returns true if the two provided instructions are compatible
601 // (meaning that they can be fused into a vector instruction). This assumes
602 // that I has already been determined to be vectorizable and that J is not
603 // in the use tree of I.
604 bool BBVectorize::areInstsCompatible(Instruction *I, Instruction *J,
605 bool IsSimpleLoadStore) {
606 DEBUG(if (DebugInstructionExamination) dbgs() << "BBV: looking at " << *I <<
607 " <-> " << *J << "\n");
609 // Loads and stores can be merged if they have different alignments,
610 // but are otherwise the same.
613 if ((LI = dyn_cast<LoadInst>(I)) && (LJ = dyn_cast<LoadInst>(J))) {
614 if (I->getType() != J->getType())
617 if (LI->getPointerOperand()->getType() !=
618 LJ->getPointerOperand()->getType() ||
619 LI->isVolatile() != LJ->isVolatile() ||
620 LI->getOrdering() != LJ->getOrdering() ||
621 LI->getSynchScope() != LJ->getSynchScope())
623 } else if ((SI = dyn_cast<StoreInst>(I)) && (SJ = dyn_cast<StoreInst>(J))) {
624 if (SI->getValueOperand()->getType() !=
625 SJ->getValueOperand()->getType() ||
626 SI->getPointerOperand()->getType() !=
627 SJ->getPointerOperand()->getType() ||
628 SI->isVolatile() != SJ->isVolatile() ||
629 SI->getOrdering() != SJ->getOrdering() ||
630 SI->getSynchScope() != SJ->getSynchScope())
632 } else if (!J->isSameOperationAs(I)) {
635 // FIXME: handle addsub-type operations!
637 if (IsSimpleLoadStore) {
639 unsigned IAlignment, JAlignment;
640 int64_t OffsetInElmts = 0;
641 if (getPairPtrInfo(I, J, IPtr, JPtr, IAlignment, JAlignment,
642 OffsetInElmts) && abs64(OffsetInElmts) == 1) {
643 if (Config.AlignedOnly) {
644 Type *aType = isa<StoreInst>(I) ?
645 cast<StoreInst>(I)->getValueOperand()->getType() : I->getType();
646 // An aligned load or store is possible only if the instruction
647 // with the lower offset has an alignment suitable for the
650 unsigned BottomAlignment = IAlignment;
651 if (OffsetInElmts < 0) BottomAlignment = JAlignment;
653 Type *VType = getVecTypeForPair(aType);
654 unsigned VecAlignment = TD->getPrefTypeAlignment(VType);
655 if (BottomAlignment < VecAlignment)
661 } else if (isa<ShuffleVectorInst>(I)) {
662 // Only merge two shuffles if they're both constant
663 return isa<Constant>(I->getOperand(2)) &&
664 isa<Constant>(J->getOperand(2));
665 // FIXME: We may want to vectorize non-constant shuffles also.
668 // The powi intrinsic is special because only the first argument is
669 // vectorized, the second arguments must be equal.
670 CallInst *CI = dyn_cast<CallInst>(I);
672 if (CI && (FI = CI->getCalledFunction()) &&
673 FI->getIntrinsicID() == Intrinsic::powi) {
675 Value *A1I = CI->getArgOperand(1),
676 *A1J = cast<CallInst>(J)->getArgOperand(1);
677 const SCEV *A1ISCEV = SE->getSCEV(A1I),
678 *A1JSCEV = SE->getSCEV(A1J);
679 return (A1ISCEV == A1JSCEV);
685 // Figure out whether or not J uses I and update the users and write-set
686 // structures associated with I. Specifically, Users represents the set of
687 // instructions that depend on I. WriteSet represents the set
688 // of memory locations that are dependent on I. If UpdateUsers is true,
689 // and J uses I, then Users is updated to contain J and WriteSet is updated
690 // to contain any memory locations to which J writes. The function returns
691 // true if J uses I. By default, alias analysis is used to determine
692 // whether J reads from memory that overlaps with a location in WriteSet.
693 // If LoadMoveSet is not null, then it is a previously-computed multimap
694 // where the key is the memory-based user instruction and the value is
695 // the instruction to be compared with I. So, if LoadMoveSet is provided,
696 // then the alias analysis is not used. This is necessary because this
697 // function is called during the process of moving instructions during
698 // vectorization and the results of the alias analysis are not stable during
700 bool BBVectorize::trackUsesOfI(DenseSet<Value *> &Users,
701 AliasSetTracker &WriteSet, Instruction *I,
702 Instruction *J, bool UpdateUsers,
703 std::multimap<Value *, Value *> *LoadMoveSet) {
706 // This instruction may already be marked as a user due, for example, to
707 // being a member of a selected pair.
712 for (User::op_iterator JU = J->op_begin(), JE = J->op_end();
715 if (I == V || Users.count(V)) {
720 if (!UsesI && J->mayReadFromMemory()) {
722 VPIteratorPair JPairRange = LoadMoveSet->equal_range(J);
723 UsesI = isSecondInIteratorPair<Value*>(I, JPairRange);
725 for (AliasSetTracker::iterator W = WriteSet.begin(),
726 WE = WriteSet.end(); W != WE; ++W) {
727 if (W->aliasesUnknownInst(J, *AA)) {
735 if (UsesI && UpdateUsers) {
736 if (J->mayWriteToMemory()) WriteSet.add(J);
743 // This function iterates over all instruction pairs in the provided
744 // basic block and collects all candidate pairs for vectorization.
745 bool BBVectorize::getCandidatePairs(BasicBlock &BB,
746 BasicBlock::iterator &Start,
747 std::multimap<Value *, Value *> &CandidatePairs,
748 std::vector<Value *> &PairableInsts) {
749 BasicBlock::iterator E = BB.end();
750 if (Start == E) return false;
752 bool ShouldContinue = false, IAfterStart = false;
753 for (BasicBlock::iterator I = Start++; I != E; ++I) {
754 if (I == Start) IAfterStart = true;
756 bool IsSimpleLoadStore;
757 if (!isInstVectorizable(I, IsSimpleLoadStore)) continue;
759 // Look for an instruction with which to pair instruction *I...
760 DenseSet<Value *> Users;
761 AliasSetTracker WriteSet(*AA);
762 bool JAfterStart = IAfterStart;
763 BasicBlock::iterator J = llvm::next(I);
764 for (unsigned ss = 0; J != E && ss <= Config.SearchLimit; ++J, ++ss) {
765 if (J == Start) JAfterStart = true;
767 // Determine if J uses I, if so, exit the loop.
768 bool UsesI = trackUsesOfI(Users, WriteSet, I, J, !Config.FastDep);
769 if (Config.FastDep) {
770 // Note: For this heuristic to be effective, independent operations
771 // must tend to be intermixed. This is likely to be true from some
772 // kinds of grouped loop unrolling (but not the generic LLVM pass),
773 // but otherwise may require some kind of reordering pass.
775 // When using fast dependency analysis,
776 // stop searching after first use:
782 // J does not use I, and comes before the first use of I, so it can be
783 // merged with I if the instructions are compatible.
784 if (!areInstsCompatible(I, J, IsSimpleLoadStore)) continue;
786 // J is a candidate for merging with I.
787 if (!PairableInsts.size() ||
788 PairableInsts[PairableInsts.size()-1] != I) {
789 PairableInsts.push_back(I);
792 CandidatePairs.insert(ValuePair(I, J));
794 // The next call to this function must start after the last instruction
795 // selected during this invocation.
797 Start = llvm::next(J);
798 IAfterStart = JAfterStart = false;
801 DEBUG(if (DebugCandidateSelection) dbgs() << "BBV: candidate pair "
802 << *I << " <-> " << *J << "\n");
804 // If we have already found too many pairs, break here and this function
805 // will be called again starting after the last instruction selected
806 // during this invocation.
807 if (PairableInsts.size() >= Config.MaxInsts) {
808 ShouldContinue = true;
817 DEBUG(dbgs() << "BBV: found " << PairableInsts.size()
818 << " instructions with candidate pairs\n");
820 return ShouldContinue;
823 // Finds candidate pairs connected to the pair P = <PI, PJ>. This means that
824 // it looks for pairs such that both members have an input which is an
825 // output of PI or PJ.
826 void BBVectorize::computePairsConnectedTo(
827 std::multimap<Value *, Value *> &CandidatePairs,
828 std::vector<Value *> &PairableInsts,
829 std::multimap<ValuePair, ValuePair> &ConnectedPairs,
831 // For each possible pairing for this variable, look at the uses of
832 // the first value...
833 for (Value::use_iterator I = P.first->use_begin(),
834 E = P.first->use_end(); I != E; ++I) {
835 VPIteratorPair IPairRange = CandidatePairs.equal_range(*I);
837 // For each use of the first variable, look for uses of the second
839 for (Value::use_iterator J = P.second->use_begin(),
840 E2 = P.second->use_end(); J != E2; ++J) {
841 VPIteratorPair JPairRange = CandidatePairs.equal_range(*J);
844 if (isSecondInIteratorPair<Value*>(*J, IPairRange))
845 ConnectedPairs.insert(VPPair(P, ValuePair(*I, *J)));
848 if (isSecondInIteratorPair<Value*>(*I, JPairRange))
849 ConnectedPairs.insert(VPPair(P, ValuePair(*J, *I)));
852 if (Config.SplatBreaksChain) continue;
853 // Look for cases where just the first value in the pair is used by
854 // both members of another pair (splatting).
855 for (Value::use_iterator J = P.first->use_begin(); J != E; ++J) {
856 if (isSecondInIteratorPair<Value*>(*J, IPairRange))
857 ConnectedPairs.insert(VPPair(P, ValuePair(*I, *J)));
861 if (Config.SplatBreaksChain) return;
862 // Look for cases where just the second value in the pair is used by
863 // both members of another pair (splatting).
864 for (Value::use_iterator I = P.second->use_begin(),
865 E = P.second->use_end(); I != E; ++I) {
866 VPIteratorPair IPairRange = CandidatePairs.equal_range(*I);
868 for (Value::use_iterator J = P.second->use_begin(); J != E; ++J) {
869 if (isSecondInIteratorPair<Value*>(*J, IPairRange))
870 ConnectedPairs.insert(VPPair(P, ValuePair(*I, *J)));
875 // This function figures out which pairs are connected. Two pairs are
876 // connected if some output of the first pair forms an input to both members
877 // of the second pair.
878 void BBVectorize::computeConnectedPairs(
879 std::multimap<Value *, Value *> &CandidatePairs,
880 std::vector<Value *> &PairableInsts,
881 std::multimap<ValuePair, ValuePair> &ConnectedPairs) {
883 for (std::vector<Value *>::iterator PI = PairableInsts.begin(),
884 PE = PairableInsts.end(); PI != PE; ++PI) {
885 VPIteratorPair choiceRange = CandidatePairs.equal_range(*PI);
887 for (std::multimap<Value *, Value *>::iterator P = choiceRange.first;
888 P != choiceRange.second; ++P)
889 computePairsConnectedTo(CandidatePairs, PairableInsts,
893 DEBUG(dbgs() << "BBV: found " << ConnectedPairs.size()
894 << " pair connections.\n");
897 // This function builds a set of use tuples such that <A, B> is in the set
898 // if B is in the use tree of A. If B is in the use tree of A, then B
899 // depends on the output of A.
900 void BBVectorize::buildDepMap(
902 std::multimap<Value *, Value *> &CandidatePairs,
903 std::vector<Value *> &PairableInsts,
904 DenseSet<ValuePair> &PairableInstUsers) {
905 DenseSet<Value *> IsInPair;
906 for (std::multimap<Value *, Value *>::iterator C = CandidatePairs.begin(),
907 E = CandidatePairs.end(); C != E; ++C) {
908 IsInPair.insert(C->first);
909 IsInPair.insert(C->second);
912 // Iterate through the basic block, recording all Users of each
913 // pairable instruction.
915 BasicBlock::iterator E = BB.end();
916 for (BasicBlock::iterator I = BB.getFirstInsertionPt(); I != E; ++I) {
917 if (IsInPair.find(I) == IsInPair.end()) continue;
919 DenseSet<Value *> Users;
920 AliasSetTracker WriteSet(*AA);
921 for (BasicBlock::iterator J = llvm::next(I); J != E; ++J)
922 (void) trackUsesOfI(Users, WriteSet, I, J);
924 for (DenseSet<Value *>::iterator U = Users.begin(), E = Users.end();
926 PairableInstUsers.insert(ValuePair(I, *U));
930 // Returns true if an input to pair P is an output of pair Q and also an
931 // input of pair Q is an output of pair P. If this is the case, then these
932 // two pairs cannot be simultaneously fused.
933 bool BBVectorize::pairsConflict(ValuePair P, ValuePair Q,
934 DenseSet<ValuePair> &PairableInstUsers,
935 std::multimap<ValuePair, ValuePair> *PairableInstUserMap) {
936 // Two pairs are in conflict if they are mutual Users of eachother.
937 bool QUsesP = PairableInstUsers.count(ValuePair(P.first, Q.first)) ||
938 PairableInstUsers.count(ValuePair(P.first, Q.second)) ||
939 PairableInstUsers.count(ValuePair(P.second, Q.first)) ||
940 PairableInstUsers.count(ValuePair(P.second, Q.second));
941 bool PUsesQ = PairableInstUsers.count(ValuePair(Q.first, P.first)) ||
942 PairableInstUsers.count(ValuePair(Q.first, P.second)) ||
943 PairableInstUsers.count(ValuePair(Q.second, P.first)) ||
944 PairableInstUsers.count(ValuePair(Q.second, P.second));
945 if (PairableInstUserMap) {
946 // FIXME: The expensive part of the cycle check is not so much the cycle
947 // check itself but this edge insertion procedure. This needs some
948 // profiling and probably a different data structure (same is true of
949 // most uses of std::multimap).
951 VPPIteratorPair QPairRange = PairableInstUserMap->equal_range(Q);
952 if (!isSecondInIteratorPair(P, QPairRange))
953 PairableInstUserMap->insert(VPPair(Q, P));
956 VPPIteratorPair PPairRange = PairableInstUserMap->equal_range(P);
957 if (!isSecondInIteratorPair(Q, PPairRange))
958 PairableInstUserMap->insert(VPPair(P, Q));
962 return (QUsesP && PUsesQ);
965 // This function walks the use graph of current pairs to see if, starting
966 // from P, the walk returns to P.
967 bool BBVectorize::pairWillFormCycle(ValuePair P,
968 std::multimap<ValuePair, ValuePair> &PairableInstUserMap,
969 DenseSet<ValuePair> &CurrentPairs) {
970 DEBUG(if (DebugCycleCheck)
971 dbgs() << "BBV: starting cycle check for : " << *P.first << " <-> "
972 << *P.second << "\n");
973 // A lookup table of visisted pairs is kept because the PairableInstUserMap
974 // contains non-direct associations.
975 DenseSet<ValuePair> Visited;
976 SmallVector<ValuePair, 32> Q;
977 // General depth-first post-order traversal:
980 ValuePair QTop = Q.pop_back_val();
981 Visited.insert(QTop);
983 DEBUG(if (DebugCycleCheck)
984 dbgs() << "BBV: cycle check visiting: " << *QTop.first << " <-> "
985 << *QTop.second << "\n");
986 VPPIteratorPair QPairRange = PairableInstUserMap.equal_range(QTop);
987 for (std::multimap<ValuePair, ValuePair>::iterator C = QPairRange.first;
988 C != QPairRange.second; ++C) {
989 if (C->second == P) {
991 << "BBV: rejected to prevent non-trivial cycle formation: "
992 << *C->first.first << " <-> " << *C->first.second << "\n");
996 if (CurrentPairs.count(C->second) && !Visited.count(C->second))
997 Q.push_back(C->second);
999 } while (!Q.empty());
1004 // This function builds the initial tree of connected pairs with the
1005 // pair J at the root.
1006 void BBVectorize::buildInitialTreeFor(
1007 std::multimap<Value *, Value *> &CandidatePairs,
1008 std::vector<Value *> &PairableInsts,
1009 std::multimap<ValuePair, ValuePair> &ConnectedPairs,
1010 DenseSet<ValuePair> &PairableInstUsers,
1011 DenseMap<Value *, Value *> &ChosenPairs,
1012 DenseMap<ValuePair, size_t> &Tree, ValuePair J) {
1013 // Each of these pairs is viewed as the root node of a Tree. The Tree
1014 // is then walked (depth-first). As this happens, we keep track of
1015 // the pairs that compose the Tree and the maximum depth of the Tree.
1016 SmallVector<ValuePairWithDepth, 32> Q;
1017 // General depth-first post-order traversal:
1018 Q.push_back(ValuePairWithDepth(J, getDepthFactor(J.first)));
1020 ValuePairWithDepth QTop = Q.back();
1022 // Push each child onto the queue:
1023 bool MoreChildren = false;
1024 size_t MaxChildDepth = QTop.second;
1025 VPPIteratorPair qtRange = ConnectedPairs.equal_range(QTop.first);
1026 for (std::multimap<ValuePair, ValuePair>::iterator k = qtRange.first;
1027 k != qtRange.second; ++k) {
1028 // Make sure that this child pair is still a candidate:
1029 bool IsStillCand = false;
1030 VPIteratorPair checkRange =
1031 CandidatePairs.equal_range(k->second.first);
1032 for (std::multimap<Value *, Value *>::iterator m = checkRange.first;
1033 m != checkRange.second; ++m) {
1034 if (m->second == k->second.second) {
1041 DenseMap<ValuePair, size_t>::iterator C = Tree.find(k->second);
1042 if (C == Tree.end()) {
1043 size_t d = getDepthFactor(k->second.first);
1044 Q.push_back(ValuePairWithDepth(k->second, QTop.second+d));
1045 MoreChildren = true;
1047 MaxChildDepth = std::max(MaxChildDepth, C->second);
1052 if (!MoreChildren) {
1053 // Record the current pair as part of the Tree:
1054 Tree.insert(ValuePairWithDepth(QTop.first, MaxChildDepth));
1057 } while (!Q.empty());
1060 // Given some initial tree, prune it by removing conflicting pairs (pairs
1061 // that cannot be simultaneously chosen for vectorization).
1062 void BBVectorize::pruneTreeFor(
1063 std::multimap<Value *, Value *> &CandidatePairs,
1064 std::vector<Value *> &PairableInsts,
1065 std::multimap<ValuePair, ValuePair> &ConnectedPairs,
1066 DenseSet<ValuePair> &PairableInstUsers,
1067 std::multimap<ValuePair, ValuePair> &PairableInstUserMap,
1068 DenseMap<Value *, Value *> &ChosenPairs,
1069 DenseMap<ValuePair, size_t> &Tree,
1070 DenseSet<ValuePair> &PrunedTree, ValuePair J,
1071 bool UseCycleCheck) {
1072 SmallVector<ValuePairWithDepth, 32> Q;
1073 // General depth-first post-order traversal:
1074 Q.push_back(ValuePairWithDepth(J, getDepthFactor(J.first)));
1076 ValuePairWithDepth QTop = Q.pop_back_val();
1077 PrunedTree.insert(QTop.first);
1079 // Visit each child, pruning as necessary...
1080 DenseMap<ValuePair, size_t> BestChildren;
1081 VPPIteratorPair QTopRange = ConnectedPairs.equal_range(QTop.first);
1082 for (std::multimap<ValuePair, ValuePair>::iterator K = QTopRange.first;
1083 K != QTopRange.second; ++K) {
1084 DenseMap<ValuePair, size_t>::iterator C = Tree.find(K->second);
1085 if (C == Tree.end()) continue;
1087 // This child is in the Tree, now we need to make sure it is the
1088 // best of any conflicting children. There could be multiple
1089 // conflicting children, so first, determine if we're keeping
1090 // this child, then delete conflicting children as necessary.
1092 // It is also necessary to guard against pairing-induced
1093 // dependencies. Consider instructions a .. x .. y .. b
1094 // such that (a,b) are to be fused and (x,y) are to be fused
1095 // but a is an input to x and b is an output from y. This
1096 // means that y cannot be moved after b but x must be moved
1097 // after b for (a,b) to be fused. In other words, after
1098 // fusing (a,b) we have y .. a/b .. x where y is an input
1099 // to a/b and x is an output to a/b: x and y can no longer
1100 // be legally fused. To prevent this condition, we must
1101 // make sure that a child pair added to the Tree is not
1102 // both an input and output of an already-selected pair.
1104 // Pairing-induced dependencies can also form from more complicated
1105 // cycles. The pair vs. pair conflicts are easy to check, and so
1106 // that is done explicitly for "fast rejection", and because for
1107 // child vs. child conflicts, we may prefer to keep the current
1108 // pair in preference to the already-selected child.
1109 DenseSet<ValuePair> CurrentPairs;
1112 for (DenseMap<ValuePair, size_t>::iterator C2
1113 = BestChildren.begin(), E2 = BestChildren.end();
1115 if (C2->first.first == C->first.first ||
1116 C2->first.first == C->first.second ||
1117 C2->first.second == C->first.first ||
1118 C2->first.second == C->first.second ||
1119 pairsConflict(C2->first, C->first, PairableInstUsers,
1120 UseCycleCheck ? &PairableInstUserMap : 0)) {
1121 if (C2->second >= C->second) {
1126 CurrentPairs.insert(C2->first);
1129 if (!CanAdd) continue;
1131 // Even worse, this child could conflict with another node already
1132 // selected for the Tree. If that is the case, ignore this child.
1133 for (DenseSet<ValuePair>::iterator T = PrunedTree.begin(),
1134 E2 = PrunedTree.end(); T != E2; ++T) {
1135 if (T->first == C->first.first ||
1136 T->first == C->first.second ||
1137 T->second == C->first.first ||
1138 T->second == C->first.second ||
1139 pairsConflict(*T, C->first, PairableInstUsers,
1140 UseCycleCheck ? &PairableInstUserMap : 0)) {
1145 CurrentPairs.insert(*T);
1147 if (!CanAdd) continue;
1149 // And check the queue too...
1150 for (SmallVector<ValuePairWithDepth, 32>::iterator C2 = Q.begin(),
1151 E2 = Q.end(); C2 != E2; ++C2) {
1152 if (C2->first.first == C->first.first ||
1153 C2->first.first == C->first.second ||
1154 C2->first.second == C->first.first ||
1155 C2->first.second == C->first.second ||
1156 pairsConflict(C2->first, C->first, PairableInstUsers,
1157 UseCycleCheck ? &PairableInstUserMap : 0)) {
1162 CurrentPairs.insert(C2->first);
1164 if (!CanAdd) continue;
1166 // Last but not least, check for a conflict with any of the
1167 // already-chosen pairs.
1168 for (DenseMap<Value *, Value *>::iterator C2 =
1169 ChosenPairs.begin(), E2 = ChosenPairs.end();
1171 if (pairsConflict(*C2, C->first, PairableInstUsers,
1172 UseCycleCheck ? &PairableInstUserMap : 0)) {
1177 CurrentPairs.insert(*C2);
1179 if (!CanAdd) continue;
1181 // To check for non-trivial cycles formed by the addition of the
1182 // current pair we've formed a list of all relevant pairs, now use a
1183 // graph walk to check for a cycle. We start from the current pair and
1184 // walk the use tree to see if we again reach the current pair. If we
1185 // do, then the current pair is rejected.
1187 // FIXME: It may be more efficient to use a topological-ordering
1188 // algorithm to improve the cycle check. This should be investigated.
1189 if (UseCycleCheck &&
1190 pairWillFormCycle(C->first, PairableInstUserMap, CurrentPairs))
1193 // This child can be added, but we may have chosen it in preference
1194 // to an already-selected child. Check for this here, and if a
1195 // conflict is found, then remove the previously-selected child
1196 // before adding this one in its place.
1197 for (DenseMap<ValuePair, size_t>::iterator C2
1198 = BestChildren.begin(); C2 != BestChildren.end();) {
1199 if (C2->first.first == C->first.first ||
1200 C2->first.first == C->first.second ||
1201 C2->first.second == C->first.first ||
1202 C2->first.second == C->first.second ||
1203 pairsConflict(C2->first, C->first, PairableInstUsers))
1204 BestChildren.erase(C2++);
1209 BestChildren.insert(ValuePairWithDepth(C->first, C->second));
1212 for (DenseMap<ValuePair, size_t>::iterator C
1213 = BestChildren.begin(), E2 = BestChildren.end();
1215 size_t DepthF = getDepthFactor(C->first.first);
1216 Q.push_back(ValuePairWithDepth(C->first, QTop.second+DepthF));
1218 } while (!Q.empty());
1221 // This function finds the best tree of mututally-compatible connected
1222 // pairs, given the choice of root pairs as an iterator range.
1223 void BBVectorize::findBestTreeFor(
1224 std::multimap<Value *, Value *> &CandidatePairs,
1225 std::vector<Value *> &PairableInsts,
1226 std::multimap<ValuePair, ValuePair> &ConnectedPairs,
1227 DenseSet<ValuePair> &PairableInstUsers,
1228 std::multimap<ValuePair, ValuePair> &PairableInstUserMap,
1229 DenseMap<Value *, Value *> &ChosenPairs,
1230 DenseSet<ValuePair> &BestTree, size_t &BestMaxDepth,
1231 size_t &BestEffSize, VPIteratorPair ChoiceRange,
1232 bool UseCycleCheck) {
1233 for (std::multimap<Value *, Value *>::iterator J = ChoiceRange.first;
1234 J != ChoiceRange.second; ++J) {
1236 // Before going any further, make sure that this pair does not
1237 // conflict with any already-selected pairs (see comment below
1238 // near the Tree pruning for more details).
1239 DenseSet<ValuePair> ChosenPairSet;
1240 bool DoesConflict = false;
1241 for (DenseMap<Value *, Value *>::iterator C = ChosenPairs.begin(),
1242 E = ChosenPairs.end(); C != E; ++C) {
1243 if (pairsConflict(*C, *J, PairableInstUsers,
1244 UseCycleCheck ? &PairableInstUserMap : 0)) {
1245 DoesConflict = true;
1249 ChosenPairSet.insert(*C);
1251 if (DoesConflict) continue;
1253 if (UseCycleCheck &&
1254 pairWillFormCycle(*J, PairableInstUserMap, ChosenPairSet))
1257 DenseMap<ValuePair, size_t> Tree;
1258 buildInitialTreeFor(CandidatePairs, PairableInsts, ConnectedPairs,
1259 PairableInstUsers, ChosenPairs, Tree, *J);
1261 // Because we'll keep the child with the largest depth, the largest
1262 // depth is still the same in the unpruned Tree.
1263 size_t MaxDepth = Tree.lookup(*J);
1265 DEBUG(if (DebugPairSelection) dbgs() << "BBV: found Tree for pair {"
1266 << *J->first << " <-> " << *J->second << "} of depth " <<
1267 MaxDepth << " and size " << Tree.size() << "\n");
1269 // At this point the Tree has been constructed, but, may contain
1270 // contradictory children (meaning that different children of
1271 // some tree node may be attempting to fuse the same instruction).
1272 // So now we walk the tree again, in the case of a conflict,
1273 // keep only the child with the largest depth. To break a tie,
1274 // favor the first child.
1276 DenseSet<ValuePair> PrunedTree;
1277 pruneTreeFor(CandidatePairs, PairableInsts, ConnectedPairs,
1278 PairableInstUsers, PairableInstUserMap, ChosenPairs, Tree,
1279 PrunedTree, *J, UseCycleCheck);
1282 for (DenseSet<ValuePair>::iterator S = PrunedTree.begin(),
1283 E = PrunedTree.end(); S != E; ++S)
1284 EffSize += getDepthFactor(S->first);
1286 DEBUG(if (DebugPairSelection)
1287 dbgs() << "BBV: found pruned Tree for pair {"
1288 << *J->first << " <-> " << *J->second << "} of depth " <<
1289 MaxDepth << " and size " << PrunedTree.size() <<
1290 " (effective size: " << EffSize << ")\n");
1291 if (MaxDepth >= Config.ReqChainDepth && EffSize > BestEffSize) {
1292 BestMaxDepth = MaxDepth;
1293 BestEffSize = EffSize;
1294 BestTree = PrunedTree;
1299 // Given the list of candidate pairs, this function selects those
1300 // that will be fused into vector instructions.
1301 void BBVectorize::choosePairs(
1302 std::multimap<Value *, Value *> &CandidatePairs,
1303 std::vector<Value *> &PairableInsts,
1304 std::multimap<ValuePair, ValuePair> &ConnectedPairs,
1305 DenseSet<ValuePair> &PairableInstUsers,
1306 DenseMap<Value *, Value *>& ChosenPairs) {
1307 bool UseCycleCheck =
1308 CandidatePairs.size() <= Config.MaxCandPairsForCycleCheck;
1309 std::multimap<ValuePair, ValuePair> PairableInstUserMap;
1310 for (std::vector<Value *>::iterator I = PairableInsts.begin(),
1311 E = PairableInsts.end(); I != E; ++I) {
1312 // The number of possible pairings for this variable:
1313 size_t NumChoices = CandidatePairs.count(*I);
1314 if (!NumChoices) continue;
1316 VPIteratorPair ChoiceRange = CandidatePairs.equal_range(*I);
1318 // The best pair to choose and its tree:
1319 size_t BestMaxDepth = 0, BestEffSize = 0;
1320 DenseSet<ValuePair> BestTree;
1321 findBestTreeFor(CandidatePairs, PairableInsts, ConnectedPairs,
1322 PairableInstUsers, PairableInstUserMap, ChosenPairs,
1323 BestTree, BestMaxDepth, BestEffSize, ChoiceRange,
1326 // A tree has been chosen (or not) at this point. If no tree was
1327 // chosen, then this instruction, I, cannot be paired (and is no longer
1330 DEBUG(if (BestTree.size() > 0)
1331 dbgs() << "BBV: selected pairs in the best tree for: "
1332 << *cast<Instruction>(*I) << "\n");
1334 for (DenseSet<ValuePair>::iterator S = BestTree.begin(),
1335 SE2 = BestTree.end(); S != SE2; ++S) {
1336 // Insert the members of this tree into the list of chosen pairs.
1337 ChosenPairs.insert(ValuePair(S->first, S->second));
1338 DEBUG(dbgs() << "BBV: selected pair: " << *S->first << " <-> " <<
1339 *S->second << "\n");
1341 // Remove all candidate pairs that have values in the chosen tree.
1342 for (std::multimap<Value *, Value *>::iterator K =
1343 CandidatePairs.begin(); K != CandidatePairs.end();) {
1344 if (K->first == S->first || K->second == S->first ||
1345 K->second == S->second || K->first == S->second) {
1346 // Don't remove the actual pair chosen so that it can be used
1347 // in subsequent tree selections.
1348 if (!(K->first == S->first && K->second == S->second))
1349 CandidatePairs.erase(K++);
1359 DEBUG(dbgs() << "BBV: selected " << ChosenPairs.size() << " pairs.\n");
1362 std::string getReplacementName(Instruction *I, bool IsInput, unsigned o,
1367 return (I->getName() + (IsInput ? ".v.i" : ".v.r") + utostr(o) +
1368 (n > 0 ? "." + utostr(n) : "")).str();
1371 // Returns the value that is to be used as the pointer input to the vector
1372 // instruction that fuses I with J.
1373 Value *BBVectorize::getReplacementPointerInput(LLVMContext& Context,
1374 Instruction *I, Instruction *J, unsigned o,
1375 bool &FlipMemInputs) {
1377 unsigned IAlignment, JAlignment;
1378 int64_t OffsetInElmts;
1379 (void) getPairPtrInfo(I, J, IPtr, JPtr, IAlignment, JAlignment,
1382 // The pointer value is taken to be the one with the lowest offset.
1384 if (OffsetInElmts > 0) {
1387 FlipMemInputs = true;
1391 Type *ArgType = cast<PointerType>(IPtr->getType())->getElementType();
1392 Type *VArgType = getVecTypeForPair(ArgType);
1393 Type *VArgPtrType = PointerType::get(VArgType,
1394 cast<PointerType>(IPtr->getType())->getAddressSpace());
1395 return new BitCastInst(VPtr, VArgPtrType, getReplacementName(I, true, o),
1396 /* insert before */ FlipMemInputs ? J : I);
1399 void BBVectorize::fillNewShuffleMask(LLVMContext& Context, Instruction *J,
1400 unsigned NumElem, unsigned MaskOffset, unsigned NumInElem,
1401 unsigned IdxOffset, std::vector<Constant*> &Mask) {
1402 for (unsigned v = 0; v < NumElem/2; ++v) {
1403 int m = cast<ShuffleVectorInst>(J)->getMaskValue(v);
1405 Mask[v+MaskOffset] = UndefValue::get(Type::getInt32Ty(Context));
1407 unsigned mm = m + (int) IdxOffset;
1408 if (m >= (int) NumInElem)
1409 mm += (int) NumInElem;
1411 Mask[v+MaskOffset] =
1412 ConstantInt::get(Type::getInt32Ty(Context), mm);
1417 // Returns the value that is to be used as the vector-shuffle mask to the
1418 // vector instruction that fuses I with J.
1419 Value *BBVectorize::getReplacementShuffleMask(LLVMContext& Context,
1420 Instruction *I, Instruction *J) {
1421 // This is the shuffle mask. We need to append the second
1422 // mask to the first, and the numbers need to be adjusted.
1424 Type *ArgType = I->getType();
1425 Type *VArgType = getVecTypeForPair(ArgType);
1427 // Get the total number of elements in the fused vector type.
1428 // By definition, this must equal the number of elements in
1430 unsigned NumElem = cast<VectorType>(VArgType)->getNumElements();
1431 std::vector<Constant*> Mask(NumElem);
1433 Type *OpType = I->getOperand(0)->getType();
1434 unsigned NumInElem = cast<VectorType>(OpType)->getNumElements();
1436 // For the mask from the first pair...
1437 fillNewShuffleMask(Context, I, NumElem, 0, NumInElem, 0, Mask);
1439 // For the mask from the second pair...
1440 fillNewShuffleMask(Context, J, NumElem, NumElem/2, NumInElem, NumInElem,
1443 return ConstantVector::get(Mask);
1446 // Returns the value to be used as the specified operand of the vector
1447 // instruction that fuses I with J.
1448 Value *BBVectorize::getReplacementInput(LLVMContext& Context, Instruction *I,
1449 Instruction *J, unsigned o, bool FlipMemInputs) {
1450 Value *CV0 = ConstantInt::get(Type::getInt32Ty(Context), 0);
1451 Value *CV1 = ConstantInt::get(Type::getInt32Ty(Context), 1);
1453 // Compute the fused vector type for this operand
1454 Type *ArgType = I->getOperand(o)->getType();
1455 VectorType *VArgType = getVecTypeForPair(ArgType);
1457 Instruction *L = I, *H = J;
1458 if (FlipMemInputs) {
1463 if (ArgType->isVectorTy()) {
1464 unsigned numElem = cast<VectorType>(VArgType)->getNumElements();
1465 std::vector<Constant*> Mask(numElem);
1466 for (unsigned v = 0; v < numElem; ++v)
1467 Mask[v] = ConstantInt::get(Type::getInt32Ty(Context), v);
1469 Instruction *BV = new ShuffleVectorInst(L->getOperand(o),
1471 ConstantVector::get(Mask),
1472 getReplacementName(I, true, o));
1473 BV->insertBefore(J);
1477 // If these two inputs are the output of another vector instruction,
1478 // then we should use that output directly. It might be necessary to
1479 // permute it first. [When pairings are fused recursively, you can
1480 // end up with cases where a large vector is decomposed into scalars
1481 // using extractelement instructions, then built into size-2
1482 // vectors using insertelement and the into larger vectors using
1483 // shuffles. InstCombine does not simplify all of these cases well,
1484 // and so we make sure that shuffles are generated here when possible.
1485 ExtractElementInst *LEE
1486 = dyn_cast<ExtractElementInst>(L->getOperand(o));
1487 ExtractElementInst *HEE
1488 = dyn_cast<ExtractElementInst>(H->getOperand(o));
1491 LEE->getOperand(0)->getType() == HEE->getOperand(0)->getType()) {
1492 VectorType *EEType = cast<VectorType>(LEE->getOperand(0)->getType());
1493 unsigned LowIndx = cast<ConstantInt>(LEE->getOperand(1))->getZExtValue();
1494 unsigned HighIndx = cast<ConstantInt>(HEE->getOperand(1))->getZExtValue();
1495 if (LEE->getOperand(0) == HEE->getOperand(0)) {
1496 if (LowIndx == 0 && HighIndx == 1)
1497 return LEE->getOperand(0);
1499 std::vector<Constant*> Mask(2);
1500 Mask[0] = ConstantInt::get(Type::getInt32Ty(Context), LowIndx);
1501 Mask[1] = ConstantInt::get(Type::getInt32Ty(Context), HighIndx);
1503 Instruction *BV = new ShuffleVectorInst(LEE->getOperand(0),
1504 UndefValue::get(EEType),
1505 ConstantVector::get(Mask),
1506 getReplacementName(I, true, o));
1507 BV->insertBefore(J);
1511 std::vector<Constant*> Mask(2);
1512 HighIndx += EEType->getNumElements();
1513 Mask[0] = ConstantInt::get(Type::getInt32Ty(Context), LowIndx);
1514 Mask[1] = ConstantInt::get(Type::getInt32Ty(Context), HighIndx);
1516 Instruction *BV = new ShuffleVectorInst(LEE->getOperand(0),
1518 ConstantVector::get(Mask),
1519 getReplacementName(I, true, o));
1520 BV->insertBefore(J);
1524 Instruction *BV1 = InsertElementInst::Create(
1525 UndefValue::get(VArgType),
1526 L->getOperand(o), CV0,
1527 getReplacementName(I, true, o, 1));
1528 BV1->insertBefore(I);
1529 Instruction *BV2 = InsertElementInst::Create(BV1, H->getOperand(o),
1531 getReplacementName(I, true, o, 2));
1532 BV2->insertBefore(J);
1536 // This function creates an array of values that will be used as the inputs
1537 // to the vector instruction that fuses I with J.
1538 void BBVectorize::getReplacementInputsForPair(LLVMContext& Context,
1539 Instruction *I, Instruction *J,
1540 SmallVector<Value *, 3> &ReplacedOperands,
1541 bool &FlipMemInputs) {
1542 FlipMemInputs = false;
1543 unsigned NumOperands = I->getNumOperands();
1545 for (unsigned p = 0, o = NumOperands-1; p < NumOperands; ++p, --o) {
1546 // Iterate backward so that we look at the store pointer
1547 // first and know whether or not we need to flip the inputs.
1549 if (isa<LoadInst>(I) || (o == 1 && isa<StoreInst>(I))) {
1550 // This is the pointer for a load/store instruction.
1551 ReplacedOperands[o] = getReplacementPointerInput(Context, I, J, o,
1554 } else if (isa<CallInst>(I)) {
1555 Function *F = cast<CallInst>(I)->getCalledFunction();
1556 unsigned IID = F->getIntrinsicID();
1557 if (o == NumOperands-1) {
1558 BasicBlock &BB = *I->getParent();
1560 Module *M = BB.getParent()->getParent();
1561 Type *ArgType = I->getType();
1562 Type *VArgType = getVecTypeForPair(ArgType);
1564 // FIXME: is it safe to do this here?
1565 ReplacedOperands[o] = Intrinsic::getDeclaration(M,
1566 (Intrinsic::ID) IID, VArgType);
1568 } else if (IID == Intrinsic::powi && o == 1) {
1569 // The second argument of powi is a single integer and we've already
1570 // checked that both arguments are equal. As a result, we just keep
1571 // I's second argument.
1572 ReplacedOperands[o] = I->getOperand(o);
1575 } else if (isa<ShuffleVectorInst>(I) && o == NumOperands-1) {
1576 ReplacedOperands[o] = getReplacementShuffleMask(Context, I, J);
1580 ReplacedOperands[o] =
1581 getReplacementInput(Context, I, J, o, FlipMemInputs);
1585 // This function creates two values that represent the outputs of the
1586 // original I and J instructions. These are generally vector shuffles
1587 // or extracts. In many cases, these will end up being unused and, thus,
1588 // eliminated by later passes.
1589 void BBVectorize::replaceOutputsOfPair(LLVMContext& Context, Instruction *I,
1590 Instruction *J, Instruction *K,
1591 Instruction *&InsertionPt,
1592 Instruction *&K1, Instruction *&K2,
1593 bool &FlipMemInputs) {
1594 Value *CV0 = ConstantInt::get(Type::getInt32Ty(Context), 0);
1595 Value *CV1 = ConstantInt::get(Type::getInt32Ty(Context), 1);
1597 if (isa<StoreInst>(I)) {
1598 AA->replaceWithNewValue(I, K);
1599 AA->replaceWithNewValue(J, K);
1601 Type *IType = I->getType();
1602 Type *VType = getVecTypeForPair(IType);
1604 if (IType->isVectorTy()) {
1605 unsigned numElem = cast<VectorType>(IType)->getNumElements();
1606 std::vector<Constant*> Mask1(numElem), Mask2(numElem);
1607 for (unsigned v = 0; v < numElem; ++v) {
1608 Mask1[v] = ConstantInt::get(Type::getInt32Ty(Context), v);
1609 Mask2[v] = ConstantInt::get(Type::getInt32Ty(Context), numElem+v);
1612 K1 = new ShuffleVectorInst(K, UndefValue::get(VType),
1613 ConstantVector::get(
1614 FlipMemInputs ? Mask2 : Mask1),
1615 getReplacementName(K, false, 1));
1616 K2 = new ShuffleVectorInst(K, UndefValue::get(VType),
1617 ConstantVector::get(
1618 FlipMemInputs ? Mask1 : Mask2),
1619 getReplacementName(K, false, 2));
1621 K1 = ExtractElementInst::Create(K, FlipMemInputs ? CV1 : CV0,
1622 getReplacementName(K, false, 1));
1623 K2 = ExtractElementInst::Create(K, FlipMemInputs ? CV0 : CV1,
1624 getReplacementName(K, false, 2));
1628 K2->insertAfter(K1);
1633 // Move all uses of the function I (including pairing-induced uses) after J.
1634 bool BBVectorize::canMoveUsesOfIAfterJ(BasicBlock &BB,
1635 std::multimap<Value *, Value *> &LoadMoveSet,
1636 Instruction *I, Instruction *J) {
1637 // Skip to the first instruction past I.
1638 BasicBlock::iterator L = llvm::next(BasicBlock::iterator(I));
1640 DenseSet<Value *> Users;
1641 AliasSetTracker WriteSet(*AA);
1642 for (; cast<Instruction>(L) != J; ++L)
1643 (void) trackUsesOfI(Users, WriteSet, I, L, true, &LoadMoveSet);
1645 assert(cast<Instruction>(L) == J &&
1646 "Tracking has not proceeded far enough to check for dependencies");
1647 // If J is now in the use set of I, then trackUsesOfI will return true
1648 // and we have a dependency cycle (and the fusing operation must abort).
1649 return !trackUsesOfI(Users, WriteSet, I, J, true, &LoadMoveSet);
1652 // Move all uses of the function I (including pairing-induced uses) after J.
1653 void BBVectorize::moveUsesOfIAfterJ(BasicBlock &BB,
1654 std::multimap<Value *, Value *> &LoadMoveSet,
1655 Instruction *&InsertionPt,
1656 Instruction *I, Instruction *J) {
1657 // Skip to the first instruction past I.
1658 BasicBlock::iterator L = llvm::next(BasicBlock::iterator(I));
1660 DenseSet<Value *> Users;
1661 AliasSetTracker WriteSet(*AA);
1662 for (; cast<Instruction>(L) != J;) {
1663 if (trackUsesOfI(Users, WriteSet, I, L, true, &LoadMoveSet)) {
1664 // Move this instruction
1665 Instruction *InstToMove = L; ++L;
1667 DEBUG(dbgs() << "BBV: moving: " << *InstToMove <<
1668 " to after " << *InsertionPt << "\n");
1669 InstToMove->removeFromParent();
1670 InstToMove->insertAfter(InsertionPt);
1671 InsertionPt = InstToMove;
1678 // Collect all load instruction that are in the move set of a given first
1679 // pair member. These loads depend on the first instruction, I, and so need
1680 // to be moved after J (the second instruction) when the pair is fused.
1681 void BBVectorize::collectPairLoadMoveSet(BasicBlock &BB,
1682 DenseMap<Value *, Value *> &ChosenPairs,
1683 std::multimap<Value *, Value *> &LoadMoveSet,
1685 // Skip to the first instruction past I.
1686 BasicBlock::iterator L = llvm::next(BasicBlock::iterator(I));
1688 DenseSet<Value *> Users;
1689 AliasSetTracker WriteSet(*AA);
1691 // Note: We cannot end the loop when we reach J because J could be moved
1692 // farther down the use chain by another instruction pairing. Also, J
1693 // could be before I if this is an inverted input.
1694 for (BasicBlock::iterator E = BB.end(); cast<Instruction>(L) != E; ++L) {
1695 if (trackUsesOfI(Users, WriteSet, I, L)) {
1696 if (L->mayReadFromMemory())
1697 LoadMoveSet.insert(ValuePair(L, I));
1702 // In cases where both load/stores and the computation of their pointers
1703 // are chosen for vectorization, we can end up in a situation where the
1704 // aliasing analysis starts returning different query results as the
1705 // process of fusing instruction pairs continues. Because the algorithm
1706 // relies on finding the same use trees here as were found earlier, we'll
1707 // need to precompute the necessary aliasing information here and then
1708 // manually update it during the fusion process.
1709 void BBVectorize::collectLoadMoveSet(BasicBlock &BB,
1710 std::vector<Value *> &PairableInsts,
1711 DenseMap<Value *, Value *> &ChosenPairs,
1712 std::multimap<Value *, Value *> &LoadMoveSet) {
1713 for (std::vector<Value *>::iterator PI = PairableInsts.begin(),
1714 PIE = PairableInsts.end(); PI != PIE; ++PI) {
1715 DenseMap<Value *, Value *>::iterator P = ChosenPairs.find(*PI);
1716 if (P == ChosenPairs.end()) continue;
1718 Instruction *I = cast<Instruction>(P->first);
1719 collectPairLoadMoveSet(BB, ChosenPairs, LoadMoveSet, I);
1723 // This function fuses the chosen instruction pairs into vector instructions,
1724 // taking care preserve any needed scalar outputs and, then, it reorders the
1725 // remaining instructions as needed (users of the first member of the pair
1726 // need to be moved to after the location of the second member of the pair
1727 // because the vector instruction is inserted in the location of the pair's
1729 void BBVectorize::fuseChosenPairs(BasicBlock &BB,
1730 std::vector<Value *> &PairableInsts,
1731 DenseMap<Value *, Value *> &ChosenPairs) {
1732 LLVMContext& Context = BB.getContext();
1734 // During the vectorization process, the order of the pairs to be fused
1735 // could be flipped. So we'll add each pair, flipped, into the ChosenPairs
1736 // list. After a pair is fused, the flipped pair is removed from the list.
1737 std::vector<ValuePair> FlippedPairs;
1738 FlippedPairs.reserve(ChosenPairs.size());
1739 for (DenseMap<Value *, Value *>::iterator P = ChosenPairs.begin(),
1740 E = ChosenPairs.end(); P != E; ++P)
1741 FlippedPairs.push_back(ValuePair(P->second, P->first));
1742 for (std::vector<ValuePair>::iterator P = FlippedPairs.begin(),
1743 E = FlippedPairs.end(); P != E; ++P)
1744 ChosenPairs.insert(*P);
1746 std::multimap<Value *, Value *> LoadMoveSet;
1747 collectLoadMoveSet(BB, PairableInsts, ChosenPairs, LoadMoveSet);
1749 DEBUG(dbgs() << "BBV: initial: \n" << BB << "\n");
1751 for (BasicBlock::iterator PI = BB.getFirstInsertionPt(); PI != BB.end();) {
1752 DenseMap<Value *, Value *>::iterator P = ChosenPairs.find(PI);
1753 if (P == ChosenPairs.end()) {
1758 if (getDepthFactor(P->first) == 0) {
1759 // These instructions are not really fused, but are tracked as though
1760 // they are. Any case in which it would be interesting to fuse them
1761 // will be taken care of by InstCombine.
1767 Instruction *I = cast<Instruction>(P->first),
1768 *J = cast<Instruction>(P->second);
1770 DEBUG(dbgs() << "BBV: fusing: " << *I <<
1771 " <-> " << *J << "\n");
1773 // Remove the pair and flipped pair from the list.
1774 DenseMap<Value *, Value *>::iterator FP = ChosenPairs.find(P->second);
1775 assert(FP != ChosenPairs.end() && "Flipped pair not found in list");
1776 ChosenPairs.erase(FP);
1777 ChosenPairs.erase(P);
1779 if (!canMoveUsesOfIAfterJ(BB, LoadMoveSet, I, J)) {
1780 DEBUG(dbgs() << "BBV: fusion of: " << *I <<
1782 " aborted because of non-trivial dependency cycle\n");
1789 unsigned NumOperands = I->getNumOperands();
1790 SmallVector<Value *, 3> ReplacedOperands(NumOperands);
1791 getReplacementInputsForPair(Context, I, J, ReplacedOperands,
1794 // Make a copy of the original operation, change its type to the vector
1795 // type and replace its operands with the vector operands.
1796 Instruction *K = I->clone();
1797 if (I->hasName()) K->takeName(I);
1799 if (!isa<StoreInst>(K))
1800 K->mutateType(getVecTypeForPair(I->getType()));
1802 for (unsigned o = 0; o < NumOperands; ++o)
1803 K->setOperand(o, ReplacedOperands[o]);
1805 // If we've flipped the memory inputs, make sure that we take the correct
1807 if (FlipMemInputs) {
1808 if (isa<StoreInst>(K))
1809 cast<StoreInst>(K)->setAlignment(cast<StoreInst>(J)->getAlignment());
1811 cast<LoadInst>(K)->setAlignment(cast<LoadInst>(J)->getAlignment());
1816 // Instruction insertion point:
1817 Instruction *InsertionPt = K;
1818 Instruction *K1 = 0, *K2 = 0;
1819 replaceOutputsOfPair(Context, I, J, K, InsertionPt, K1, K2,
1822 // The use tree of the first original instruction must be moved to after
1823 // the location of the second instruction. The entire use tree of the
1824 // first instruction is disjoint from the input tree of the second
1825 // (by definition), and so commutes with it.
1827 moveUsesOfIAfterJ(BB, LoadMoveSet, InsertionPt, I, J);
1829 if (!isa<StoreInst>(I)) {
1830 I->replaceAllUsesWith(K1);
1831 J->replaceAllUsesWith(K2);
1832 AA->replaceWithNewValue(I, K1);
1833 AA->replaceWithNewValue(J, K2);
1836 // Instructions that may read from memory may be in the load move set.
1837 // Once an instruction is fused, we no longer need its move set, and so
1838 // the values of the map never need to be updated. However, when a load
1839 // is fused, we need to merge the entries from both instructions in the
1840 // pair in case those instructions were in the move set of some other
1841 // yet-to-be-fused pair. The loads in question are the keys of the map.
1842 if (I->mayReadFromMemory()) {
1843 std::vector<ValuePair> NewSetMembers;
1844 VPIteratorPair IPairRange = LoadMoveSet.equal_range(I);
1845 VPIteratorPair JPairRange = LoadMoveSet.equal_range(J);
1846 for (std::multimap<Value *, Value *>::iterator N = IPairRange.first;
1847 N != IPairRange.second; ++N)
1848 NewSetMembers.push_back(ValuePair(K, N->second));
1849 for (std::multimap<Value *, Value *>::iterator N = JPairRange.first;
1850 N != JPairRange.second; ++N)
1851 NewSetMembers.push_back(ValuePair(K, N->second));
1852 for (std::vector<ValuePair>::iterator A = NewSetMembers.begin(),
1853 AE = NewSetMembers.end(); A != AE; ++A)
1854 LoadMoveSet.insert(*A);
1857 // Before removing I, set the iterator to the next instruction.
1858 PI = llvm::next(BasicBlock::iterator(I));
1859 if (cast<Instruction>(PI) == J)
1864 I->eraseFromParent();
1865 J->eraseFromParent();
1868 DEBUG(dbgs() << "BBV: final: \n" << BB << "\n");
1872 char BBVectorize::ID = 0;
1873 static const char bb_vectorize_name[] = "Basic-Block Vectorization";
1874 INITIALIZE_PASS_BEGIN(BBVectorize, BBV_NAME, bb_vectorize_name, false, false)
1875 INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
1876 INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
1877 INITIALIZE_PASS_END(BBVectorize, BBV_NAME, bb_vectorize_name, false, false)
1879 BasicBlockPass *llvm::createBBVectorizePass(const VectorizeConfig &C) {
1880 return new BBVectorize(C);
1884 llvm::vectorizeBasicBlock(Pass *P, BasicBlock &BB, const VectorizeConfig &C) {
1885 BBVectorize BBVectorizer(P, C);
1886 return BBVectorizer.vectorizeBB(BB);
1889 //===----------------------------------------------------------------------===//
1890 VectorizeConfig::VectorizeConfig() {
1891 VectorBits = ::VectorBits;
1892 VectorizeInts = !::NoInts;
1893 VectorizeFloats = !::NoFloats;
1894 VectorizeCasts = !::NoCasts;
1895 VectorizeMath = !::NoMath;
1896 VectorizeFMA = !::NoFMA;
1897 VectorizeMemOps = !::NoMemOps;
1898 AlignedOnly = ::AlignedOnly;
1899 ReqChainDepth= ::ReqChainDepth;
1900 SearchLimit = ::SearchLimit;
1901 MaxCandPairsForCycleCheck = ::MaxCandPairsForCycleCheck;
1902 SplatBreaksChain = ::SplatBreaksChain;
1903 MaxInsts = ::MaxInsts;
1904 MaxIter = ::MaxIter;
1905 NoMemOpBoost = ::NoMemOpBoost;
1906 FastDep = ::FastDep;