ScalarReplAggregates.cpp revision 843f0767acd05baed952d39e77ea89b438430a4f
1//===- ScalarReplAggregates.cpp - Scalar Replacement of Aggregates --------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file was developed by the LLVM research group and is distributed under 6// the University of Illinois Open Source License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This transformation implements the well known scalar replacement of 11// aggregates transformation. This xform breaks up alloca instructions of 12// aggregate type (structure or array) into individual alloca instructions for 13// each member (if possible). Then, if possible, it transforms the individual 14// alloca instructions into nice clean scalar SSA form. 15// 16// This combines a simple SRoA algorithm with the Mem2Reg algorithm because 17// often interact, especially for C++ programs. As such, iterating between 18// SRoA, then Mem2Reg until we run out of things to promote works well. 19// 20//===----------------------------------------------------------------------===// 21 22#define DEBUG_TYPE "scalarrepl" 23#include "llvm/Transforms/Scalar.h" 24#include "llvm/Constants.h" 25#include "llvm/DerivedTypes.h" 26#include "llvm/Function.h" 27#include "llvm/Instructions.h" 28#include "llvm/IntrinsicInst.h" 29#include "llvm/Pass.h" 30#include "llvm/Analysis/Dominators.h" 31#include "llvm/Target/TargetData.h" 32#include "llvm/Transforms/Utils/PromoteMemToReg.h" 33#include "llvm/Support/Debug.h" 34#include "llvm/Support/GetElementPtrTypeIterator.h" 35#include "llvm/Support/MathExtras.h" 36#include "llvm/Support/Compiler.h" 37#include "llvm/ADT/SmallVector.h" 38#include "llvm/ADT/Statistic.h" 39#include "llvm/ADT/StringExtras.h" 40using namespace llvm; 41 42STATISTIC(NumReplaced, "Number of allocas broken up"); 43STATISTIC(NumPromoted, "Number of allocas promoted"); 44STATISTIC(NumConverted, "Number of aggregates converted to scalar"); 45 46namespace { 47 struct VISIBILITY_HIDDEN SROA : public FunctionPass { 48 bool runOnFunction(Function &F); 49 50 bool performScalarRepl(Function &F); 51 bool performPromotion(Function &F); 52 53 // getAnalysisUsage - This pass does not require any passes, but we know it 54 // will not alter the CFG, so say so. 55 virtual void getAnalysisUsage(AnalysisUsage &AU) const { 56 AU.addRequired<DominatorTree>(); 57 AU.addRequired<DominanceFrontier>(); 58 AU.addRequired<TargetData>(); 59 AU.setPreservesCFG(); 60 } 61 62 private: 63 int isSafeElementUse(Value *Ptr, bool isFirstElt, AllocationInst *AI); 64 int isSafeUseOfAllocation(Instruction *User, AllocationInst *AI); 65 bool isSafeMemIntrinsicOnAllocation(MemIntrinsic *MI, AllocationInst *AI); 66 bool isSafeUseOfBitCastedAllocation(BitCastInst *User, AllocationInst *AI); 67 int isSafeAllocaToScalarRepl(AllocationInst *AI); 68 void CanonicalizeAllocaUsers(AllocationInst *AI); 69 AllocaInst *AddNewAlloca(Function &F, const Type *Ty, AllocationInst *Base); 70 71 void RewriteBitCastUserOfAlloca(Instruction *BCInst, AllocationInst *AI, 72 SmallVector<AllocaInst*, 32> &NewElts); 73 74 const Type *CanConvertToScalar(Value *V, bool &IsNotTrivial); 75 void ConvertToScalar(AllocationInst *AI, const Type *Ty); 76 void ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, unsigned Offset); 77 }; 78 79 RegisterPass<SROA> X("scalarrepl", "Scalar Replacement of Aggregates"); 80} 81 82// Public interface to the ScalarReplAggregates pass 83FunctionPass *llvm::createScalarReplAggregatesPass() { return new SROA(); } 84 85 86bool SROA::runOnFunction(Function &F) { 87 bool Changed = performPromotion(F); 88 while (1) { 89 bool LocalChange = performScalarRepl(F); 90 if (!LocalChange) break; // No need to repromote if no scalarrepl 91 Changed = true; 92 LocalChange = performPromotion(F); 93 if (!LocalChange) break; // No need to re-scalarrepl if no promotion 94 } 95 96 return Changed; 97} 98 99 100bool SROA::performPromotion(Function &F) { 101 std::vector<AllocaInst*> Allocas; 102 const TargetData &TD = getAnalysis<TargetData>(); 103 DominatorTree &DT = getAnalysis<DominatorTree>(); 104 DominanceFrontier &DF = getAnalysis<DominanceFrontier>(); 105 106 BasicBlock &BB = F.getEntryBlock(); // Get the entry node for the function 107 108 bool Changed = false; 109 110 while (1) { 111 Allocas.clear(); 112 113 // Find allocas that are safe to promote, by looking at all instructions in 114 // the entry node 115 for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I) 116 if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) // Is it an alloca? 117 if (isAllocaPromotable(AI, TD)) 118 Allocas.push_back(AI); 119 120 if (Allocas.empty()) break; 121 122 PromoteMemToReg(Allocas, DT, DF, TD); 123 NumPromoted += Allocas.size(); 124 Changed = true; 125 } 126 127 return Changed; 128} 129 130// performScalarRepl - This algorithm is a simple worklist driven algorithm, 131// which runs on all of the malloc/alloca instructions in the function, removing 132// them if they are only used by getelementptr instructions. 133// 134bool SROA::performScalarRepl(Function &F) { 135 std::vector<AllocationInst*> WorkList; 136 137 // Scan the entry basic block, adding any alloca's and mallocs to the worklist 138 BasicBlock &BB = F.getEntryBlock(); 139 for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I) 140 if (AllocationInst *A = dyn_cast<AllocationInst>(I)) 141 WorkList.push_back(A); 142 143 // Process the worklist 144 bool Changed = false; 145 while (!WorkList.empty()) { 146 AllocationInst *AI = WorkList.back(); 147 WorkList.pop_back(); 148 149 // Handle dead allocas trivially. These can be formed by SROA'ing arrays 150 // with unused elements. 151 if (AI->use_empty()) { 152 AI->eraseFromParent(); 153 continue; 154 } 155 156 // If we can turn this aggregate value (potentially with casts) into a 157 // simple scalar value that can be mem2reg'd into a register value. 158 bool IsNotTrivial = false; 159 if (const Type *ActualType = CanConvertToScalar(AI, IsNotTrivial)) 160 if (IsNotTrivial && ActualType != Type::VoidTy) { 161 ConvertToScalar(AI, ActualType); 162 Changed = true; 163 continue; 164 } 165 166 // We cannot transform the allocation instruction if it is an array 167 // allocation (allocations OF arrays are ok though), and an allocation of a 168 // scalar value cannot be decomposed at all. 169 // 170 if (AI->isArrayAllocation() || 171 (!isa<StructType>(AI->getAllocatedType()) && 172 !isa<ArrayType>(AI->getAllocatedType()))) continue; 173 174 // Check that all of the users of the allocation are capable of being 175 // transformed. 176 switch (isSafeAllocaToScalarRepl(AI)) { 177 default: assert(0 && "Unexpected value!"); 178 case 0: // Not safe to scalar replace. 179 continue; 180 case 1: // Safe, but requires cleanup/canonicalizations first 181 CanonicalizeAllocaUsers(AI); 182 case 3: // Safe to scalar replace. 183 break; 184 } 185 186 DOUT << "Found inst to xform: " << *AI; 187 Changed = true; 188 189 SmallVector<AllocaInst*, 32> ElementAllocas; 190 if (const StructType *ST = dyn_cast<StructType>(AI->getAllocatedType())) { 191 ElementAllocas.reserve(ST->getNumContainedTypes()); 192 for (unsigned i = 0, e = ST->getNumContainedTypes(); i != e; ++i) { 193 AllocaInst *NA = new AllocaInst(ST->getContainedType(i), 0, 194 AI->getAlignment(), 195 AI->getName() + "." + utostr(i), AI); 196 ElementAllocas.push_back(NA); 197 WorkList.push_back(NA); // Add to worklist for recursive processing 198 } 199 } else { 200 const ArrayType *AT = cast<ArrayType>(AI->getAllocatedType()); 201 ElementAllocas.reserve(AT->getNumElements()); 202 const Type *ElTy = AT->getElementType(); 203 for (unsigned i = 0, e = AT->getNumElements(); i != e; ++i) { 204 AllocaInst *NA = new AllocaInst(ElTy, 0, AI->getAlignment(), 205 AI->getName() + "." + utostr(i), AI); 206 ElementAllocas.push_back(NA); 207 WorkList.push_back(NA); // Add to worklist for recursive processing 208 } 209 } 210 211 // Now that we have created the alloca instructions that we want to use, 212 // expand the getelementptr instructions to use them. 213 // 214 while (!AI->use_empty()) { 215 Instruction *User = cast<Instruction>(AI->use_back()); 216 if (BitCastInst *BCInst = dyn_cast<BitCastInst>(User)) { 217 RewriteBitCastUserOfAlloca(BCInst, AI, ElementAllocas); 218 BCInst->eraseFromParent(); 219 continue; 220 } 221 222 GetElementPtrInst *GEPI = cast<GetElementPtrInst>(User); 223 // We now know that the GEP is of the form: GEP <ptr>, 0, <cst> 224 unsigned Idx = 225 (unsigned)cast<ConstantInt>(GEPI->getOperand(2))->getZExtValue(); 226 227 assert(Idx < ElementAllocas.size() && "Index out of range?"); 228 AllocaInst *AllocaToUse = ElementAllocas[Idx]; 229 230 Value *RepValue; 231 if (GEPI->getNumOperands() == 3) { 232 // Do not insert a new getelementptr instruction with zero indices, only 233 // to have it optimized out later. 234 RepValue = AllocaToUse; 235 } else { 236 // We are indexing deeply into the structure, so we still need a 237 // getelement ptr instruction to finish the indexing. This may be 238 // expanded itself once the worklist is rerun. 239 // 240 SmallVector<Value*, 8> NewArgs; 241 NewArgs.push_back(Constant::getNullValue(Type::Int32Ty)); 242 NewArgs.append(GEPI->op_begin()+3, GEPI->op_end()); 243 RepValue = new GetElementPtrInst(AllocaToUse, &NewArgs[0], 244 NewArgs.size(), "", GEPI); 245 RepValue->takeName(GEPI); 246 } 247 248 // If this GEP is to the start of the aggregate, check for memcpys. 249 if (Idx == 0) { 250 bool IsStartOfAggregateGEP = true; 251 for (unsigned i = 3, e = GEPI->getNumOperands(); i != e; ++i) { 252 if (!isa<ConstantInt>(GEPI->getOperand(i))) { 253 IsStartOfAggregateGEP = false; 254 break; 255 } 256 if (!cast<ConstantInt>(GEPI->getOperand(i))->isZero()) { 257 IsStartOfAggregateGEP = false; 258 break; 259 } 260 } 261 262 if (IsStartOfAggregateGEP) 263 RewriteBitCastUserOfAlloca(GEPI, AI, ElementAllocas); 264 } 265 266 267 // Move all of the users over to the new GEP. 268 GEPI->replaceAllUsesWith(RepValue); 269 // Delete the old GEP 270 GEPI->eraseFromParent(); 271 } 272 273 // Finally, delete the Alloca instruction 274 AI->eraseFromParent(); 275 NumReplaced++; 276 } 277 278 return Changed; 279} 280 281 282/// isSafeElementUse - Check to see if this use is an allowed use for a 283/// getelementptr instruction of an array aggregate allocation. isFirstElt 284/// indicates whether Ptr is known to the start of the aggregate. 285/// 286int SROA::isSafeElementUse(Value *Ptr, bool isFirstElt, AllocationInst *AI) { 287 for (Value::use_iterator I = Ptr->use_begin(), E = Ptr->use_end(); 288 I != E; ++I) { 289 Instruction *User = cast<Instruction>(*I); 290 switch (User->getOpcode()) { 291 case Instruction::Load: break; 292 case Instruction::Store: 293 // Store is ok if storing INTO the pointer, not storing the pointer 294 if (User->getOperand(0) == Ptr) return 0; 295 break; 296 case Instruction::GetElementPtr: { 297 GetElementPtrInst *GEP = cast<GetElementPtrInst>(User); 298 bool AreAllZeroIndices = isFirstElt; 299 if (GEP->getNumOperands() > 1) { 300 if (!isa<ConstantInt>(GEP->getOperand(1)) || 301 !cast<ConstantInt>(GEP->getOperand(1))->isZero()) 302 return 0; // Using pointer arithmetic to navigate the array. 303 304 if (AreAllZeroIndices) { 305 for (unsigned i = 2, e = GEP->getNumOperands(); i != e; ++i) { 306 if (!isa<ConstantInt>(GEP->getOperand(i)) || 307 !cast<ConstantInt>(GEP->getOperand(i))->isZero()) { 308 AreAllZeroIndices = false; 309 break; 310 } 311 } 312 } 313 } 314 if (!isSafeElementUse(GEP, AreAllZeroIndices, AI)) return 0; 315 break; 316 } 317 case Instruction::BitCast: 318 if (isFirstElt && 319 isSafeUseOfBitCastedAllocation(cast<BitCastInst>(User), AI)) 320 break; 321 DOUT << " Transformation preventing inst: " << *User; 322 return 0; 323 case Instruction::Call: 324 if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(User)) { 325 if (isFirstElt && isSafeMemIntrinsicOnAllocation(MI, AI)) 326 break; 327 } 328 DOUT << " Transformation preventing inst: " << *User; 329 return 0; 330 default: 331 DOUT << " Transformation preventing inst: " << *User; 332 return 0; 333 } 334 } 335 return 3; // All users look ok :) 336} 337 338/// AllUsersAreLoads - Return true if all users of this value are loads. 339static bool AllUsersAreLoads(Value *Ptr) { 340 for (Value::use_iterator I = Ptr->use_begin(), E = Ptr->use_end(); 341 I != E; ++I) 342 if (cast<Instruction>(*I)->getOpcode() != Instruction::Load) 343 return false; 344 return true; 345} 346 347/// isSafeUseOfAllocation - Check to see if this user is an allowed use for an 348/// aggregate allocation. 349/// 350int SROA::isSafeUseOfAllocation(Instruction *User, AllocationInst *AI) { 351 if (BitCastInst *C = dyn_cast<BitCastInst>(User)) 352 return isSafeUseOfBitCastedAllocation(C, AI) ? 3 : 0; 353 if (!isa<GetElementPtrInst>(User)) return 0; 354 355 GetElementPtrInst *GEPI = cast<GetElementPtrInst>(User); 356 gep_type_iterator I = gep_type_begin(GEPI), E = gep_type_end(GEPI); 357 358 // The GEP is not safe to transform if not of the form "GEP <ptr>, 0, <cst>". 359 if (I == E || 360 I.getOperand() != Constant::getNullValue(I.getOperand()->getType())) 361 return 0; 362 363 ++I; 364 if (I == E) return 0; // ran out of GEP indices?? 365 366 bool IsAllZeroIndices = true; 367 368 // If this is a use of an array allocation, do a bit more checking for sanity. 369 if (const ArrayType *AT = dyn_cast<ArrayType>(*I)) { 370 uint64_t NumElements = AT->getNumElements(); 371 372 if (ConstantInt *Idx = dyn_cast<ConstantInt>(I.getOperand())) { 373 IsAllZeroIndices &= Idx->isZero(); 374 375 // Check to make sure that index falls within the array. If not, 376 // something funny is going on, so we won't do the optimization. 377 // 378 if (Idx->getZExtValue() >= NumElements) 379 return 0; 380 381 // We cannot scalar repl this level of the array unless any array 382 // sub-indices are in-range constants. In particular, consider: 383 // A[0][i]. We cannot know that the user isn't doing invalid things like 384 // allowing i to index an out-of-range subscript that accesses A[1]. 385 // 386 // Scalar replacing *just* the outer index of the array is probably not 387 // going to be a win anyway, so just give up. 388 for (++I; I != E && (isa<ArrayType>(*I) || isa<VectorType>(*I)); ++I) { 389 uint64_t NumElements; 390 if (const ArrayType *SubArrayTy = dyn_cast<ArrayType>(*I)) 391 NumElements = SubArrayTy->getNumElements(); 392 else 393 NumElements = cast<VectorType>(*I)->getNumElements(); 394 395 ConstantInt *IdxVal = dyn_cast<ConstantInt>(I.getOperand()); 396 if (!IdxVal) return 0; 397 if (IdxVal->getZExtValue() >= NumElements) 398 return 0; 399 IsAllZeroIndices &= IdxVal->isZero(); 400 } 401 402 } else { 403 IsAllZeroIndices = 0; 404 405 // If this is an array index and the index is not constant, we cannot 406 // promote... that is unless the array has exactly one or two elements in 407 // it, in which case we CAN promote it, but we have to canonicalize this 408 // out if this is the only problem. 409 if ((NumElements == 1 || NumElements == 2) && 410 AllUsersAreLoads(GEPI)) 411 return 1; // Canonicalization required! 412 return 0; 413 } 414 } 415 416 // If there are any non-simple uses of this getelementptr, make sure to reject 417 // them. 418 return isSafeElementUse(GEPI, IsAllZeroIndices, AI); 419} 420 421/// isSafeMemIntrinsicOnAllocation - Return true if the specified memory 422/// intrinsic can be promoted by SROA. At this point, we know that the operand 423/// of the memintrinsic is a pointer to the beginning of the allocation. 424bool SROA::isSafeMemIntrinsicOnAllocation(MemIntrinsic *MI, AllocationInst *AI){ 425 // If not constant length, give up. 426 ConstantInt *Length = dyn_cast<ConstantInt>(MI->getLength()); 427 if (!Length) return false; 428 429 // If not the whole aggregate, give up. 430 const TargetData &TD = getAnalysis<TargetData>(); 431 if (Length->getZExtValue() != TD.getTypeSize(AI->getType()->getElementType())) 432 return false; 433 434 // We only know about memcpy/memset/memmove. 435 if (!isa<MemCpyInst>(MI) && !isa<MemSetInst>(MI) && !isa<MemMoveInst>(MI)) 436 return false; 437 // Otherwise, we can transform it. 438 return true; 439} 440 441/// isSafeUseOfBitCastedAllocation - Return true if all users of this bitcast 442/// are 443bool SROA::isSafeUseOfBitCastedAllocation(BitCastInst *BC, AllocationInst *AI) { 444 for (Value::use_iterator UI = BC->use_begin(), E = BC->use_end(); 445 UI != E; ++UI) { 446 if (BitCastInst *BCU = dyn_cast<BitCastInst>(UI)) { 447 if (!isSafeUseOfBitCastedAllocation(BCU, AI)) 448 return false; 449 } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(UI)) { 450 if (!isSafeMemIntrinsicOnAllocation(MI, AI)) 451 return false; 452 } else { 453 return false; 454 } 455 } 456 return true; 457} 458 459/// RewriteBitCastUserOfAlloca - BCInst (transitively) bitcasts AI, or indexes 460/// to its first element. Transform users of the cast to use the new values 461/// instead. 462void SROA::RewriteBitCastUserOfAlloca(Instruction *BCInst, AllocationInst *AI, 463 SmallVector<AllocaInst*, 32> &NewElts) { 464 Constant *Zero = Constant::getNullValue(Type::Int32Ty); 465 const TargetData &TD = getAnalysis<TargetData>(); 466 467 Value::use_iterator UI = BCInst->use_begin(), UE = BCInst->use_end(); 468 while (UI != UE) { 469 if (BitCastInst *BCU = dyn_cast<BitCastInst>(*UI)) { 470 RewriteBitCastUserOfAlloca(BCU, AI, NewElts); 471 ++UI; 472 BCU->eraseFromParent(); 473 continue; 474 } 475 476 // Otherwise, must be memcpy/memmove/memset of the entire aggregate. Split 477 // into one per element. 478 MemIntrinsic *MI = dyn_cast<MemIntrinsic>(*UI); 479 480 // If it's not a mem intrinsic, it must be some other user of a gep of the 481 // first pointer. Just leave these alone. 482 if (!MI) { 483 ++UI; 484 continue; 485 } 486 487 // If this is a memcpy/memmove, construct the other pointer as the 488 // appropriate type. 489 Value *OtherPtr = 0; 490 if (MemCpyInst *MCI = dyn_cast<MemCpyInst>(MI)) { 491 if (BCInst == MCI->getRawDest()) 492 OtherPtr = MCI->getRawSource(); 493 else { 494 assert(BCInst == MCI->getRawSource()); 495 OtherPtr = MCI->getRawDest(); 496 } 497 } else if (MemMoveInst *MMI = dyn_cast<MemMoveInst>(MI)) { 498 if (BCInst == MMI->getRawDest()) 499 OtherPtr = MMI->getRawSource(); 500 else { 501 assert(BCInst == MMI->getRawSource()); 502 OtherPtr = MMI->getRawDest(); 503 } 504 } 505 506 // If there is an other pointer, we want to convert it to the same pointer 507 // type as AI has, so we can GEP through it. 508 if (OtherPtr) { 509 // It is likely that OtherPtr is a bitcast, if so, remove it. 510 if (BitCastInst *BC = dyn_cast<BitCastInst>(OtherPtr)) 511 OtherPtr = BC->getOperand(0); 512 if (ConstantExpr *BCE = dyn_cast<ConstantExpr>(OtherPtr)) 513 if (BCE->getOpcode() == Instruction::BitCast) 514 OtherPtr = BCE->getOperand(0); 515 516 // If the pointer is not the right type, insert a bitcast to the right 517 // type. 518 if (OtherPtr->getType() != AI->getType()) 519 OtherPtr = new BitCastInst(OtherPtr, AI->getType(), OtherPtr->getName(), 520 MI); 521 } 522 523 // Process each element of the aggregate. 524 Value *TheFn = MI->getOperand(0); 525 const Type *BytePtrTy = MI->getRawDest()->getType(); 526 bool SROADest = MI->getRawDest() == BCInst; 527 528 for (unsigned i = 0, e = NewElts.size(); i != e; ++i) { 529 // If this is a memcpy/memmove, emit a GEP of the other element address. 530 Value *OtherElt = 0; 531 if (OtherPtr) { 532 OtherElt = new GetElementPtrInst(OtherPtr, Zero, 533 ConstantInt::get(Type::Int32Ty, i), 534 OtherPtr->getNameStr()+"."+utostr(i), 535 MI); 536 } 537 538 Value *EltPtr = NewElts[i]; 539 const Type *EltTy =cast<PointerType>(EltPtr->getType())->getElementType(); 540 541 // If we got down to a scalar, insert a load or store as appropriate. 542 if (EltTy->isFirstClassType()) { 543 if (isa<MemCpyInst>(MI) || isa<MemMoveInst>(MI)) { 544 Value *Elt = new LoadInst(SROADest ? OtherElt : EltPtr, "tmp", 545 MI); 546 new StoreInst(Elt, SROADest ? EltPtr : OtherElt, MI); 547 continue; 548 } else { 549 assert(isa<MemSetInst>(MI)); 550 551 // If the stored element is zero (common case), just store a null 552 // constant. 553 Constant *StoreVal; 554 if (ConstantInt *CI = dyn_cast<ConstantInt>(MI->getOperand(2))) { 555 if (CI->isZero()) { 556 StoreVal = Constant::getNullValue(EltTy); // 0.0, null, 0, <0,0> 557 } else { 558 // If EltTy is a packed type, get the element type. 559 const Type *ValTy = EltTy; 560 if (const VectorType *VTy = dyn_cast<VectorType>(ValTy)) 561 ValTy = VTy->getElementType(); 562 563 // Construct an integer with the right value. 564 unsigned EltSize = TD.getTypeSize(ValTy); 565 APInt OneVal(EltSize*8, CI->getZExtValue()); 566 APInt TotalVal(OneVal); 567 // Set each byte. 568 for (unsigned i = 0; i != EltSize-1; ++i) { 569 TotalVal = TotalVal.shl(8); 570 TotalVal |= OneVal; 571 } 572 573 // Convert the integer value to the appropriate type. 574 StoreVal = ConstantInt::get(TotalVal); 575 if (isa<PointerType>(ValTy)) 576 StoreVal = ConstantExpr::getIntToPtr(StoreVal, ValTy); 577 else if (ValTy->isFloatingPoint()) 578 StoreVal = ConstantExpr::getBitCast(StoreVal, ValTy); 579 assert(StoreVal->getType() == ValTy && "Type mismatch!"); 580 581 // If the requested value was a vector constant, create it. 582 if (EltTy != ValTy) { 583 unsigned NumElts = cast<VectorType>(ValTy)->getNumElements(); 584 SmallVector<Constant*, 16> Elts(NumElts, StoreVal); 585 StoreVal = ConstantVector::get(&Elts[0], NumElts); 586 } 587 } 588 new StoreInst(StoreVal, EltPtr, MI); 589 continue; 590 } 591 // Otherwise, if we're storing a byte variable, use a memset call for 592 // this element. 593 } 594 } 595 596 // Cast the element pointer to BytePtrTy. 597 if (EltPtr->getType() != BytePtrTy) 598 EltPtr = new BitCastInst(EltPtr, BytePtrTy, EltPtr->getNameStr(), MI); 599 600 // Cast the other pointer (if we have one) to BytePtrTy. 601 if (OtherElt && OtherElt->getType() != BytePtrTy) 602 OtherElt = new BitCastInst(OtherElt, BytePtrTy,OtherElt->getNameStr(), 603 MI); 604 605 unsigned EltSize = TD.getTypeSize(EltTy); 606 607 // Finally, insert the meminst for this element. 608 if (isa<MemCpyInst>(MI) || isa<MemMoveInst>(MI)) { 609 Value *Ops[] = { 610 SROADest ? EltPtr : OtherElt, // Dest ptr 611 SROADest ? OtherElt : EltPtr, // Src ptr 612 ConstantInt::get(MI->getOperand(3)->getType(), EltSize), // Size 613 Zero // Align 614 }; 615 new CallInst(TheFn, Ops, 4, "", MI); 616 } else { 617 assert(isa<MemSetInst>(MI)); 618 Value *Ops[] = { 619 EltPtr, MI->getOperand(2), // Dest, Value, 620 ConstantInt::get(MI->getOperand(3)->getType(), EltSize), // Size 621 Zero // Align 622 }; 623 new CallInst(TheFn, Ops, 4, "", MI); 624 } 625 } 626 627 // Finally, MI is now dead, as we've modified its actions to occur on all of 628 // the elements of the aggregate. 629 ++UI; 630 MI->eraseFromParent(); 631 } 632} 633 634 635/// isSafeStructAllocaToScalarRepl - Check to see if the specified allocation of 636/// an aggregate can be broken down into elements. Return 0 if not, 3 if safe, 637/// or 1 if safe after canonicalization has been performed. 638/// 639int SROA::isSafeAllocaToScalarRepl(AllocationInst *AI) { 640 // Loop over the use list of the alloca. We can only transform it if all of 641 // the users are safe to transform. 642 // 643 int isSafe = 3; 644 for (Value::use_iterator I = AI->use_begin(), E = AI->use_end(); 645 I != E; ++I) { 646 isSafe &= isSafeUseOfAllocation(cast<Instruction>(*I), AI); 647 if (isSafe == 0) { 648 DOUT << "Cannot transform: " << *AI << " due to user: " << **I; 649 return 0; 650 } 651 } 652 // If we require cleanup, isSafe is now 1, otherwise it is 3. 653 return isSafe; 654} 655 656/// CanonicalizeAllocaUsers - If SROA reported that it can promote the specified 657/// allocation, but only if cleaned up, perform the cleanups required. 658void SROA::CanonicalizeAllocaUsers(AllocationInst *AI) { 659 // At this point, we know that the end result will be SROA'd and promoted, so 660 // we can insert ugly code if required so long as sroa+mem2reg will clean it 661 // up. 662 for (Value::use_iterator UI = AI->use_begin(), E = AI->use_end(); 663 UI != E; ) { 664 GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(*UI++); 665 if (!GEPI) continue; 666 gep_type_iterator I = gep_type_begin(GEPI); 667 ++I; 668 669 if (const ArrayType *AT = dyn_cast<ArrayType>(*I)) { 670 uint64_t NumElements = AT->getNumElements(); 671 672 if (!isa<ConstantInt>(I.getOperand())) { 673 if (NumElements == 1) { 674 GEPI->setOperand(2, Constant::getNullValue(Type::Int32Ty)); 675 } else { 676 assert(NumElements == 2 && "Unhandled case!"); 677 // All users of the GEP must be loads. At each use of the GEP, insert 678 // two loads of the appropriate indexed GEP and select between them. 679 Value *IsOne = new ICmpInst(ICmpInst::ICMP_NE, I.getOperand(), 680 Constant::getNullValue(I.getOperand()->getType()), 681 "isone", GEPI); 682 // Insert the new GEP instructions, which are properly indexed. 683 SmallVector<Value*, 8> Indices(GEPI->op_begin()+1, GEPI->op_end()); 684 Indices[1] = Constant::getNullValue(Type::Int32Ty); 685 Value *ZeroIdx = new GetElementPtrInst(GEPI->getOperand(0), 686 &Indices[0], Indices.size(), 687 GEPI->getName()+".0", GEPI); 688 Indices[1] = ConstantInt::get(Type::Int32Ty, 1); 689 Value *OneIdx = new GetElementPtrInst(GEPI->getOperand(0), 690 &Indices[0], Indices.size(), 691 GEPI->getName()+".1", GEPI); 692 // Replace all loads of the variable index GEP with loads from both 693 // indexes and a select. 694 while (!GEPI->use_empty()) { 695 LoadInst *LI = cast<LoadInst>(GEPI->use_back()); 696 Value *Zero = new LoadInst(ZeroIdx, LI->getName()+".0", LI); 697 Value *One = new LoadInst(OneIdx , LI->getName()+".1", LI); 698 Value *R = new SelectInst(IsOne, One, Zero, LI->getName(), LI); 699 LI->replaceAllUsesWith(R); 700 LI->eraseFromParent(); 701 } 702 GEPI->eraseFromParent(); 703 } 704 } 705 } 706 } 707} 708 709/// MergeInType - Add the 'In' type to the accumulated type so far. If the 710/// types are incompatible, return true, otherwise update Accum and return 711/// false. 712/// 713/// There are three cases we handle here: 714/// 1) An effectively-integer union, where the pieces are stored into as 715/// smaller integers (common with byte swap and other idioms). 716/// 2) A union of vector types of the same size and potentially its elements. 717/// Here we turn element accesses into insert/extract element operations. 718/// 3) A union of scalar types, such as int/float or int/pointer. Here we 719/// merge together into integers, allowing the xform to work with #1 as 720/// well. 721static bool MergeInType(const Type *In, const Type *&Accum, 722 const TargetData &TD) { 723 // If this is our first type, just use it. 724 const VectorType *PTy; 725 if (Accum == Type::VoidTy || In == Accum) { 726 Accum = In; 727 } else if (In == Type::VoidTy) { 728 // Noop. 729 } else if (In->isInteger() && Accum->isInteger()) { // integer union. 730 // Otherwise pick whichever type is larger. 731 if (cast<IntegerType>(In)->getBitWidth() > 732 cast<IntegerType>(Accum)->getBitWidth()) 733 Accum = In; 734 } else if (isa<PointerType>(In) && isa<PointerType>(Accum)) { 735 // Pointer unions just stay as one of the pointers. 736 } else if (isa<VectorType>(In) || isa<VectorType>(Accum)) { 737 if ((PTy = dyn_cast<VectorType>(Accum)) && 738 PTy->getElementType() == In) { 739 // Accum is a vector, and we are accessing an element: ok. 740 } else if ((PTy = dyn_cast<VectorType>(In)) && 741 PTy->getElementType() == Accum) { 742 // In is a vector, and accum is an element: ok, remember In. 743 Accum = In; 744 } else if ((PTy = dyn_cast<VectorType>(In)) && isa<VectorType>(Accum) && 745 PTy->getBitWidth() == cast<VectorType>(Accum)->getBitWidth()) { 746 // Two vectors of the same size: keep Accum. 747 } else { 748 // Cannot insert an short into a <4 x int> or handle 749 // <2 x int> -> <4 x int> 750 return true; 751 } 752 } else { 753 // Pointer/FP/Integer unions merge together as integers. 754 switch (Accum->getTypeID()) { 755 case Type::PointerTyID: Accum = TD.getIntPtrType(); break; 756 case Type::FloatTyID: Accum = Type::Int32Ty; break; 757 case Type::DoubleTyID: Accum = Type::Int64Ty; break; 758 default: 759 assert(Accum->isInteger() && "Unknown FP type!"); 760 break; 761 } 762 763 switch (In->getTypeID()) { 764 case Type::PointerTyID: In = TD.getIntPtrType(); break; 765 case Type::FloatTyID: In = Type::Int32Ty; break; 766 case Type::DoubleTyID: In = Type::Int64Ty; break; 767 default: 768 assert(In->isInteger() && "Unknown FP type!"); 769 break; 770 } 771 return MergeInType(In, Accum, TD); 772 } 773 return false; 774} 775 776/// getUIntAtLeastAsBitAs - Return an unsigned integer type that is at least 777/// as big as the specified type. If there is no suitable type, this returns 778/// null. 779const Type *getUIntAtLeastAsBitAs(unsigned NumBits) { 780 if (NumBits > 64) return 0; 781 if (NumBits > 32) return Type::Int64Ty; 782 if (NumBits > 16) return Type::Int32Ty; 783 if (NumBits > 8) return Type::Int16Ty; 784 return Type::Int8Ty; 785} 786 787/// CanConvertToScalar - V is a pointer. If we can convert the pointee to a 788/// single scalar integer type, return that type. Further, if the use is not 789/// a completely trivial use that mem2reg could promote, set IsNotTrivial. If 790/// there are no uses of this pointer, return Type::VoidTy to differentiate from 791/// failure. 792/// 793const Type *SROA::CanConvertToScalar(Value *V, bool &IsNotTrivial) { 794 const Type *UsedType = Type::VoidTy; // No uses, no forced type. 795 const TargetData &TD = getAnalysis<TargetData>(); 796 const PointerType *PTy = cast<PointerType>(V->getType()); 797 798 for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI!=E; ++UI) { 799 Instruction *User = cast<Instruction>(*UI); 800 801 if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 802 if (MergeInType(LI->getType(), UsedType, TD)) 803 return 0; 804 805 } else if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 806 // Storing the pointer, not into the value? 807 if (SI->getOperand(0) == V) return 0; 808 809 // NOTE: We could handle storing of FP imms into integers here! 810 811 if (MergeInType(SI->getOperand(0)->getType(), UsedType, TD)) 812 return 0; 813 } else if (BitCastInst *CI = dyn_cast<BitCastInst>(User)) { 814 IsNotTrivial = true; 815 const Type *SubTy = CanConvertToScalar(CI, IsNotTrivial); 816 if (!SubTy || MergeInType(SubTy, UsedType, TD)) return 0; 817 } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) { 818 // Check to see if this is stepping over an element: GEP Ptr, int C 819 if (GEP->getNumOperands() == 2 && isa<ConstantInt>(GEP->getOperand(1))) { 820 unsigned Idx = cast<ConstantInt>(GEP->getOperand(1))->getZExtValue(); 821 unsigned ElSize = TD.getTypeSize(PTy->getElementType()); 822 unsigned BitOffset = Idx*ElSize*8; 823 if (BitOffset > 64 || !isPowerOf2_32(ElSize)) return 0; 824 825 IsNotTrivial = true; 826 const Type *SubElt = CanConvertToScalar(GEP, IsNotTrivial); 827 if (SubElt == 0) return 0; 828 if (SubElt != Type::VoidTy && SubElt->isInteger()) { 829 const Type *NewTy = 830 getUIntAtLeastAsBitAs(TD.getTypeSize(SubElt)*8+BitOffset); 831 if (NewTy == 0 || MergeInType(NewTy, UsedType, TD)) return 0; 832 continue; 833 } 834 } else if (GEP->getNumOperands() == 3 && 835 isa<ConstantInt>(GEP->getOperand(1)) && 836 isa<ConstantInt>(GEP->getOperand(2)) && 837 cast<ConstantInt>(GEP->getOperand(1))->isZero()) { 838 // We are stepping into an element, e.g. a structure or an array: 839 // GEP Ptr, int 0, uint C 840 const Type *AggTy = PTy->getElementType(); 841 unsigned Idx = cast<ConstantInt>(GEP->getOperand(2))->getZExtValue(); 842 843 if (const ArrayType *ATy = dyn_cast<ArrayType>(AggTy)) { 844 if (Idx >= ATy->getNumElements()) return 0; // Out of range. 845 } else if (const VectorType *VectorTy = dyn_cast<VectorType>(AggTy)) { 846 // Getting an element of the packed vector. 847 if (Idx >= VectorTy->getNumElements()) return 0; // Out of range. 848 849 // Merge in the vector type. 850 if (MergeInType(VectorTy, UsedType, TD)) return 0; 851 852 const Type *SubTy = CanConvertToScalar(GEP, IsNotTrivial); 853 if (SubTy == 0) return 0; 854 855 if (SubTy != Type::VoidTy && MergeInType(SubTy, UsedType, TD)) 856 return 0; 857 858 // We'll need to change this to an insert/extract element operation. 859 IsNotTrivial = true; 860 continue; // Everything looks ok 861 862 } else if (isa<StructType>(AggTy)) { 863 // Structs are always ok. 864 } else { 865 return 0; 866 } 867 const Type *NTy = getUIntAtLeastAsBitAs(TD.getTypeSize(AggTy)*8); 868 if (NTy == 0 || MergeInType(NTy, UsedType, TD)) return 0; 869 const Type *SubTy = CanConvertToScalar(GEP, IsNotTrivial); 870 if (SubTy == 0) return 0; 871 if (SubTy != Type::VoidTy && MergeInType(SubTy, UsedType, TD)) 872 return 0; 873 continue; // Everything looks ok 874 } 875 return 0; 876 } else { 877 // Cannot handle this! 878 return 0; 879 } 880 } 881 882 return UsedType; 883} 884 885/// ConvertToScalar - The specified alloca passes the CanConvertToScalar 886/// predicate and is non-trivial. Convert it to something that can be trivially 887/// promoted into a register by mem2reg. 888void SROA::ConvertToScalar(AllocationInst *AI, const Type *ActualTy) { 889 DOUT << "CONVERT TO SCALAR: " << *AI << " TYPE = " 890 << *ActualTy << "\n"; 891 ++NumConverted; 892 893 BasicBlock *EntryBlock = AI->getParent(); 894 assert(EntryBlock == &EntryBlock->getParent()->getEntryBlock() && 895 "Not in the entry block!"); 896 EntryBlock->getInstList().remove(AI); // Take the alloca out of the program. 897 898 // Create and insert the alloca. 899 AllocaInst *NewAI = new AllocaInst(ActualTy, 0, AI->getName(), 900 EntryBlock->begin()); 901 ConvertUsesToScalar(AI, NewAI, 0); 902 delete AI; 903} 904 905 906/// ConvertUsesToScalar - Convert all of the users of Ptr to use the new alloca 907/// directly. This happens when we are converting an "integer union" to a 908/// single integer scalar, or when we are converting a "vector union" to a 909/// vector with insert/extractelement instructions. 910/// 911/// Offset is an offset from the original alloca, in bits that need to be 912/// shifted to the right. By the end of this, there should be no uses of Ptr. 913void SROA::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, unsigned Offset) { 914 const TargetData &TD = getAnalysis<TargetData>(); 915 while (!Ptr->use_empty()) { 916 Instruction *User = cast<Instruction>(Ptr->use_back()); 917 918 if (LoadInst *LI = dyn_cast<LoadInst>(User)) { 919 // The load is a bit extract from NewAI shifted right by Offset bits. 920 Value *NV = new LoadInst(NewAI, LI->getName(), LI); 921 if (NV->getType() == LI->getType()) { 922 // We win, no conversion needed. 923 } else if (const VectorType *PTy = dyn_cast<VectorType>(NV->getType())) { 924 // If the result alloca is a vector type, this is either an element 925 // access or a bitcast to another vector type. 926 if (isa<VectorType>(LI->getType())) { 927 NV = new BitCastInst(NV, LI->getType(), LI->getName(), LI); 928 } else { 929 // Must be an element access. 930 unsigned Elt = Offset/(TD.getTypeSize(PTy->getElementType())*8); 931 NV = new ExtractElementInst( 932 NV, ConstantInt::get(Type::Int32Ty, Elt), "tmp", LI); 933 } 934 } else if (isa<PointerType>(NV->getType())) { 935 assert(isa<PointerType>(LI->getType())); 936 // Must be ptr->ptr cast. Anything else would result in NV being 937 // an integer. 938 NV = new BitCastInst(NV, LI->getType(), LI->getName(), LI); 939 } else { 940 const IntegerType *NTy = cast<IntegerType>(NV->getType()); 941 unsigned LIBitWidth = TD.getTypeSizeInBits(LI->getType()); 942 943 // If this is a big-endian system and the load is narrower than the 944 // full alloca type, we need to do a shift to get the right bits. 945 int ShAmt = 0; 946 if (TD.isBigEndian()) { 947 ShAmt = NTy->getBitWidth()-LIBitWidth-Offset; 948 } else { 949 ShAmt = Offset; 950 } 951 952 // Note: we support negative bitwidths (with shl) which are not defined. 953 // We do this to support (f.e.) loads off the end of a structure where 954 // only some bits are used. 955 if (ShAmt > 0 && (unsigned)ShAmt < NTy->getBitWidth()) 956 NV = BinaryOperator::createLShr(NV, 957 ConstantInt::get(NV->getType(),ShAmt), 958 LI->getName(), LI); 959 else if (ShAmt < 0 && (unsigned)-ShAmt < NTy->getBitWidth()) 960 NV = BinaryOperator::createShl(NV, 961 ConstantInt::get(NV->getType(),-ShAmt), 962 LI->getName(), LI); 963 964 // Finally, unconditionally truncate the integer to the right width. 965 if (LIBitWidth < NTy->getBitWidth()) 966 NV = new TruncInst(NV, IntegerType::get(LIBitWidth), 967 LI->getName(), LI); 968 969 // If the result is an integer, this is a trunc or bitcast. 970 if (isa<IntegerType>(LI->getType())) { 971 assert(NV->getType() == LI->getType() && "Truncate wasn't enough?"); 972 } else if (LI->getType()->isFloatingPoint()) { 973 // Just do a bitcast, we know the sizes match up. 974 NV = new BitCastInst(NV, LI->getType(), LI->getName(), LI); 975 } else { 976 // Otherwise must be a pointer. 977 NV = new IntToPtrInst(NV, LI->getType(), LI->getName(), LI); 978 } 979 } 980 LI->replaceAllUsesWith(NV); 981 LI->eraseFromParent(); 982 } else if (StoreInst *SI = dyn_cast<StoreInst>(User)) { 983 assert(SI->getOperand(0) != Ptr && "Consistency error!"); 984 985 // Convert the stored type to the actual type, shift it left to insert 986 // then 'or' into place. 987 Value *SV = SI->getOperand(0); 988 const Type *AllocaType = NewAI->getType()->getElementType(); 989 if (SV->getType() == AllocaType) { 990 // All is well. 991 } else if (const VectorType *PTy = dyn_cast<VectorType>(AllocaType)) { 992 Value *Old = new LoadInst(NewAI, NewAI->getName()+".in", SI); 993 994 // If the result alloca is a vector type, this is either an element 995 // access or a bitcast to another vector type. 996 if (isa<VectorType>(SV->getType())) { 997 SV = new BitCastInst(SV, AllocaType, SV->getName(), SI); 998 } else { 999 // Must be an element insertion. 1000 unsigned Elt = Offset/(TD.getTypeSize(PTy->getElementType())*8); 1001 SV = new InsertElementInst(Old, SV, 1002 ConstantInt::get(Type::Int32Ty, Elt), 1003 "tmp", SI); 1004 } 1005 } else if (isa<PointerType>(AllocaType)) { 1006 // If the alloca type is a pointer, then all the elements must be 1007 // pointers. 1008 if (SV->getType() != AllocaType) 1009 SV = new BitCastInst(SV, AllocaType, SV->getName(), SI); 1010 } else { 1011 Value *Old = new LoadInst(NewAI, NewAI->getName()+".in", SI); 1012 1013 // If SV is a float, convert it to the appropriate integer type. 1014 // If it is a pointer, do the same, and also handle ptr->ptr casts 1015 // here. 1016 unsigned SrcWidth = TD.getTypeSizeInBits(SV->getType()); 1017 unsigned DestWidth = AllocaType->getPrimitiveSizeInBits(); 1018 if (SV->getType()->isFloatingPoint()) 1019 SV = new BitCastInst(SV, IntegerType::get(SrcWidth), 1020 SV->getName(), SI); 1021 else if (isa<PointerType>(SV->getType())) 1022 SV = new PtrToIntInst(SV, TD.getIntPtrType(), SV->getName(), SI); 1023 1024 // Always zero extend the value if needed. 1025 if (SV->getType() != AllocaType) 1026 SV = new ZExtInst(SV, AllocaType, SV->getName(), SI); 1027 1028 // If this is a big-endian system and the store is narrower than the 1029 // full alloca type, we need to do a shift to get the right bits. 1030 int ShAmt = 0; 1031 if (TD.isBigEndian()) { 1032 ShAmt = DestWidth-SrcWidth-Offset; 1033 } else { 1034 ShAmt = Offset; 1035 } 1036 1037 // Note: we support negative bitwidths (with shr) which are not defined. 1038 // We do this to support (f.e.) stores off the end of a structure where 1039 // only some bits in the structure are set. 1040 APInt Mask(APInt::getLowBitsSet(DestWidth, SrcWidth)); 1041 if (ShAmt > 0 && (unsigned)ShAmt < DestWidth) { 1042 SV = BinaryOperator::createShl(SV, 1043 ConstantInt::get(SV->getType(), ShAmt), 1044 SV->getName(), SI); 1045 Mask <<= ShAmt; 1046 } else if (ShAmt < 0 && (unsigned)-ShAmt < DestWidth) { 1047 SV = BinaryOperator::createLShr(SV, 1048 ConstantInt::get(SV->getType(),-ShAmt), 1049 SV->getName(), SI); 1050 Mask = Mask.lshr(ShAmt); 1051 } 1052 1053 // Mask out the bits we are about to insert from the old value, and or 1054 // in the new bits. 1055 if (SrcWidth != DestWidth) { 1056 assert(DestWidth > SrcWidth); 1057 Old = BinaryOperator::createAnd(Old, ConstantInt::get(~Mask), 1058 Old->getName()+".mask", SI); 1059 SV = BinaryOperator::createOr(Old, SV, SV->getName()+".ins", SI); 1060 } 1061 } 1062 new StoreInst(SV, NewAI, SI); 1063 SI->eraseFromParent(); 1064 1065 } else if (BitCastInst *CI = dyn_cast<BitCastInst>(User)) { 1066 ConvertUsesToScalar(CI, NewAI, Offset); 1067 CI->eraseFromParent(); 1068 } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) { 1069 const PointerType *AggPtrTy = 1070 cast<PointerType>(GEP->getOperand(0)->getType()); 1071 const TargetData &TD = getAnalysis<TargetData>(); 1072 unsigned AggSizeInBits = TD.getTypeSize(AggPtrTy->getElementType())*8; 1073 1074 // Check to see if this is stepping over an element: GEP Ptr, int C 1075 unsigned NewOffset = Offset; 1076 if (GEP->getNumOperands() == 2) { 1077 unsigned Idx = cast<ConstantInt>(GEP->getOperand(1))->getZExtValue(); 1078 unsigned BitOffset = Idx*AggSizeInBits; 1079 1080 NewOffset += BitOffset; 1081 } else if (GEP->getNumOperands() == 3) { 1082 // We know that operand #2 is zero. 1083 unsigned Idx = cast<ConstantInt>(GEP->getOperand(2))->getZExtValue(); 1084 const Type *AggTy = AggPtrTy->getElementType(); 1085 if (const SequentialType *SeqTy = dyn_cast<SequentialType>(AggTy)) { 1086 unsigned ElSizeBits = TD.getTypeSize(SeqTy->getElementType())*8; 1087 1088 NewOffset += ElSizeBits*Idx; 1089 } else if (const StructType *STy = dyn_cast<StructType>(AggTy)) { 1090 unsigned EltBitOffset = 1091 TD.getStructLayout(STy)->getElementOffset(Idx)*8; 1092 1093 NewOffset += EltBitOffset; 1094 } else { 1095 assert(0 && "Unsupported operation!"); 1096 abort(); 1097 } 1098 } else { 1099 assert(0 && "Unsupported operation!"); 1100 abort(); 1101 } 1102 ConvertUsesToScalar(GEP, NewAI, NewOffset); 1103 GEP->eraseFromParent(); 1104 } else { 1105 assert(0 && "Unsupported operation!"); 1106 abort(); 1107 } 1108 } 1109} 1110