1 //===--- Scalarizer.cpp - Scalarize vector operations ---------------------===// 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 converts vector operations into scalar operations, in order 11 // to expose optimization opportunities on the individual scalar operations. 12 // It is mainly intended for targets that do not have vector units, but it 13 // may also be useful for revectorizing code to different vector widths. 14 // 15 //===----------------------------------------------------------------------===// 16 17 #include "llvm/Transforms/Scalar.h" 18 #include "llvm/ADT/STLExtras.h" 19 #include "llvm/IR/IRBuilder.h" 20 #include "llvm/IR/InstVisitor.h" 21 #include "llvm/Pass.h" 22 #include "llvm/Transforms/Utils/BasicBlockUtils.h" 23 24 using namespace llvm; 25 26 #define DEBUG_TYPE "scalarizer" 27 28 namespace { 29 // Used to store the scattered form of a vector. 30 typedef SmallVector<Value *, 8> ValueVector; 31 32 // Used to map a vector Value to its scattered form. We use std::map 33 // because we want iterators to persist across insertion and because the 34 // values are relatively large. 35 typedef std::map<Value *, ValueVector> ScatterMap; 36 37 // Lists Instructions that have been replaced with scalar implementations, 38 // along with a pointer to their scattered forms. 39 typedef SmallVector<std::pair<Instruction *, ValueVector *>, 16> GatherList; 40 41 // Provides a very limited vector-like interface for lazily accessing one 42 // component of a scattered vector or vector pointer. 43 class Scatterer { 44 public: 45 Scatterer() {} 46 47 // Scatter V into Size components. If new instructions are needed, 48 // insert them before BBI in BB. If Cache is nonnull, use it to cache 49 // the results. 50 Scatterer(BasicBlock *bb, BasicBlock::iterator bbi, Value *v, 51 ValueVector *cachePtr = nullptr); 52 53 // Return component I, creating a new Value for it if necessary. 54 Value *operator[](unsigned I); 55 56 // Return the number of components. 57 unsigned size() const { return Size; } 58 59 private: 60 BasicBlock *BB; 61 BasicBlock::iterator BBI; 62 Value *V; 63 ValueVector *CachePtr; 64 PointerType *PtrTy; 65 ValueVector Tmp; 66 unsigned Size; 67 }; 68 69 // FCmpSpliiter(FCI)(Builder, X, Y, Name) uses Builder to create an FCmp 70 // called Name that compares X and Y in the same way as FCI. 71 struct FCmpSplitter { 72 FCmpSplitter(FCmpInst &fci) : FCI(fci) {} 73 Value *operator()(IRBuilder<> &Builder, Value *Op0, Value *Op1, 74 const Twine &Name) const { 75 return Builder.CreateFCmp(FCI.getPredicate(), Op0, Op1, Name); 76 } 77 FCmpInst &FCI; 78 }; 79 80 // ICmpSpliiter(ICI)(Builder, X, Y, Name) uses Builder to create an ICmp 81 // called Name that compares X and Y in the same way as ICI. 82 struct ICmpSplitter { 83 ICmpSplitter(ICmpInst &ici) : ICI(ici) {} 84 Value *operator()(IRBuilder<> &Builder, Value *Op0, Value *Op1, 85 const Twine &Name) const { 86 return Builder.CreateICmp(ICI.getPredicate(), Op0, Op1, Name); 87 } 88 ICmpInst &ICI; 89 }; 90 91 // BinarySpliiter(BO)(Builder, X, Y, Name) uses Builder to create 92 // a binary operator like BO called Name with operands X and Y. 93 struct BinarySplitter { 94 BinarySplitter(BinaryOperator &bo) : BO(bo) {} 95 Value *operator()(IRBuilder<> &Builder, Value *Op0, Value *Op1, 96 const Twine &Name) const { 97 return Builder.CreateBinOp(BO.getOpcode(), Op0, Op1, Name); 98 } 99 BinaryOperator &BO; 100 }; 101 102 // Information about a load or store that we're scalarizing. 103 struct VectorLayout { 104 VectorLayout() : VecTy(nullptr), ElemTy(nullptr), VecAlign(0), ElemSize(0) {} 105 106 // Return the alignment of element I. 107 uint64_t getElemAlign(unsigned I) { 108 return MinAlign(VecAlign, I * ElemSize); 109 } 110 111 // The type of the vector. 112 VectorType *VecTy; 113 114 // The type of each element. 115 Type *ElemTy; 116 117 // The alignment of the vector. 118 uint64_t VecAlign; 119 120 // The size of each element. 121 uint64_t ElemSize; 122 }; 123 124 class Scalarizer : public FunctionPass, 125 public InstVisitor<Scalarizer, bool> { 126 public: 127 static char ID; 128 129 Scalarizer() : 130 FunctionPass(ID) { 131 initializeScalarizerPass(*PassRegistry::getPassRegistry()); 132 } 133 134 bool doInitialization(Module &M) override; 135 bool runOnFunction(Function &F) override; 136 137 // InstVisitor methods. They return true if the instruction was scalarized, 138 // false if nothing changed. 139 bool visitInstruction(Instruction &) { return false; } 140 bool visitSelectInst(SelectInst &SI); 141 bool visitICmpInst(ICmpInst &); 142 bool visitFCmpInst(FCmpInst &); 143 bool visitBinaryOperator(BinaryOperator &); 144 bool visitGetElementPtrInst(GetElementPtrInst &); 145 bool visitCastInst(CastInst &); 146 bool visitBitCastInst(BitCastInst &); 147 bool visitShuffleVectorInst(ShuffleVectorInst &); 148 bool visitPHINode(PHINode &); 149 bool visitLoadInst(LoadInst &); 150 bool visitStoreInst(StoreInst &); 151 152 static void registerOptions() { 153 // This is disabled by default because having separate loads and stores 154 // makes it more likely that the -combiner-alias-analysis limits will be 155 // reached. 156 OptionRegistry::registerOption<bool, Scalarizer, 157 &Scalarizer::ScalarizeLoadStore>( 158 "scalarize-load-store", 159 "Allow the scalarizer pass to scalarize loads and store", false); 160 } 161 162 private: 163 Scatterer scatter(Instruction *, Value *); 164 void gather(Instruction *, const ValueVector &); 165 bool canTransferMetadata(unsigned Kind); 166 void transferMetadata(Instruction *, const ValueVector &); 167 bool getVectorLayout(Type *, unsigned, VectorLayout &, const DataLayout &); 168 bool finish(); 169 170 template<typename T> bool splitBinary(Instruction &, const T &); 171 172 ScatterMap Scattered; 173 GatherList Gathered; 174 unsigned ParallelLoopAccessMDKind; 175 bool ScalarizeLoadStore; 176 }; 177 178 char Scalarizer::ID = 0; 179 } // end anonymous namespace 180 181 INITIALIZE_PASS_WITH_OPTIONS(Scalarizer, "scalarizer", 182 "Scalarize vector operations", false, false) 183 184 Scatterer::Scatterer(BasicBlock *bb, BasicBlock::iterator bbi, Value *v, 185 ValueVector *cachePtr) 186 : BB(bb), BBI(bbi), V(v), CachePtr(cachePtr) { 187 Type *Ty = V->getType(); 188 PtrTy = dyn_cast<PointerType>(Ty); 189 if (PtrTy) 190 Ty = PtrTy->getElementType(); 191 Size = Ty->getVectorNumElements(); 192 if (!CachePtr) 193 Tmp.resize(Size, nullptr); 194 else if (CachePtr->empty()) 195 CachePtr->resize(Size, nullptr); 196 else 197 assert(Size == CachePtr->size() && "Inconsistent vector sizes"); 198 } 199 200 // Return component I, creating a new Value for it if necessary. 201 Value *Scatterer::operator[](unsigned I) { 202 ValueVector &CV = (CachePtr ? *CachePtr : Tmp); 203 // Try to reuse a previous value. 204 if (CV[I]) 205 return CV[I]; 206 IRBuilder<> Builder(BB, BBI); 207 if (PtrTy) { 208 if (!CV[0]) { 209 Type *Ty = 210 PointerType::get(PtrTy->getElementType()->getVectorElementType(), 211 PtrTy->getAddressSpace()); 212 CV[0] = Builder.CreateBitCast(V, Ty, V->getName() + ".i0"); 213 } 214 if (I != 0) 215 CV[I] = Builder.CreateConstGEP1_32(nullptr, CV[0], I, 216 V->getName() + ".i" + Twine(I)); 217 } else { 218 // Search through a chain of InsertElementInsts looking for element I. 219 // Record other elements in the cache. The new V is still suitable 220 // for all uncached indices. 221 for (;;) { 222 InsertElementInst *Insert = dyn_cast<InsertElementInst>(V); 223 if (!Insert) 224 break; 225 ConstantInt *Idx = dyn_cast<ConstantInt>(Insert->getOperand(2)); 226 if (!Idx) 227 break; 228 unsigned J = Idx->getZExtValue(); 229 V = Insert->getOperand(0); 230 if (I == J) { 231 CV[J] = Insert->getOperand(1); 232 return CV[J]; 233 } else if (!CV[J]) { 234 // Only cache the first entry we find for each index we're not actively 235 // searching for. This prevents us from going too far up the chain and 236 // caching incorrect entries. 237 CV[J] = Insert->getOperand(1); 238 } 239 } 240 CV[I] = Builder.CreateExtractElement(V, Builder.getInt32(I), 241 V->getName() + ".i" + Twine(I)); 242 } 243 return CV[I]; 244 } 245 246 bool Scalarizer::doInitialization(Module &M) { 247 ParallelLoopAccessMDKind = 248 M.getContext().getMDKindID("llvm.mem.parallel_loop_access"); 249 ScalarizeLoadStore = 250 M.getContext().getOption<bool, Scalarizer, &Scalarizer::ScalarizeLoadStore>(); 251 return false; 252 } 253 254 bool Scalarizer::runOnFunction(Function &F) { 255 if (skipFunction(F)) 256 return false; 257 assert(Gathered.empty() && Scattered.empty()); 258 for (BasicBlock &BB : F) { 259 for (BasicBlock::iterator II = BB.begin(), IE = BB.end(); II != IE;) { 260 Instruction *I = &*II; 261 bool Done = visit(I); 262 ++II; 263 if (Done && I->getType()->isVoidTy()) 264 I->eraseFromParent(); 265 } 266 } 267 return finish(); 268 } 269 270 // Return a scattered form of V that can be accessed by Point. V must be a 271 // vector or a pointer to a vector. 272 Scatterer Scalarizer::scatter(Instruction *Point, Value *V) { 273 if (Argument *VArg = dyn_cast<Argument>(V)) { 274 // Put the scattered form of arguments in the entry block, 275 // so that it can be used everywhere. 276 Function *F = VArg->getParent(); 277 BasicBlock *BB = &F->getEntryBlock(); 278 return Scatterer(BB, BB->begin(), V, &Scattered[V]); 279 } 280 if (Instruction *VOp = dyn_cast<Instruction>(V)) { 281 // Put the scattered form of an instruction directly after the 282 // instruction. 283 BasicBlock *BB = VOp->getParent(); 284 return Scatterer(BB, std::next(BasicBlock::iterator(VOp)), 285 V, &Scattered[V]); 286 } 287 // In the fallback case, just put the scattered before Point and 288 // keep the result local to Point. 289 return Scatterer(Point->getParent(), Point->getIterator(), V); 290 } 291 292 // Replace Op with the gathered form of the components in CV. Defer the 293 // deletion of Op and creation of the gathered form to the end of the pass, 294 // so that we can avoid creating the gathered form if all uses of Op are 295 // replaced with uses of CV. 296 void Scalarizer::gather(Instruction *Op, const ValueVector &CV) { 297 // Since we're not deleting Op yet, stub out its operands, so that it 298 // doesn't make anything live unnecessarily. 299 for (unsigned I = 0, E = Op->getNumOperands(); I != E; ++I) 300 Op->setOperand(I, UndefValue::get(Op->getOperand(I)->getType())); 301 302 transferMetadata(Op, CV); 303 304 // If we already have a scattered form of Op (created from ExtractElements 305 // of Op itself), replace them with the new form. 306 ValueVector &SV = Scattered[Op]; 307 if (!SV.empty()) { 308 for (unsigned I = 0, E = SV.size(); I != E; ++I) { 309 Value *V = SV[I]; 310 if (V == nullptr) 311 continue; 312 313 Instruction *Old = cast<Instruction>(V); 314 CV[I]->takeName(Old); 315 Old->replaceAllUsesWith(CV[I]); 316 Old->eraseFromParent(); 317 } 318 } 319 SV = CV; 320 Gathered.push_back(GatherList::value_type(Op, &SV)); 321 } 322 323 // Return true if it is safe to transfer the given metadata tag from 324 // vector to scalar instructions. 325 bool Scalarizer::canTransferMetadata(unsigned Tag) { 326 return (Tag == LLVMContext::MD_tbaa 327 || Tag == LLVMContext::MD_fpmath 328 || Tag == LLVMContext::MD_tbaa_struct 329 || Tag == LLVMContext::MD_invariant_load 330 || Tag == LLVMContext::MD_alias_scope 331 || Tag == LLVMContext::MD_noalias 332 || Tag == ParallelLoopAccessMDKind); 333 } 334 335 // Transfer metadata from Op to the instructions in CV if it is known 336 // to be safe to do so. 337 void Scalarizer::transferMetadata(Instruction *Op, const ValueVector &CV) { 338 SmallVector<std::pair<unsigned, MDNode *>, 4> MDs; 339 Op->getAllMetadataOtherThanDebugLoc(MDs); 340 for (unsigned I = 0, E = CV.size(); I != E; ++I) { 341 if (Instruction *New = dyn_cast<Instruction>(CV[I])) { 342 for (const auto &MD : MDs) 343 if (canTransferMetadata(MD.first)) 344 New->setMetadata(MD.first, MD.second); 345 if (Op->getDebugLoc() && !New->getDebugLoc()) 346 New->setDebugLoc(Op->getDebugLoc()); 347 } 348 } 349 } 350 351 // Try to fill in Layout from Ty, returning true on success. Alignment is 352 // the alignment of the vector, or 0 if the ABI default should be used. 353 bool Scalarizer::getVectorLayout(Type *Ty, unsigned Alignment, 354 VectorLayout &Layout, const DataLayout &DL) { 355 // Make sure we're dealing with a vector. 356 Layout.VecTy = dyn_cast<VectorType>(Ty); 357 if (!Layout.VecTy) 358 return false; 359 360 // Check that we're dealing with full-byte elements. 361 Layout.ElemTy = Layout.VecTy->getElementType(); 362 if (DL.getTypeSizeInBits(Layout.ElemTy) != 363 DL.getTypeStoreSizeInBits(Layout.ElemTy)) 364 return false; 365 366 if (Alignment) 367 Layout.VecAlign = Alignment; 368 else 369 Layout.VecAlign = DL.getABITypeAlignment(Layout.VecTy); 370 Layout.ElemSize = DL.getTypeStoreSize(Layout.ElemTy); 371 return true; 372 } 373 374 // Scalarize two-operand instruction I, using Split(Builder, X, Y, Name) 375 // to create an instruction like I with operands X and Y and name Name. 376 template<typename Splitter> 377 bool Scalarizer::splitBinary(Instruction &I, const Splitter &Split) { 378 VectorType *VT = dyn_cast<VectorType>(I.getType()); 379 if (!VT) 380 return false; 381 382 unsigned NumElems = VT->getNumElements(); 383 IRBuilder<> Builder(&I); 384 Scatterer Op0 = scatter(&I, I.getOperand(0)); 385 Scatterer Op1 = scatter(&I, I.getOperand(1)); 386 assert(Op0.size() == NumElems && "Mismatched binary operation"); 387 assert(Op1.size() == NumElems && "Mismatched binary operation"); 388 ValueVector Res; 389 Res.resize(NumElems); 390 for (unsigned Elem = 0; Elem < NumElems; ++Elem) 391 Res[Elem] = Split(Builder, Op0[Elem], Op1[Elem], 392 I.getName() + ".i" + Twine(Elem)); 393 gather(&I, Res); 394 return true; 395 } 396 397 bool Scalarizer::visitSelectInst(SelectInst &SI) { 398 VectorType *VT = dyn_cast<VectorType>(SI.getType()); 399 if (!VT) 400 return false; 401 402 unsigned NumElems = VT->getNumElements(); 403 IRBuilder<> Builder(&SI); 404 Scatterer Op1 = scatter(&SI, SI.getOperand(1)); 405 Scatterer Op2 = scatter(&SI, SI.getOperand(2)); 406 assert(Op1.size() == NumElems && "Mismatched select"); 407 assert(Op2.size() == NumElems && "Mismatched select"); 408 ValueVector Res; 409 Res.resize(NumElems); 410 411 if (SI.getOperand(0)->getType()->isVectorTy()) { 412 Scatterer Op0 = scatter(&SI, SI.getOperand(0)); 413 assert(Op0.size() == NumElems && "Mismatched select"); 414 for (unsigned I = 0; I < NumElems; ++I) 415 Res[I] = Builder.CreateSelect(Op0[I], Op1[I], Op2[I], 416 SI.getName() + ".i" + Twine(I)); 417 } else { 418 Value *Op0 = SI.getOperand(0); 419 for (unsigned I = 0; I < NumElems; ++I) 420 Res[I] = Builder.CreateSelect(Op0, Op1[I], Op2[I], 421 SI.getName() + ".i" + Twine(I)); 422 } 423 gather(&SI, Res); 424 return true; 425 } 426 427 bool Scalarizer::visitICmpInst(ICmpInst &ICI) { 428 return splitBinary(ICI, ICmpSplitter(ICI)); 429 } 430 431 bool Scalarizer::visitFCmpInst(FCmpInst &FCI) { 432 return splitBinary(FCI, FCmpSplitter(FCI)); 433 } 434 435 bool Scalarizer::visitBinaryOperator(BinaryOperator &BO) { 436 return splitBinary(BO, BinarySplitter(BO)); 437 } 438 439 bool Scalarizer::visitGetElementPtrInst(GetElementPtrInst &GEPI) { 440 VectorType *VT = dyn_cast<VectorType>(GEPI.getType()); 441 if (!VT) 442 return false; 443 444 IRBuilder<> Builder(&GEPI); 445 unsigned NumElems = VT->getNumElements(); 446 unsigned NumIndices = GEPI.getNumIndices(); 447 448 Scatterer Base = scatter(&GEPI, GEPI.getOperand(0)); 449 450 SmallVector<Scatterer, 8> Ops; 451 Ops.resize(NumIndices); 452 for (unsigned I = 0; I < NumIndices; ++I) 453 Ops[I] = scatter(&GEPI, GEPI.getOperand(I + 1)); 454 455 ValueVector Res; 456 Res.resize(NumElems); 457 for (unsigned I = 0; I < NumElems; ++I) { 458 SmallVector<Value *, 8> Indices; 459 Indices.resize(NumIndices); 460 for (unsigned J = 0; J < NumIndices; ++J) 461 Indices[J] = Ops[J][I]; 462 Res[I] = Builder.CreateGEP(GEPI.getSourceElementType(), Base[I], Indices, 463 GEPI.getName() + ".i" + Twine(I)); 464 if (GEPI.isInBounds()) 465 if (GetElementPtrInst *NewGEPI = dyn_cast<GetElementPtrInst>(Res[I])) 466 NewGEPI->setIsInBounds(); 467 } 468 gather(&GEPI, Res); 469 return true; 470 } 471 472 bool Scalarizer::visitCastInst(CastInst &CI) { 473 VectorType *VT = dyn_cast<VectorType>(CI.getDestTy()); 474 if (!VT) 475 return false; 476 477 unsigned NumElems = VT->getNumElements(); 478 IRBuilder<> Builder(&CI); 479 Scatterer Op0 = scatter(&CI, CI.getOperand(0)); 480 assert(Op0.size() == NumElems && "Mismatched cast"); 481 ValueVector Res; 482 Res.resize(NumElems); 483 for (unsigned I = 0; I < NumElems; ++I) 484 Res[I] = Builder.CreateCast(CI.getOpcode(), Op0[I], VT->getElementType(), 485 CI.getName() + ".i" + Twine(I)); 486 gather(&CI, Res); 487 return true; 488 } 489 490 bool Scalarizer::visitBitCastInst(BitCastInst &BCI) { 491 VectorType *DstVT = dyn_cast<VectorType>(BCI.getDestTy()); 492 VectorType *SrcVT = dyn_cast<VectorType>(BCI.getSrcTy()); 493 if (!DstVT || !SrcVT) 494 return false; 495 496 unsigned DstNumElems = DstVT->getNumElements(); 497 unsigned SrcNumElems = SrcVT->getNumElements(); 498 IRBuilder<> Builder(&BCI); 499 Scatterer Op0 = scatter(&BCI, BCI.getOperand(0)); 500 ValueVector Res; 501 Res.resize(DstNumElems); 502 503 if (DstNumElems == SrcNumElems) { 504 for (unsigned I = 0; I < DstNumElems; ++I) 505 Res[I] = Builder.CreateBitCast(Op0[I], DstVT->getElementType(), 506 BCI.getName() + ".i" + Twine(I)); 507 } else if (DstNumElems > SrcNumElems) { 508 // <M x t1> -> <N*M x t2>. Convert each t1 to <N x t2> and copy the 509 // individual elements to the destination. 510 unsigned FanOut = DstNumElems / SrcNumElems; 511 Type *MidTy = VectorType::get(DstVT->getElementType(), FanOut); 512 unsigned ResI = 0; 513 for (unsigned Op0I = 0; Op0I < SrcNumElems; ++Op0I) { 514 Value *V = Op0[Op0I]; 515 Instruction *VI; 516 // Look through any existing bitcasts before converting to <N x t2>. 517 // In the best case, the resulting conversion might be a no-op. 518 while ((VI = dyn_cast<Instruction>(V)) && 519 VI->getOpcode() == Instruction::BitCast) 520 V = VI->getOperand(0); 521 V = Builder.CreateBitCast(V, MidTy, V->getName() + ".cast"); 522 Scatterer Mid = scatter(&BCI, V); 523 for (unsigned MidI = 0; MidI < FanOut; ++MidI) 524 Res[ResI++] = Mid[MidI]; 525 } 526 } else { 527 // <N*M x t1> -> <M x t2>. Convert each group of <N x t1> into a t2. 528 unsigned FanIn = SrcNumElems / DstNumElems; 529 Type *MidTy = VectorType::get(SrcVT->getElementType(), FanIn); 530 unsigned Op0I = 0; 531 for (unsigned ResI = 0; ResI < DstNumElems; ++ResI) { 532 Value *V = UndefValue::get(MidTy); 533 for (unsigned MidI = 0; MidI < FanIn; ++MidI) 534 V = Builder.CreateInsertElement(V, Op0[Op0I++], Builder.getInt32(MidI), 535 BCI.getName() + ".i" + Twine(ResI) 536 + ".upto" + Twine(MidI)); 537 Res[ResI] = Builder.CreateBitCast(V, DstVT->getElementType(), 538 BCI.getName() + ".i" + Twine(ResI)); 539 } 540 } 541 gather(&BCI, Res); 542 return true; 543 } 544 545 bool Scalarizer::visitShuffleVectorInst(ShuffleVectorInst &SVI) { 546 VectorType *VT = dyn_cast<VectorType>(SVI.getType()); 547 if (!VT) 548 return false; 549 550 unsigned NumElems = VT->getNumElements(); 551 Scatterer Op0 = scatter(&SVI, SVI.getOperand(0)); 552 Scatterer Op1 = scatter(&SVI, SVI.getOperand(1)); 553 ValueVector Res; 554 Res.resize(NumElems); 555 556 for (unsigned I = 0; I < NumElems; ++I) { 557 int Selector = SVI.getMaskValue(I); 558 if (Selector < 0) 559 Res[I] = UndefValue::get(VT->getElementType()); 560 else if (unsigned(Selector) < Op0.size()) 561 Res[I] = Op0[Selector]; 562 else 563 Res[I] = Op1[Selector - Op0.size()]; 564 } 565 gather(&SVI, Res); 566 return true; 567 } 568 569 bool Scalarizer::visitPHINode(PHINode &PHI) { 570 VectorType *VT = dyn_cast<VectorType>(PHI.getType()); 571 if (!VT) 572 return false; 573 574 unsigned NumElems = VT->getNumElements(); 575 IRBuilder<> Builder(&PHI); 576 ValueVector Res; 577 Res.resize(NumElems); 578 579 unsigned NumOps = PHI.getNumOperands(); 580 for (unsigned I = 0; I < NumElems; ++I) 581 Res[I] = Builder.CreatePHI(VT->getElementType(), NumOps, 582 PHI.getName() + ".i" + Twine(I)); 583 584 for (unsigned I = 0; I < NumOps; ++I) { 585 Scatterer Op = scatter(&PHI, PHI.getIncomingValue(I)); 586 BasicBlock *IncomingBlock = PHI.getIncomingBlock(I); 587 for (unsigned J = 0; J < NumElems; ++J) 588 cast<PHINode>(Res[J])->addIncoming(Op[J], IncomingBlock); 589 } 590 gather(&PHI, Res); 591 return true; 592 } 593 594 bool Scalarizer::visitLoadInst(LoadInst &LI) { 595 if (!ScalarizeLoadStore) 596 return false; 597 if (!LI.isSimple()) 598 return false; 599 600 VectorLayout Layout; 601 if (!getVectorLayout(LI.getType(), LI.getAlignment(), Layout, 602 LI.getModule()->getDataLayout())) 603 return false; 604 605 unsigned NumElems = Layout.VecTy->getNumElements(); 606 IRBuilder<> Builder(&LI); 607 Scatterer Ptr = scatter(&LI, LI.getPointerOperand()); 608 ValueVector Res; 609 Res.resize(NumElems); 610 611 for (unsigned I = 0; I < NumElems; ++I) 612 Res[I] = Builder.CreateAlignedLoad(Ptr[I], Layout.getElemAlign(I), 613 LI.getName() + ".i" + Twine(I)); 614 gather(&LI, Res); 615 return true; 616 } 617 618 bool Scalarizer::visitStoreInst(StoreInst &SI) { 619 if (!ScalarizeLoadStore) 620 return false; 621 if (!SI.isSimple()) 622 return false; 623 624 VectorLayout Layout; 625 Value *FullValue = SI.getValueOperand(); 626 if (!getVectorLayout(FullValue->getType(), SI.getAlignment(), Layout, 627 SI.getModule()->getDataLayout())) 628 return false; 629 630 unsigned NumElems = Layout.VecTy->getNumElements(); 631 IRBuilder<> Builder(&SI); 632 Scatterer Ptr = scatter(&SI, SI.getPointerOperand()); 633 Scatterer Val = scatter(&SI, FullValue); 634 635 ValueVector Stores; 636 Stores.resize(NumElems); 637 for (unsigned I = 0; I < NumElems; ++I) { 638 unsigned Align = Layout.getElemAlign(I); 639 Stores[I] = Builder.CreateAlignedStore(Val[I], Ptr[I], Align); 640 } 641 transferMetadata(&SI, Stores); 642 return true; 643 } 644 645 // Delete the instructions that we scalarized. If a full vector result 646 // is still needed, recreate it using InsertElements. 647 bool Scalarizer::finish() { 648 // The presence of data in Gathered or Scattered indicates changes 649 // made to the Function. 650 if (Gathered.empty() && Scattered.empty()) 651 return false; 652 for (const auto &GMI : Gathered) { 653 Instruction *Op = GMI.first; 654 ValueVector &CV = *GMI.second; 655 if (!Op->use_empty()) { 656 // The value is still needed, so recreate it using a series of 657 // InsertElements. 658 Type *Ty = Op->getType(); 659 Value *Res = UndefValue::get(Ty); 660 BasicBlock *BB = Op->getParent(); 661 unsigned Count = Ty->getVectorNumElements(); 662 IRBuilder<> Builder(Op); 663 if (isa<PHINode>(Op)) 664 Builder.SetInsertPoint(BB, BB->getFirstInsertionPt()); 665 for (unsigned I = 0; I < Count; ++I) 666 Res = Builder.CreateInsertElement(Res, CV[I], Builder.getInt32(I), 667 Op->getName() + ".upto" + Twine(I)); 668 Res->takeName(Op); 669 Op->replaceAllUsesWith(Res); 670 } 671 Op->eraseFromParent(); 672 } 673 Gathered.clear(); 674 Scattered.clear(); 675 return true; 676 } 677 678 FunctionPass *llvm::createScalarizerPass() { 679 return new Scalarizer(); 680 } 681