1 //===--- CGAtomic.cpp - Emit LLVM IR for atomic operations ----------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file contains the code for emitting atomic operations. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "CGCall.h" 14 #include "CGRecordLayout.h" 15 #include "CodeGenFunction.h" 16 #include "CodeGenModule.h" 17 #include "TargetInfo.h" 18 #include "clang/AST/ASTContext.h" 19 #include "clang/CodeGen/CGFunctionInfo.h" 20 #include "clang/Frontend/FrontendDiagnostic.h" 21 #include "llvm/ADT/DenseMap.h" 22 #include "llvm/IR/DataLayout.h" 23 #include "llvm/IR/Intrinsics.h" 24 #include "llvm/IR/Operator.h" 25 26 using namespace clang; 27 using namespace CodeGen; 28 29 namespace { 30 class AtomicInfo { 31 CodeGenFunction &CGF; 32 QualType AtomicTy; 33 QualType ValueTy; 34 uint64_t AtomicSizeInBits; 35 uint64_t ValueSizeInBits; 36 CharUnits AtomicAlign; 37 CharUnits ValueAlign; 38 TypeEvaluationKind EvaluationKind; 39 bool UseLibcall; 40 LValue LVal; 41 CGBitFieldInfo BFI; 42 public: 43 AtomicInfo(CodeGenFunction &CGF, LValue &lvalue) 44 : CGF(CGF), AtomicSizeInBits(0), ValueSizeInBits(0), 45 EvaluationKind(TEK_Scalar), UseLibcall(true) { 46 assert(!lvalue.isGlobalReg()); 47 ASTContext &C = CGF.getContext(); 48 if (lvalue.isSimple()) { 49 AtomicTy = lvalue.getType(); 50 if (auto *ATy = AtomicTy->getAs<AtomicType>()) 51 ValueTy = ATy->getValueType(); 52 else 53 ValueTy = AtomicTy; 54 EvaluationKind = CGF.getEvaluationKind(ValueTy); 55 56 uint64_t ValueAlignInBits; 57 uint64_t AtomicAlignInBits; 58 TypeInfo ValueTI = C.getTypeInfo(ValueTy); 59 ValueSizeInBits = ValueTI.Width; 60 ValueAlignInBits = ValueTI.Align; 61 62 TypeInfo AtomicTI = C.getTypeInfo(AtomicTy); 63 AtomicSizeInBits = AtomicTI.Width; 64 AtomicAlignInBits = AtomicTI.Align; 65 66 assert(ValueSizeInBits <= AtomicSizeInBits); 67 assert(ValueAlignInBits <= AtomicAlignInBits); 68 69 AtomicAlign = C.toCharUnitsFromBits(AtomicAlignInBits); 70 ValueAlign = C.toCharUnitsFromBits(ValueAlignInBits); 71 if (lvalue.getAlignment().isZero()) 72 lvalue.setAlignment(AtomicAlign); 73 74 LVal = lvalue; 75 } else if (lvalue.isBitField()) { 76 ValueTy = lvalue.getType(); 77 ValueSizeInBits = C.getTypeSize(ValueTy); 78 auto &OrigBFI = lvalue.getBitFieldInfo(); 79 auto Offset = OrigBFI.Offset % C.toBits(lvalue.getAlignment()); 80 AtomicSizeInBits = C.toBits( 81 C.toCharUnitsFromBits(Offset + OrigBFI.Size + C.getCharWidth() - 1) 82 .alignTo(lvalue.getAlignment())); 83 auto VoidPtrAddr = CGF.EmitCastToVoidPtr(lvalue.getBitFieldPointer()); 84 auto OffsetInChars = 85 (C.toCharUnitsFromBits(OrigBFI.Offset) / lvalue.getAlignment()) * 86 lvalue.getAlignment(); 87 VoidPtrAddr = CGF.Builder.CreateConstGEP1_64( 88 VoidPtrAddr, OffsetInChars.getQuantity()); 89 auto Addr = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast( 90 VoidPtrAddr, 91 CGF.Builder.getIntNTy(AtomicSizeInBits)->getPointerTo(), 92 "atomic_bitfield_base"); 93 BFI = OrigBFI; 94 BFI.Offset = Offset; 95 BFI.StorageSize = AtomicSizeInBits; 96 BFI.StorageOffset += OffsetInChars; 97 LVal = LValue::MakeBitfield(Address(Addr, lvalue.getAlignment()), 98 BFI, lvalue.getType(), lvalue.getBaseInfo(), 99 lvalue.getTBAAInfo()); 100 AtomicTy = C.getIntTypeForBitwidth(AtomicSizeInBits, OrigBFI.IsSigned); 101 if (AtomicTy.isNull()) { 102 llvm::APInt Size( 103 /*numBits=*/32, 104 C.toCharUnitsFromBits(AtomicSizeInBits).getQuantity()); 105 AtomicTy = 106 C.getConstantArrayType(C.CharTy, Size, nullptr, ArrayType::Normal, 107 /*IndexTypeQuals=*/0); 108 } 109 AtomicAlign = ValueAlign = lvalue.getAlignment(); 110 } else if (lvalue.isVectorElt()) { 111 ValueTy = lvalue.getType()->castAs<VectorType>()->getElementType(); 112 ValueSizeInBits = C.getTypeSize(ValueTy); 113 AtomicTy = lvalue.getType(); 114 AtomicSizeInBits = C.getTypeSize(AtomicTy); 115 AtomicAlign = ValueAlign = lvalue.getAlignment(); 116 LVal = lvalue; 117 } else { 118 assert(lvalue.isExtVectorElt()); 119 ValueTy = lvalue.getType(); 120 ValueSizeInBits = C.getTypeSize(ValueTy); 121 AtomicTy = ValueTy = CGF.getContext().getExtVectorType( 122 lvalue.getType(), cast<llvm::FixedVectorType>( 123 lvalue.getExtVectorAddress().getElementType()) 124 ->getNumElements()); 125 AtomicSizeInBits = C.getTypeSize(AtomicTy); 126 AtomicAlign = ValueAlign = lvalue.getAlignment(); 127 LVal = lvalue; 128 } 129 UseLibcall = !C.getTargetInfo().hasBuiltinAtomic( 130 AtomicSizeInBits, C.toBits(lvalue.getAlignment())); 131 } 132 133 QualType getAtomicType() const { return AtomicTy; } 134 QualType getValueType() const { return ValueTy; } 135 CharUnits getAtomicAlignment() const { return AtomicAlign; } 136 uint64_t getAtomicSizeInBits() const { return AtomicSizeInBits; } 137 uint64_t getValueSizeInBits() const { return ValueSizeInBits; } 138 TypeEvaluationKind getEvaluationKind() const { return EvaluationKind; } 139 bool shouldUseLibcall() const { return UseLibcall; } 140 const LValue &getAtomicLValue() const { return LVal; } 141 llvm::Value *getAtomicPointer() const { 142 if (LVal.isSimple()) 143 return LVal.getPointer(CGF); 144 else if (LVal.isBitField()) 145 return LVal.getBitFieldPointer(); 146 else if (LVal.isVectorElt()) 147 return LVal.getVectorPointer(); 148 assert(LVal.isExtVectorElt()); 149 return LVal.getExtVectorPointer(); 150 } 151 Address getAtomicAddress() const { 152 return Address(getAtomicPointer(), getAtomicAlignment()); 153 } 154 155 Address getAtomicAddressAsAtomicIntPointer() const { 156 return emitCastToAtomicIntPointer(getAtomicAddress()); 157 } 158 159 /// Is the atomic size larger than the underlying value type? 160 /// 161 /// Note that the absence of padding does not mean that atomic 162 /// objects are completely interchangeable with non-atomic 163 /// objects: we might have promoted the alignment of a type 164 /// without making it bigger. 165 bool hasPadding() const { 166 return (ValueSizeInBits != AtomicSizeInBits); 167 } 168 169 bool emitMemSetZeroIfNecessary() const; 170 171 llvm::Value *getAtomicSizeValue() const { 172 CharUnits size = CGF.getContext().toCharUnitsFromBits(AtomicSizeInBits); 173 return CGF.CGM.getSize(size); 174 } 175 176 /// Cast the given pointer to an integer pointer suitable for atomic 177 /// operations if the source. 178 Address emitCastToAtomicIntPointer(Address Addr) const; 179 180 /// If Addr is compatible with the iN that will be used for an atomic 181 /// operation, bitcast it. Otherwise, create a temporary that is suitable 182 /// and copy the value across. 183 Address convertToAtomicIntPointer(Address Addr) const; 184 185 /// Turn an atomic-layout object into an r-value. 186 RValue convertAtomicTempToRValue(Address addr, AggValueSlot resultSlot, 187 SourceLocation loc, bool AsValue) const; 188 189 /// Converts a rvalue to integer value. 190 llvm::Value *convertRValueToInt(RValue RVal) const; 191 192 RValue ConvertIntToValueOrAtomic(llvm::Value *IntVal, 193 AggValueSlot ResultSlot, 194 SourceLocation Loc, bool AsValue) const; 195 196 /// Copy an atomic r-value into atomic-layout memory. 197 void emitCopyIntoMemory(RValue rvalue) const; 198 199 /// Project an l-value down to the value field. 200 LValue projectValue() const { 201 assert(LVal.isSimple()); 202 Address addr = getAtomicAddress(); 203 if (hasPadding()) 204 addr = CGF.Builder.CreateStructGEP(addr, 0); 205 206 return LValue::MakeAddr(addr, getValueType(), CGF.getContext(), 207 LVal.getBaseInfo(), LVal.getTBAAInfo()); 208 } 209 210 /// Emits atomic load. 211 /// \returns Loaded value. 212 RValue EmitAtomicLoad(AggValueSlot ResultSlot, SourceLocation Loc, 213 bool AsValue, llvm::AtomicOrdering AO, 214 bool IsVolatile); 215 216 /// Emits atomic compare-and-exchange sequence. 217 /// \param Expected Expected value. 218 /// \param Desired Desired value. 219 /// \param Success Atomic ordering for success operation. 220 /// \param Failure Atomic ordering for failed operation. 221 /// \param IsWeak true if atomic operation is weak, false otherwise. 222 /// \returns Pair of values: previous value from storage (value type) and 223 /// boolean flag (i1 type) with true if success and false otherwise. 224 std::pair<RValue, llvm::Value *> 225 EmitAtomicCompareExchange(RValue Expected, RValue Desired, 226 llvm::AtomicOrdering Success = 227 llvm::AtomicOrdering::SequentiallyConsistent, 228 llvm::AtomicOrdering Failure = 229 llvm::AtomicOrdering::SequentiallyConsistent, 230 bool IsWeak = false); 231 232 /// Emits atomic update. 233 /// \param AO Atomic ordering. 234 /// \param UpdateOp Update operation for the current lvalue. 235 void EmitAtomicUpdate(llvm::AtomicOrdering AO, 236 const llvm::function_ref<RValue(RValue)> &UpdateOp, 237 bool IsVolatile); 238 /// Emits atomic update. 239 /// \param AO Atomic ordering. 240 void EmitAtomicUpdate(llvm::AtomicOrdering AO, RValue UpdateRVal, 241 bool IsVolatile); 242 243 /// Materialize an atomic r-value in atomic-layout memory. 244 Address materializeRValue(RValue rvalue) const; 245 246 /// Creates temp alloca for intermediate operations on atomic value. 247 Address CreateTempAlloca() const; 248 private: 249 bool requiresMemSetZero(llvm::Type *type) const; 250 251 252 /// Emits atomic load as a libcall. 253 void EmitAtomicLoadLibcall(llvm::Value *AddForLoaded, 254 llvm::AtomicOrdering AO, bool IsVolatile); 255 /// Emits atomic load as LLVM instruction. 256 llvm::Value *EmitAtomicLoadOp(llvm::AtomicOrdering AO, bool IsVolatile); 257 /// Emits atomic compare-and-exchange op as a libcall. 258 llvm::Value *EmitAtomicCompareExchangeLibcall( 259 llvm::Value *ExpectedAddr, llvm::Value *DesiredAddr, 260 llvm::AtomicOrdering Success = 261 llvm::AtomicOrdering::SequentiallyConsistent, 262 llvm::AtomicOrdering Failure = 263 llvm::AtomicOrdering::SequentiallyConsistent); 264 /// Emits atomic compare-and-exchange op as LLVM instruction. 265 std::pair<llvm::Value *, llvm::Value *> EmitAtomicCompareExchangeOp( 266 llvm::Value *ExpectedVal, llvm::Value *DesiredVal, 267 llvm::AtomicOrdering Success = 268 llvm::AtomicOrdering::SequentiallyConsistent, 269 llvm::AtomicOrdering Failure = 270 llvm::AtomicOrdering::SequentiallyConsistent, 271 bool IsWeak = false); 272 /// Emit atomic update as libcalls. 273 void 274 EmitAtomicUpdateLibcall(llvm::AtomicOrdering AO, 275 const llvm::function_ref<RValue(RValue)> &UpdateOp, 276 bool IsVolatile); 277 /// Emit atomic update as LLVM instructions. 278 void EmitAtomicUpdateOp(llvm::AtomicOrdering AO, 279 const llvm::function_ref<RValue(RValue)> &UpdateOp, 280 bool IsVolatile); 281 /// Emit atomic update as libcalls. 282 void EmitAtomicUpdateLibcall(llvm::AtomicOrdering AO, RValue UpdateRVal, 283 bool IsVolatile); 284 /// Emit atomic update as LLVM instructions. 285 void EmitAtomicUpdateOp(llvm::AtomicOrdering AO, RValue UpdateRal, 286 bool IsVolatile); 287 }; 288 } 289 290 Address AtomicInfo::CreateTempAlloca() const { 291 Address TempAlloca = CGF.CreateMemTemp( 292 (LVal.isBitField() && ValueSizeInBits > AtomicSizeInBits) ? ValueTy 293 : AtomicTy, 294 getAtomicAlignment(), 295 "atomic-temp"); 296 // Cast to pointer to value type for bitfields. 297 if (LVal.isBitField()) 298 return CGF.Builder.CreatePointerBitCastOrAddrSpaceCast( 299 TempAlloca, getAtomicAddress().getType()); 300 return TempAlloca; 301 } 302 303 static RValue emitAtomicLibcall(CodeGenFunction &CGF, 304 StringRef fnName, 305 QualType resultType, 306 CallArgList &args) { 307 const CGFunctionInfo &fnInfo = 308 CGF.CGM.getTypes().arrangeBuiltinFunctionCall(resultType, args); 309 llvm::FunctionType *fnTy = CGF.CGM.getTypes().GetFunctionType(fnInfo); 310 llvm::AttrBuilder fnAttrB; 311 fnAttrB.addAttribute(llvm::Attribute::NoUnwind); 312 fnAttrB.addAttribute(llvm::Attribute::WillReturn); 313 llvm::AttributeList fnAttrs = llvm::AttributeList::get( 314 CGF.getLLVMContext(), llvm::AttributeList::FunctionIndex, fnAttrB); 315 316 llvm::FunctionCallee fn = 317 CGF.CGM.CreateRuntimeFunction(fnTy, fnName, fnAttrs); 318 auto callee = CGCallee::forDirect(fn); 319 return CGF.EmitCall(fnInfo, callee, ReturnValueSlot(), args); 320 } 321 322 /// Does a store of the given IR type modify the full expected width? 323 static bool isFullSizeType(CodeGenModule &CGM, llvm::Type *type, 324 uint64_t expectedSize) { 325 return (CGM.getDataLayout().getTypeStoreSize(type) * 8 == expectedSize); 326 } 327 328 /// Does the atomic type require memsetting to zero before initialization? 329 /// 330 /// The IR type is provided as a way of making certain queries faster. 331 bool AtomicInfo::requiresMemSetZero(llvm::Type *type) const { 332 // If the atomic type has size padding, we definitely need a memset. 333 if (hasPadding()) return true; 334 335 // Otherwise, do some simple heuristics to try to avoid it: 336 switch (getEvaluationKind()) { 337 // For scalars and complexes, check whether the store size of the 338 // type uses the full size. 339 case TEK_Scalar: 340 return !isFullSizeType(CGF.CGM, type, AtomicSizeInBits); 341 case TEK_Complex: 342 return !isFullSizeType(CGF.CGM, type->getStructElementType(0), 343 AtomicSizeInBits / 2); 344 345 // Padding in structs has an undefined bit pattern. User beware. 346 case TEK_Aggregate: 347 return false; 348 } 349 llvm_unreachable("bad evaluation kind"); 350 } 351 352 bool AtomicInfo::emitMemSetZeroIfNecessary() const { 353 assert(LVal.isSimple()); 354 llvm::Value *addr = LVal.getPointer(CGF); 355 if (!requiresMemSetZero(addr->getType()->getPointerElementType())) 356 return false; 357 358 CGF.Builder.CreateMemSet( 359 addr, llvm::ConstantInt::get(CGF.Int8Ty, 0), 360 CGF.getContext().toCharUnitsFromBits(AtomicSizeInBits).getQuantity(), 361 LVal.getAlignment().getAsAlign()); 362 return true; 363 } 364 365 static void emitAtomicCmpXchg(CodeGenFunction &CGF, AtomicExpr *E, bool IsWeak, 366 Address Dest, Address Ptr, 367 Address Val1, Address Val2, 368 uint64_t Size, 369 llvm::AtomicOrdering SuccessOrder, 370 llvm::AtomicOrdering FailureOrder, 371 llvm::SyncScope::ID Scope) { 372 // Note that cmpxchg doesn't support weak cmpxchg, at least at the moment. 373 llvm::Value *Expected = CGF.Builder.CreateLoad(Val1); 374 llvm::Value *Desired = CGF.Builder.CreateLoad(Val2); 375 376 llvm::AtomicCmpXchgInst *Pair = CGF.Builder.CreateAtomicCmpXchg( 377 Ptr.getPointer(), Expected, Desired, SuccessOrder, FailureOrder, 378 Scope); 379 Pair->setVolatile(E->isVolatile()); 380 Pair->setWeak(IsWeak); 381 382 // Cmp holds the result of the compare-exchange operation: true on success, 383 // false on failure. 384 llvm::Value *Old = CGF.Builder.CreateExtractValue(Pair, 0); 385 llvm::Value *Cmp = CGF.Builder.CreateExtractValue(Pair, 1); 386 387 // This basic block is used to hold the store instruction if the operation 388 // failed. 389 llvm::BasicBlock *StoreExpectedBB = 390 CGF.createBasicBlock("cmpxchg.store_expected", CGF.CurFn); 391 392 // This basic block is the exit point of the operation, we should end up 393 // here regardless of whether or not the operation succeeded. 394 llvm::BasicBlock *ContinueBB = 395 CGF.createBasicBlock("cmpxchg.continue", CGF.CurFn); 396 397 // Update Expected if Expected isn't equal to Old, otherwise branch to the 398 // exit point. 399 CGF.Builder.CreateCondBr(Cmp, ContinueBB, StoreExpectedBB); 400 401 CGF.Builder.SetInsertPoint(StoreExpectedBB); 402 // Update the memory at Expected with Old's value. 403 CGF.Builder.CreateStore(Old, Val1); 404 // Finally, branch to the exit point. 405 CGF.Builder.CreateBr(ContinueBB); 406 407 CGF.Builder.SetInsertPoint(ContinueBB); 408 // Update the memory at Dest with Cmp's value. 409 CGF.EmitStoreOfScalar(Cmp, CGF.MakeAddrLValue(Dest, E->getType())); 410 } 411 412 /// Given an ordering required on success, emit all possible cmpxchg 413 /// instructions to cope with the provided (but possibly only dynamically known) 414 /// FailureOrder. 415 static void emitAtomicCmpXchgFailureSet(CodeGenFunction &CGF, AtomicExpr *E, 416 bool IsWeak, Address Dest, Address Ptr, 417 Address Val1, Address Val2, 418 llvm::Value *FailureOrderVal, 419 uint64_t Size, 420 llvm::AtomicOrdering SuccessOrder, 421 llvm::SyncScope::ID Scope) { 422 llvm::AtomicOrdering FailureOrder; 423 if (llvm::ConstantInt *FO = dyn_cast<llvm::ConstantInt>(FailureOrderVal)) { 424 auto FOS = FO->getSExtValue(); 425 if (!llvm::isValidAtomicOrderingCABI(FOS)) 426 FailureOrder = llvm::AtomicOrdering::Monotonic; 427 else 428 switch ((llvm::AtomicOrderingCABI)FOS) { 429 case llvm::AtomicOrderingCABI::relaxed: 430 // 31.7.2.18: "The failure argument shall not be memory_order_release 431 // nor memory_order_acq_rel". Fallback to monotonic. 432 case llvm::AtomicOrderingCABI::release: 433 case llvm::AtomicOrderingCABI::acq_rel: 434 FailureOrder = llvm::AtomicOrdering::Monotonic; 435 break; 436 case llvm::AtomicOrderingCABI::consume: 437 case llvm::AtomicOrderingCABI::acquire: 438 FailureOrder = llvm::AtomicOrdering::Acquire; 439 break; 440 case llvm::AtomicOrderingCABI::seq_cst: 441 FailureOrder = llvm::AtomicOrdering::SequentiallyConsistent; 442 break; 443 } 444 // Prior to c++17, "the failure argument shall be no stronger than the 445 // success argument". This condition has been lifted and the only 446 // precondition is 31.7.2.18. Effectively treat this as a DR and skip 447 // language version checks. 448 emitAtomicCmpXchg(CGF, E, IsWeak, Dest, Ptr, Val1, Val2, Size, SuccessOrder, 449 FailureOrder, Scope); 450 return; 451 } 452 453 // Create all the relevant BB's 454 auto *MonotonicBB = CGF.createBasicBlock("monotonic_fail", CGF.CurFn); 455 auto *AcquireBB = CGF.createBasicBlock("acquire_fail", CGF.CurFn); 456 auto *SeqCstBB = CGF.createBasicBlock("seqcst_fail", CGF.CurFn); 457 auto *ContBB = CGF.createBasicBlock("atomic.continue", CGF.CurFn); 458 459 // MonotonicBB is arbitrarily chosen as the default case; in practice, this 460 // doesn't matter unless someone is crazy enough to use something that 461 // doesn't fold to a constant for the ordering. 462 llvm::SwitchInst *SI = CGF.Builder.CreateSwitch(FailureOrderVal, MonotonicBB); 463 // Implemented as acquire, since it's the closest in LLVM. 464 SI->addCase(CGF.Builder.getInt32((int)llvm::AtomicOrderingCABI::consume), 465 AcquireBB); 466 SI->addCase(CGF.Builder.getInt32((int)llvm::AtomicOrderingCABI::acquire), 467 AcquireBB); 468 SI->addCase(CGF.Builder.getInt32((int)llvm::AtomicOrderingCABI::seq_cst), 469 SeqCstBB); 470 471 // Emit all the different atomics 472 CGF.Builder.SetInsertPoint(MonotonicBB); 473 emitAtomicCmpXchg(CGF, E, IsWeak, Dest, Ptr, Val1, Val2, 474 Size, SuccessOrder, llvm::AtomicOrdering::Monotonic, Scope); 475 CGF.Builder.CreateBr(ContBB); 476 477 CGF.Builder.SetInsertPoint(AcquireBB); 478 emitAtomicCmpXchg(CGF, E, IsWeak, Dest, Ptr, Val1, Val2, Size, SuccessOrder, 479 llvm::AtomicOrdering::Acquire, Scope); 480 CGF.Builder.CreateBr(ContBB); 481 482 CGF.Builder.SetInsertPoint(SeqCstBB); 483 emitAtomicCmpXchg(CGF, E, IsWeak, Dest, Ptr, Val1, Val2, Size, SuccessOrder, 484 llvm::AtomicOrdering::SequentiallyConsistent, Scope); 485 CGF.Builder.CreateBr(ContBB); 486 487 CGF.Builder.SetInsertPoint(ContBB); 488 } 489 490 /// Duplicate the atomic min/max operation in conventional IR for the builtin 491 /// variants that return the new rather than the original value. 492 static llvm::Value *EmitPostAtomicMinMax(CGBuilderTy &Builder, 493 AtomicExpr::AtomicOp Op, 494 bool IsSigned, 495 llvm::Value *OldVal, 496 llvm::Value *RHS) { 497 llvm::CmpInst::Predicate Pred; 498 switch (Op) { 499 default: 500 llvm_unreachable("Unexpected min/max operation"); 501 case AtomicExpr::AO__atomic_max_fetch: 502 Pred = IsSigned ? llvm::CmpInst::ICMP_SGT : llvm::CmpInst::ICMP_UGT; 503 break; 504 case AtomicExpr::AO__atomic_min_fetch: 505 Pred = IsSigned ? llvm::CmpInst::ICMP_SLT : llvm::CmpInst::ICMP_ULT; 506 break; 507 } 508 llvm::Value *Cmp = Builder.CreateICmp(Pred, OldVal, RHS, "tst"); 509 return Builder.CreateSelect(Cmp, OldVal, RHS, "newval"); 510 } 511 512 static void EmitAtomicOp(CodeGenFunction &CGF, AtomicExpr *E, Address Dest, 513 Address Ptr, Address Val1, Address Val2, 514 llvm::Value *IsWeak, llvm::Value *FailureOrder, 515 uint64_t Size, llvm::AtomicOrdering Order, 516 llvm::SyncScope::ID Scope) { 517 llvm::AtomicRMWInst::BinOp Op = llvm::AtomicRMWInst::Add; 518 bool PostOpMinMax = false; 519 unsigned PostOp = 0; 520 521 switch (E->getOp()) { 522 case AtomicExpr::AO__c11_atomic_init: 523 case AtomicExpr::AO__opencl_atomic_init: 524 llvm_unreachable("Already handled!"); 525 526 case AtomicExpr::AO__c11_atomic_compare_exchange_strong: 527 case AtomicExpr::AO__opencl_atomic_compare_exchange_strong: 528 emitAtomicCmpXchgFailureSet(CGF, E, false, Dest, Ptr, Val1, Val2, 529 FailureOrder, Size, Order, Scope); 530 return; 531 case AtomicExpr::AO__c11_atomic_compare_exchange_weak: 532 case AtomicExpr::AO__opencl_atomic_compare_exchange_weak: 533 emitAtomicCmpXchgFailureSet(CGF, E, true, Dest, Ptr, Val1, Val2, 534 FailureOrder, Size, Order, Scope); 535 return; 536 case AtomicExpr::AO__atomic_compare_exchange: 537 case AtomicExpr::AO__atomic_compare_exchange_n: { 538 if (llvm::ConstantInt *IsWeakC = dyn_cast<llvm::ConstantInt>(IsWeak)) { 539 emitAtomicCmpXchgFailureSet(CGF, E, IsWeakC->getZExtValue(), Dest, Ptr, 540 Val1, Val2, FailureOrder, Size, Order, Scope); 541 } else { 542 // Create all the relevant BB's 543 llvm::BasicBlock *StrongBB = 544 CGF.createBasicBlock("cmpxchg.strong", CGF.CurFn); 545 llvm::BasicBlock *WeakBB = CGF.createBasicBlock("cmxchg.weak", CGF.CurFn); 546 llvm::BasicBlock *ContBB = 547 CGF.createBasicBlock("cmpxchg.continue", CGF.CurFn); 548 549 llvm::SwitchInst *SI = CGF.Builder.CreateSwitch(IsWeak, WeakBB); 550 SI->addCase(CGF.Builder.getInt1(false), StrongBB); 551 552 CGF.Builder.SetInsertPoint(StrongBB); 553 emitAtomicCmpXchgFailureSet(CGF, E, false, Dest, Ptr, Val1, Val2, 554 FailureOrder, Size, Order, Scope); 555 CGF.Builder.CreateBr(ContBB); 556 557 CGF.Builder.SetInsertPoint(WeakBB); 558 emitAtomicCmpXchgFailureSet(CGF, E, true, Dest, Ptr, Val1, Val2, 559 FailureOrder, Size, Order, Scope); 560 CGF.Builder.CreateBr(ContBB); 561 562 CGF.Builder.SetInsertPoint(ContBB); 563 } 564 return; 565 } 566 case AtomicExpr::AO__c11_atomic_load: 567 case AtomicExpr::AO__opencl_atomic_load: 568 case AtomicExpr::AO__atomic_load_n: 569 case AtomicExpr::AO__atomic_load: { 570 llvm::LoadInst *Load = CGF.Builder.CreateLoad(Ptr); 571 Load->setAtomic(Order, Scope); 572 Load->setVolatile(E->isVolatile()); 573 CGF.Builder.CreateStore(Load, Dest); 574 return; 575 } 576 577 case AtomicExpr::AO__c11_atomic_store: 578 case AtomicExpr::AO__opencl_atomic_store: 579 case AtomicExpr::AO__atomic_store: 580 case AtomicExpr::AO__atomic_store_n: { 581 llvm::Value *LoadVal1 = CGF.Builder.CreateLoad(Val1); 582 llvm::StoreInst *Store = CGF.Builder.CreateStore(LoadVal1, Ptr); 583 Store->setAtomic(Order, Scope); 584 Store->setVolatile(E->isVolatile()); 585 return; 586 } 587 588 case AtomicExpr::AO__c11_atomic_exchange: 589 case AtomicExpr::AO__opencl_atomic_exchange: 590 case AtomicExpr::AO__atomic_exchange_n: 591 case AtomicExpr::AO__atomic_exchange: 592 Op = llvm::AtomicRMWInst::Xchg; 593 break; 594 595 case AtomicExpr::AO__atomic_add_fetch: 596 PostOp = E->getValueType()->isFloatingType() ? llvm::Instruction::FAdd 597 : llvm::Instruction::Add; 598 LLVM_FALLTHROUGH; 599 case AtomicExpr::AO__c11_atomic_fetch_add: 600 case AtomicExpr::AO__opencl_atomic_fetch_add: 601 case AtomicExpr::AO__atomic_fetch_add: 602 Op = E->getValueType()->isFloatingType() ? llvm::AtomicRMWInst::FAdd 603 : llvm::AtomicRMWInst::Add; 604 break; 605 606 case AtomicExpr::AO__atomic_sub_fetch: 607 PostOp = E->getValueType()->isFloatingType() ? llvm::Instruction::FSub 608 : llvm::Instruction::Sub; 609 LLVM_FALLTHROUGH; 610 case AtomicExpr::AO__c11_atomic_fetch_sub: 611 case AtomicExpr::AO__opencl_atomic_fetch_sub: 612 case AtomicExpr::AO__atomic_fetch_sub: 613 Op = E->getValueType()->isFloatingType() ? llvm::AtomicRMWInst::FSub 614 : llvm::AtomicRMWInst::Sub; 615 break; 616 617 case AtomicExpr::AO__atomic_min_fetch: 618 PostOpMinMax = true; 619 LLVM_FALLTHROUGH; 620 case AtomicExpr::AO__c11_atomic_fetch_min: 621 case AtomicExpr::AO__opencl_atomic_fetch_min: 622 case AtomicExpr::AO__atomic_fetch_min: 623 Op = E->getValueType()->isSignedIntegerType() ? llvm::AtomicRMWInst::Min 624 : llvm::AtomicRMWInst::UMin; 625 break; 626 627 case AtomicExpr::AO__atomic_max_fetch: 628 PostOpMinMax = true; 629 LLVM_FALLTHROUGH; 630 case AtomicExpr::AO__c11_atomic_fetch_max: 631 case AtomicExpr::AO__opencl_atomic_fetch_max: 632 case AtomicExpr::AO__atomic_fetch_max: 633 Op = E->getValueType()->isSignedIntegerType() ? llvm::AtomicRMWInst::Max 634 : llvm::AtomicRMWInst::UMax; 635 break; 636 637 case AtomicExpr::AO__atomic_and_fetch: 638 PostOp = llvm::Instruction::And; 639 LLVM_FALLTHROUGH; 640 case AtomicExpr::AO__c11_atomic_fetch_and: 641 case AtomicExpr::AO__opencl_atomic_fetch_and: 642 case AtomicExpr::AO__atomic_fetch_and: 643 Op = llvm::AtomicRMWInst::And; 644 break; 645 646 case AtomicExpr::AO__atomic_or_fetch: 647 PostOp = llvm::Instruction::Or; 648 LLVM_FALLTHROUGH; 649 case AtomicExpr::AO__c11_atomic_fetch_or: 650 case AtomicExpr::AO__opencl_atomic_fetch_or: 651 case AtomicExpr::AO__atomic_fetch_or: 652 Op = llvm::AtomicRMWInst::Or; 653 break; 654 655 case AtomicExpr::AO__atomic_xor_fetch: 656 PostOp = llvm::Instruction::Xor; 657 LLVM_FALLTHROUGH; 658 case AtomicExpr::AO__c11_atomic_fetch_xor: 659 case AtomicExpr::AO__opencl_atomic_fetch_xor: 660 case AtomicExpr::AO__atomic_fetch_xor: 661 Op = llvm::AtomicRMWInst::Xor; 662 break; 663 664 case AtomicExpr::AO__atomic_nand_fetch: 665 PostOp = llvm::Instruction::And; // the NOT is special cased below 666 LLVM_FALLTHROUGH; 667 case AtomicExpr::AO__atomic_fetch_nand: 668 Op = llvm::AtomicRMWInst::Nand; 669 break; 670 } 671 672 llvm::Value *LoadVal1 = CGF.Builder.CreateLoad(Val1); 673 llvm::AtomicRMWInst *RMWI = 674 CGF.Builder.CreateAtomicRMW(Op, Ptr.getPointer(), LoadVal1, Order, Scope); 675 RMWI->setVolatile(E->isVolatile()); 676 677 // For __atomic_*_fetch operations, perform the operation again to 678 // determine the value which was written. 679 llvm::Value *Result = RMWI; 680 if (PostOpMinMax) 681 Result = EmitPostAtomicMinMax(CGF.Builder, E->getOp(), 682 E->getValueType()->isSignedIntegerType(), 683 RMWI, LoadVal1); 684 else if (PostOp) 685 Result = CGF.Builder.CreateBinOp((llvm::Instruction::BinaryOps)PostOp, RMWI, 686 LoadVal1); 687 if (E->getOp() == AtomicExpr::AO__atomic_nand_fetch) 688 Result = CGF.Builder.CreateNot(Result); 689 CGF.Builder.CreateStore(Result, Dest); 690 } 691 692 // This function emits any expression (scalar, complex, or aggregate) 693 // into a temporary alloca. 694 static Address 695 EmitValToTemp(CodeGenFunction &CGF, Expr *E) { 696 Address DeclPtr = CGF.CreateMemTemp(E->getType(), ".atomictmp"); 697 CGF.EmitAnyExprToMem(E, DeclPtr, E->getType().getQualifiers(), 698 /*Init*/ true); 699 return DeclPtr; 700 } 701 702 static void EmitAtomicOp(CodeGenFunction &CGF, AtomicExpr *Expr, Address Dest, 703 Address Ptr, Address Val1, Address Val2, 704 llvm::Value *IsWeak, llvm::Value *FailureOrder, 705 uint64_t Size, llvm::AtomicOrdering Order, 706 llvm::Value *Scope) { 707 auto ScopeModel = Expr->getScopeModel(); 708 709 // LLVM atomic instructions always have synch scope. If clang atomic 710 // expression has no scope operand, use default LLVM synch scope. 711 if (!ScopeModel) { 712 EmitAtomicOp(CGF, Expr, Dest, Ptr, Val1, Val2, IsWeak, FailureOrder, Size, 713 Order, CGF.CGM.getLLVMContext().getOrInsertSyncScopeID("")); 714 return; 715 } 716 717 // Handle constant scope. 718 if (auto SC = dyn_cast<llvm::ConstantInt>(Scope)) { 719 auto SCID = CGF.getTargetHooks().getLLVMSyncScopeID( 720 CGF.CGM.getLangOpts(), ScopeModel->map(SC->getZExtValue()), 721 Order, CGF.CGM.getLLVMContext()); 722 EmitAtomicOp(CGF, Expr, Dest, Ptr, Val1, Val2, IsWeak, FailureOrder, Size, 723 Order, SCID); 724 return; 725 } 726 727 // Handle non-constant scope. 728 auto &Builder = CGF.Builder; 729 auto Scopes = ScopeModel->getRuntimeValues(); 730 llvm::DenseMap<unsigned, llvm::BasicBlock *> BB; 731 for (auto S : Scopes) 732 BB[S] = CGF.createBasicBlock(getAsString(ScopeModel->map(S)), CGF.CurFn); 733 734 llvm::BasicBlock *ContBB = 735 CGF.createBasicBlock("atomic.scope.continue", CGF.CurFn); 736 737 auto *SC = Builder.CreateIntCast(Scope, Builder.getInt32Ty(), false); 738 // If unsupported synch scope is encountered at run time, assume a fallback 739 // synch scope value. 740 auto FallBack = ScopeModel->getFallBackValue(); 741 llvm::SwitchInst *SI = Builder.CreateSwitch(SC, BB[FallBack]); 742 for (auto S : Scopes) { 743 auto *B = BB[S]; 744 if (S != FallBack) 745 SI->addCase(Builder.getInt32(S), B); 746 747 Builder.SetInsertPoint(B); 748 EmitAtomicOp(CGF, Expr, Dest, Ptr, Val1, Val2, IsWeak, FailureOrder, Size, 749 Order, 750 CGF.getTargetHooks().getLLVMSyncScopeID(CGF.CGM.getLangOpts(), 751 ScopeModel->map(S), 752 Order, 753 CGF.getLLVMContext())); 754 Builder.CreateBr(ContBB); 755 } 756 757 Builder.SetInsertPoint(ContBB); 758 } 759 760 static void 761 AddDirectArgument(CodeGenFunction &CGF, CallArgList &Args, 762 bool UseOptimizedLibcall, llvm::Value *Val, QualType ValTy, 763 SourceLocation Loc, CharUnits SizeInChars) { 764 if (UseOptimizedLibcall) { 765 // Load value and pass it to the function directly. 766 CharUnits Align = CGF.getContext().getTypeAlignInChars(ValTy); 767 int64_t SizeInBits = CGF.getContext().toBits(SizeInChars); 768 ValTy = 769 CGF.getContext().getIntTypeForBitwidth(SizeInBits, /*Signed=*/false); 770 llvm::Type *IPtrTy = llvm::IntegerType::get(CGF.getLLVMContext(), 771 SizeInBits)->getPointerTo(); 772 Address Ptr = Address(CGF.Builder.CreateBitCast(Val, IPtrTy), Align); 773 Val = CGF.EmitLoadOfScalar(Ptr, false, 774 CGF.getContext().getPointerType(ValTy), 775 Loc); 776 // Coerce the value into an appropriately sized integer type. 777 Args.add(RValue::get(Val), ValTy); 778 } else { 779 // Non-optimized functions always take a reference. 780 Args.add(RValue::get(CGF.EmitCastToVoidPtr(Val)), 781 CGF.getContext().VoidPtrTy); 782 } 783 } 784 785 RValue CodeGenFunction::EmitAtomicExpr(AtomicExpr *E) { 786 QualType AtomicTy = E->getPtr()->getType()->getPointeeType(); 787 QualType MemTy = AtomicTy; 788 if (const AtomicType *AT = AtomicTy->getAs<AtomicType>()) 789 MemTy = AT->getValueType(); 790 llvm::Value *IsWeak = nullptr, *OrderFail = nullptr; 791 792 Address Val1 = Address::invalid(); 793 Address Val2 = Address::invalid(); 794 Address Dest = Address::invalid(); 795 Address Ptr = EmitPointerWithAlignment(E->getPtr()); 796 797 if (E->getOp() == AtomicExpr::AO__c11_atomic_init || 798 E->getOp() == AtomicExpr::AO__opencl_atomic_init) { 799 LValue lvalue = MakeAddrLValue(Ptr, AtomicTy); 800 EmitAtomicInit(E->getVal1(), lvalue); 801 return RValue::get(nullptr); 802 } 803 804 auto TInfo = getContext().getTypeInfoInChars(AtomicTy); 805 uint64_t Size = TInfo.Width.getQuantity(); 806 unsigned MaxInlineWidthInBits = getTarget().getMaxAtomicInlineWidth(); 807 808 bool Oversized = getContext().toBits(TInfo.Width) > MaxInlineWidthInBits; 809 bool Misaligned = (Ptr.getAlignment() % TInfo.Width) != 0; 810 bool UseLibcall = Misaligned | Oversized; 811 bool ShouldCastToIntPtrTy = true; 812 813 CharUnits MaxInlineWidth = 814 getContext().toCharUnitsFromBits(MaxInlineWidthInBits); 815 816 DiagnosticsEngine &Diags = CGM.getDiags(); 817 818 if (Misaligned) { 819 Diags.Report(E->getBeginLoc(), diag::warn_atomic_op_misaligned) 820 << (int)TInfo.Width.getQuantity() 821 << (int)Ptr.getAlignment().getQuantity(); 822 } 823 824 if (Oversized) { 825 Diags.Report(E->getBeginLoc(), diag::warn_atomic_op_oversized) 826 << (int)TInfo.Width.getQuantity() << (int)MaxInlineWidth.getQuantity(); 827 } 828 829 llvm::Value *Order = EmitScalarExpr(E->getOrder()); 830 llvm::Value *Scope = 831 E->getScopeModel() ? EmitScalarExpr(E->getScope()) : nullptr; 832 833 switch (E->getOp()) { 834 case AtomicExpr::AO__c11_atomic_init: 835 case AtomicExpr::AO__opencl_atomic_init: 836 llvm_unreachable("Already handled above with EmitAtomicInit!"); 837 838 case AtomicExpr::AO__c11_atomic_load: 839 case AtomicExpr::AO__opencl_atomic_load: 840 case AtomicExpr::AO__atomic_load_n: 841 break; 842 843 case AtomicExpr::AO__atomic_load: 844 Dest = EmitPointerWithAlignment(E->getVal1()); 845 break; 846 847 case AtomicExpr::AO__atomic_store: 848 Val1 = EmitPointerWithAlignment(E->getVal1()); 849 break; 850 851 case AtomicExpr::AO__atomic_exchange: 852 Val1 = EmitPointerWithAlignment(E->getVal1()); 853 Dest = EmitPointerWithAlignment(E->getVal2()); 854 break; 855 856 case AtomicExpr::AO__c11_atomic_compare_exchange_strong: 857 case AtomicExpr::AO__c11_atomic_compare_exchange_weak: 858 case AtomicExpr::AO__opencl_atomic_compare_exchange_strong: 859 case AtomicExpr::AO__opencl_atomic_compare_exchange_weak: 860 case AtomicExpr::AO__atomic_compare_exchange_n: 861 case AtomicExpr::AO__atomic_compare_exchange: 862 Val1 = EmitPointerWithAlignment(E->getVal1()); 863 if (E->getOp() == AtomicExpr::AO__atomic_compare_exchange) 864 Val2 = EmitPointerWithAlignment(E->getVal2()); 865 else 866 Val2 = EmitValToTemp(*this, E->getVal2()); 867 OrderFail = EmitScalarExpr(E->getOrderFail()); 868 if (E->getOp() == AtomicExpr::AO__atomic_compare_exchange_n || 869 E->getOp() == AtomicExpr::AO__atomic_compare_exchange) 870 IsWeak = EmitScalarExpr(E->getWeak()); 871 break; 872 873 case AtomicExpr::AO__c11_atomic_fetch_add: 874 case AtomicExpr::AO__c11_atomic_fetch_sub: 875 case AtomicExpr::AO__opencl_atomic_fetch_add: 876 case AtomicExpr::AO__opencl_atomic_fetch_sub: 877 if (MemTy->isPointerType()) { 878 // For pointer arithmetic, we're required to do a bit of math: 879 // adding 1 to an int* is not the same as adding 1 to a uintptr_t. 880 // ... but only for the C11 builtins. The GNU builtins expect the 881 // user to multiply by sizeof(T). 882 QualType Val1Ty = E->getVal1()->getType(); 883 llvm::Value *Val1Scalar = EmitScalarExpr(E->getVal1()); 884 CharUnits PointeeIncAmt = 885 getContext().getTypeSizeInChars(MemTy->getPointeeType()); 886 Val1Scalar = Builder.CreateMul(Val1Scalar, CGM.getSize(PointeeIncAmt)); 887 auto Temp = CreateMemTemp(Val1Ty, ".atomictmp"); 888 Val1 = Temp; 889 EmitStoreOfScalar(Val1Scalar, MakeAddrLValue(Temp, Val1Ty)); 890 break; 891 } 892 LLVM_FALLTHROUGH; 893 case AtomicExpr::AO__atomic_fetch_add: 894 case AtomicExpr::AO__atomic_fetch_sub: 895 case AtomicExpr::AO__atomic_add_fetch: 896 case AtomicExpr::AO__atomic_sub_fetch: 897 ShouldCastToIntPtrTy = !MemTy->isFloatingType(); 898 LLVM_FALLTHROUGH; 899 900 case AtomicExpr::AO__c11_atomic_store: 901 case AtomicExpr::AO__c11_atomic_exchange: 902 case AtomicExpr::AO__opencl_atomic_store: 903 case AtomicExpr::AO__opencl_atomic_exchange: 904 case AtomicExpr::AO__atomic_store_n: 905 case AtomicExpr::AO__atomic_exchange_n: 906 case AtomicExpr::AO__c11_atomic_fetch_and: 907 case AtomicExpr::AO__c11_atomic_fetch_or: 908 case AtomicExpr::AO__c11_atomic_fetch_xor: 909 case AtomicExpr::AO__c11_atomic_fetch_max: 910 case AtomicExpr::AO__c11_atomic_fetch_min: 911 case AtomicExpr::AO__opencl_atomic_fetch_and: 912 case AtomicExpr::AO__opencl_atomic_fetch_or: 913 case AtomicExpr::AO__opencl_atomic_fetch_xor: 914 case AtomicExpr::AO__opencl_atomic_fetch_min: 915 case AtomicExpr::AO__opencl_atomic_fetch_max: 916 case AtomicExpr::AO__atomic_fetch_and: 917 case AtomicExpr::AO__atomic_fetch_or: 918 case AtomicExpr::AO__atomic_fetch_xor: 919 case AtomicExpr::AO__atomic_fetch_nand: 920 case AtomicExpr::AO__atomic_and_fetch: 921 case AtomicExpr::AO__atomic_or_fetch: 922 case AtomicExpr::AO__atomic_xor_fetch: 923 case AtomicExpr::AO__atomic_nand_fetch: 924 case AtomicExpr::AO__atomic_max_fetch: 925 case AtomicExpr::AO__atomic_min_fetch: 926 case AtomicExpr::AO__atomic_fetch_max: 927 case AtomicExpr::AO__atomic_fetch_min: 928 Val1 = EmitValToTemp(*this, E->getVal1()); 929 break; 930 } 931 932 QualType RValTy = E->getType().getUnqualifiedType(); 933 934 // The inlined atomics only function on iN types, where N is a power of 2. We 935 // need to make sure (via temporaries if necessary) that all incoming values 936 // are compatible. 937 LValue AtomicVal = MakeAddrLValue(Ptr, AtomicTy); 938 AtomicInfo Atomics(*this, AtomicVal); 939 940 if (ShouldCastToIntPtrTy) { 941 Ptr = Atomics.emitCastToAtomicIntPointer(Ptr); 942 if (Val1.isValid()) 943 Val1 = Atomics.convertToAtomicIntPointer(Val1); 944 if (Val2.isValid()) 945 Val2 = Atomics.convertToAtomicIntPointer(Val2); 946 } 947 if (Dest.isValid()) { 948 if (ShouldCastToIntPtrTy) 949 Dest = Atomics.emitCastToAtomicIntPointer(Dest); 950 } else if (E->isCmpXChg()) 951 Dest = CreateMemTemp(RValTy, "cmpxchg.bool"); 952 else if (!RValTy->isVoidType()) { 953 Dest = Atomics.CreateTempAlloca(); 954 if (ShouldCastToIntPtrTy) 955 Dest = Atomics.emitCastToAtomicIntPointer(Dest); 956 } 957 958 // Use a library call. See: http://gcc.gnu.org/wiki/Atomic/GCCMM/LIbrary . 959 if (UseLibcall) { 960 bool UseOptimizedLibcall = false; 961 switch (E->getOp()) { 962 case AtomicExpr::AO__c11_atomic_init: 963 case AtomicExpr::AO__opencl_atomic_init: 964 llvm_unreachable("Already handled above with EmitAtomicInit!"); 965 966 case AtomicExpr::AO__c11_atomic_fetch_add: 967 case AtomicExpr::AO__opencl_atomic_fetch_add: 968 case AtomicExpr::AO__atomic_fetch_add: 969 case AtomicExpr::AO__c11_atomic_fetch_and: 970 case AtomicExpr::AO__opencl_atomic_fetch_and: 971 case AtomicExpr::AO__atomic_fetch_and: 972 case AtomicExpr::AO__c11_atomic_fetch_or: 973 case AtomicExpr::AO__opencl_atomic_fetch_or: 974 case AtomicExpr::AO__atomic_fetch_or: 975 case AtomicExpr::AO__atomic_fetch_nand: 976 case AtomicExpr::AO__c11_atomic_fetch_sub: 977 case AtomicExpr::AO__opencl_atomic_fetch_sub: 978 case AtomicExpr::AO__atomic_fetch_sub: 979 case AtomicExpr::AO__c11_atomic_fetch_xor: 980 case AtomicExpr::AO__opencl_atomic_fetch_xor: 981 case AtomicExpr::AO__opencl_atomic_fetch_min: 982 case AtomicExpr::AO__opencl_atomic_fetch_max: 983 case AtomicExpr::AO__atomic_fetch_xor: 984 case AtomicExpr::AO__c11_atomic_fetch_max: 985 case AtomicExpr::AO__c11_atomic_fetch_min: 986 case AtomicExpr::AO__atomic_add_fetch: 987 case AtomicExpr::AO__atomic_and_fetch: 988 case AtomicExpr::AO__atomic_nand_fetch: 989 case AtomicExpr::AO__atomic_or_fetch: 990 case AtomicExpr::AO__atomic_sub_fetch: 991 case AtomicExpr::AO__atomic_xor_fetch: 992 case AtomicExpr::AO__atomic_fetch_max: 993 case AtomicExpr::AO__atomic_fetch_min: 994 case AtomicExpr::AO__atomic_max_fetch: 995 case AtomicExpr::AO__atomic_min_fetch: 996 // For these, only library calls for certain sizes exist. 997 UseOptimizedLibcall = true; 998 break; 999 1000 case AtomicExpr::AO__atomic_load: 1001 case AtomicExpr::AO__atomic_store: 1002 case AtomicExpr::AO__atomic_exchange: 1003 case AtomicExpr::AO__atomic_compare_exchange: 1004 // Use the generic version if we don't know that the operand will be 1005 // suitably aligned for the optimized version. 1006 if (Misaligned) 1007 break; 1008 LLVM_FALLTHROUGH; 1009 case AtomicExpr::AO__c11_atomic_load: 1010 case AtomicExpr::AO__c11_atomic_store: 1011 case AtomicExpr::AO__c11_atomic_exchange: 1012 case AtomicExpr::AO__c11_atomic_compare_exchange_weak: 1013 case AtomicExpr::AO__c11_atomic_compare_exchange_strong: 1014 case AtomicExpr::AO__opencl_atomic_load: 1015 case AtomicExpr::AO__opencl_atomic_store: 1016 case AtomicExpr::AO__opencl_atomic_exchange: 1017 case AtomicExpr::AO__opencl_atomic_compare_exchange_weak: 1018 case AtomicExpr::AO__opencl_atomic_compare_exchange_strong: 1019 case AtomicExpr::AO__atomic_load_n: 1020 case AtomicExpr::AO__atomic_store_n: 1021 case AtomicExpr::AO__atomic_exchange_n: 1022 case AtomicExpr::AO__atomic_compare_exchange_n: 1023 // Only use optimized library calls for sizes for which they exist. 1024 // FIXME: Size == 16 optimized library functions exist too. 1025 if (Size == 1 || Size == 2 || Size == 4 || Size == 8) 1026 UseOptimizedLibcall = true; 1027 break; 1028 } 1029 1030 CallArgList Args; 1031 if (!UseOptimizedLibcall) { 1032 // For non-optimized library calls, the size is the first parameter 1033 Args.add(RValue::get(llvm::ConstantInt::get(SizeTy, Size)), 1034 getContext().getSizeType()); 1035 } 1036 // Atomic address is the first or second parameter 1037 // The OpenCL atomic library functions only accept pointer arguments to 1038 // generic address space. 1039 auto CastToGenericAddrSpace = [&](llvm::Value *V, QualType PT) { 1040 if (!E->isOpenCL()) 1041 return V; 1042 auto AS = PT->castAs<PointerType>()->getPointeeType().getAddressSpace(); 1043 if (AS == LangAS::opencl_generic) 1044 return V; 1045 auto DestAS = getContext().getTargetAddressSpace(LangAS::opencl_generic); 1046 auto T = V->getType(); 1047 auto *DestType = T->getPointerElementType()->getPointerTo(DestAS); 1048 1049 return getTargetHooks().performAddrSpaceCast( 1050 *this, V, AS, LangAS::opencl_generic, DestType, false); 1051 }; 1052 1053 Args.add(RValue::get(CastToGenericAddrSpace( 1054 EmitCastToVoidPtr(Ptr.getPointer()), E->getPtr()->getType())), 1055 getContext().VoidPtrTy); 1056 1057 std::string LibCallName; 1058 QualType LoweredMemTy = 1059 MemTy->isPointerType() ? getContext().getIntPtrType() : MemTy; 1060 QualType RetTy; 1061 bool HaveRetTy = false; 1062 llvm::Instruction::BinaryOps PostOp = (llvm::Instruction::BinaryOps)0; 1063 bool PostOpMinMax = false; 1064 switch (E->getOp()) { 1065 case AtomicExpr::AO__c11_atomic_init: 1066 case AtomicExpr::AO__opencl_atomic_init: 1067 llvm_unreachable("Already handled!"); 1068 1069 // There is only one libcall for compare an exchange, because there is no 1070 // optimisation benefit possible from a libcall version of a weak compare 1071 // and exchange. 1072 // bool __atomic_compare_exchange(size_t size, void *mem, void *expected, 1073 // void *desired, int success, int failure) 1074 // bool __atomic_compare_exchange_N(T *mem, T *expected, T desired, 1075 // int success, int failure) 1076 case AtomicExpr::AO__c11_atomic_compare_exchange_weak: 1077 case AtomicExpr::AO__c11_atomic_compare_exchange_strong: 1078 case AtomicExpr::AO__opencl_atomic_compare_exchange_weak: 1079 case AtomicExpr::AO__opencl_atomic_compare_exchange_strong: 1080 case AtomicExpr::AO__atomic_compare_exchange: 1081 case AtomicExpr::AO__atomic_compare_exchange_n: 1082 LibCallName = "__atomic_compare_exchange"; 1083 RetTy = getContext().BoolTy; 1084 HaveRetTy = true; 1085 Args.add( 1086 RValue::get(CastToGenericAddrSpace( 1087 EmitCastToVoidPtr(Val1.getPointer()), E->getVal1()->getType())), 1088 getContext().VoidPtrTy); 1089 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val2.getPointer(), 1090 MemTy, E->getExprLoc(), TInfo.Width); 1091 Args.add(RValue::get(Order), getContext().IntTy); 1092 Order = OrderFail; 1093 break; 1094 // void __atomic_exchange(size_t size, void *mem, void *val, void *return, 1095 // int order) 1096 // T __atomic_exchange_N(T *mem, T val, int order) 1097 case AtomicExpr::AO__c11_atomic_exchange: 1098 case AtomicExpr::AO__opencl_atomic_exchange: 1099 case AtomicExpr::AO__atomic_exchange_n: 1100 case AtomicExpr::AO__atomic_exchange: 1101 LibCallName = "__atomic_exchange"; 1102 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1103 MemTy, E->getExprLoc(), TInfo.Width); 1104 break; 1105 // void __atomic_store(size_t size, void *mem, void *val, int order) 1106 // void __atomic_store_N(T *mem, T val, int order) 1107 case AtomicExpr::AO__c11_atomic_store: 1108 case AtomicExpr::AO__opencl_atomic_store: 1109 case AtomicExpr::AO__atomic_store: 1110 case AtomicExpr::AO__atomic_store_n: 1111 LibCallName = "__atomic_store"; 1112 RetTy = getContext().VoidTy; 1113 HaveRetTy = true; 1114 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1115 MemTy, E->getExprLoc(), TInfo.Width); 1116 break; 1117 // void __atomic_load(size_t size, void *mem, void *return, int order) 1118 // T __atomic_load_N(T *mem, int order) 1119 case AtomicExpr::AO__c11_atomic_load: 1120 case AtomicExpr::AO__opencl_atomic_load: 1121 case AtomicExpr::AO__atomic_load: 1122 case AtomicExpr::AO__atomic_load_n: 1123 LibCallName = "__atomic_load"; 1124 break; 1125 // T __atomic_add_fetch_N(T *mem, T val, int order) 1126 // T __atomic_fetch_add_N(T *mem, T val, int order) 1127 case AtomicExpr::AO__atomic_add_fetch: 1128 PostOp = llvm::Instruction::Add; 1129 LLVM_FALLTHROUGH; 1130 case AtomicExpr::AO__c11_atomic_fetch_add: 1131 case AtomicExpr::AO__opencl_atomic_fetch_add: 1132 case AtomicExpr::AO__atomic_fetch_add: 1133 LibCallName = "__atomic_fetch_add"; 1134 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1135 LoweredMemTy, E->getExprLoc(), TInfo.Width); 1136 break; 1137 // T __atomic_and_fetch_N(T *mem, T val, int order) 1138 // T __atomic_fetch_and_N(T *mem, T val, int order) 1139 case AtomicExpr::AO__atomic_and_fetch: 1140 PostOp = llvm::Instruction::And; 1141 LLVM_FALLTHROUGH; 1142 case AtomicExpr::AO__c11_atomic_fetch_and: 1143 case AtomicExpr::AO__opencl_atomic_fetch_and: 1144 case AtomicExpr::AO__atomic_fetch_and: 1145 LibCallName = "__atomic_fetch_and"; 1146 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1147 MemTy, E->getExprLoc(), TInfo.Width); 1148 break; 1149 // T __atomic_or_fetch_N(T *mem, T val, int order) 1150 // T __atomic_fetch_or_N(T *mem, T val, int order) 1151 case AtomicExpr::AO__atomic_or_fetch: 1152 PostOp = llvm::Instruction::Or; 1153 LLVM_FALLTHROUGH; 1154 case AtomicExpr::AO__c11_atomic_fetch_or: 1155 case AtomicExpr::AO__opencl_atomic_fetch_or: 1156 case AtomicExpr::AO__atomic_fetch_or: 1157 LibCallName = "__atomic_fetch_or"; 1158 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1159 MemTy, E->getExprLoc(), TInfo.Width); 1160 break; 1161 // T __atomic_sub_fetch_N(T *mem, T val, int order) 1162 // T __atomic_fetch_sub_N(T *mem, T val, int order) 1163 case AtomicExpr::AO__atomic_sub_fetch: 1164 PostOp = llvm::Instruction::Sub; 1165 LLVM_FALLTHROUGH; 1166 case AtomicExpr::AO__c11_atomic_fetch_sub: 1167 case AtomicExpr::AO__opencl_atomic_fetch_sub: 1168 case AtomicExpr::AO__atomic_fetch_sub: 1169 LibCallName = "__atomic_fetch_sub"; 1170 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1171 LoweredMemTy, E->getExprLoc(), TInfo.Width); 1172 break; 1173 // T __atomic_xor_fetch_N(T *mem, T val, int order) 1174 // T __atomic_fetch_xor_N(T *mem, T val, int order) 1175 case AtomicExpr::AO__atomic_xor_fetch: 1176 PostOp = llvm::Instruction::Xor; 1177 LLVM_FALLTHROUGH; 1178 case AtomicExpr::AO__c11_atomic_fetch_xor: 1179 case AtomicExpr::AO__opencl_atomic_fetch_xor: 1180 case AtomicExpr::AO__atomic_fetch_xor: 1181 LibCallName = "__atomic_fetch_xor"; 1182 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1183 MemTy, E->getExprLoc(), TInfo.Width); 1184 break; 1185 case AtomicExpr::AO__atomic_min_fetch: 1186 PostOpMinMax = true; 1187 LLVM_FALLTHROUGH; 1188 case AtomicExpr::AO__c11_atomic_fetch_min: 1189 case AtomicExpr::AO__atomic_fetch_min: 1190 case AtomicExpr::AO__opencl_atomic_fetch_min: 1191 LibCallName = E->getValueType()->isSignedIntegerType() 1192 ? "__atomic_fetch_min" 1193 : "__atomic_fetch_umin"; 1194 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1195 LoweredMemTy, E->getExprLoc(), TInfo.Width); 1196 break; 1197 case AtomicExpr::AO__atomic_max_fetch: 1198 PostOpMinMax = true; 1199 LLVM_FALLTHROUGH; 1200 case AtomicExpr::AO__c11_atomic_fetch_max: 1201 case AtomicExpr::AO__atomic_fetch_max: 1202 case AtomicExpr::AO__opencl_atomic_fetch_max: 1203 LibCallName = E->getValueType()->isSignedIntegerType() 1204 ? "__atomic_fetch_max" 1205 : "__atomic_fetch_umax"; 1206 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1207 LoweredMemTy, E->getExprLoc(), TInfo.Width); 1208 break; 1209 // T __atomic_nand_fetch_N(T *mem, T val, int order) 1210 // T __atomic_fetch_nand_N(T *mem, T val, int order) 1211 case AtomicExpr::AO__atomic_nand_fetch: 1212 PostOp = llvm::Instruction::And; // the NOT is special cased below 1213 LLVM_FALLTHROUGH; 1214 case AtomicExpr::AO__atomic_fetch_nand: 1215 LibCallName = "__atomic_fetch_nand"; 1216 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1217 MemTy, E->getExprLoc(), TInfo.Width); 1218 break; 1219 } 1220 1221 if (E->isOpenCL()) { 1222 LibCallName = std::string("__opencl") + 1223 StringRef(LibCallName).drop_front(1).str(); 1224 1225 } 1226 // Optimized functions have the size in their name. 1227 if (UseOptimizedLibcall) 1228 LibCallName += "_" + llvm::utostr(Size); 1229 // By default, assume we return a value of the atomic type. 1230 if (!HaveRetTy) { 1231 if (UseOptimizedLibcall) { 1232 // Value is returned directly. 1233 // The function returns an appropriately sized integer type. 1234 RetTy = getContext().getIntTypeForBitwidth( 1235 getContext().toBits(TInfo.Width), /*Signed=*/false); 1236 } else { 1237 // Value is returned through parameter before the order. 1238 RetTy = getContext().VoidTy; 1239 Args.add(RValue::get(EmitCastToVoidPtr(Dest.getPointer())), 1240 getContext().VoidPtrTy); 1241 } 1242 } 1243 // order is always the last parameter 1244 Args.add(RValue::get(Order), 1245 getContext().IntTy); 1246 if (E->isOpenCL()) 1247 Args.add(RValue::get(Scope), getContext().IntTy); 1248 1249 // PostOp is only needed for the atomic_*_fetch operations, and 1250 // thus is only needed for and implemented in the 1251 // UseOptimizedLibcall codepath. 1252 assert(UseOptimizedLibcall || (!PostOp && !PostOpMinMax)); 1253 1254 RValue Res = emitAtomicLibcall(*this, LibCallName, RetTy, Args); 1255 // The value is returned directly from the libcall. 1256 if (E->isCmpXChg()) 1257 return Res; 1258 1259 // The value is returned directly for optimized libcalls but the expr 1260 // provided an out-param. 1261 if (UseOptimizedLibcall && Res.getScalarVal()) { 1262 llvm::Value *ResVal = Res.getScalarVal(); 1263 if (PostOpMinMax) { 1264 llvm::Value *LoadVal1 = Args[1].getRValue(*this).getScalarVal(); 1265 ResVal = EmitPostAtomicMinMax(Builder, E->getOp(), 1266 E->getValueType()->isSignedIntegerType(), 1267 ResVal, LoadVal1); 1268 } else if (PostOp) { 1269 llvm::Value *LoadVal1 = Args[1].getRValue(*this).getScalarVal(); 1270 ResVal = Builder.CreateBinOp(PostOp, ResVal, LoadVal1); 1271 } 1272 if (E->getOp() == AtomicExpr::AO__atomic_nand_fetch) 1273 ResVal = Builder.CreateNot(ResVal); 1274 1275 Builder.CreateStore( 1276 ResVal, 1277 Builder.CreateBitCast(Dest, ResVal->getType()->getPointerTo())); 1278 } 1279 1280 if (RValTy->isVoidType()) 1281 return RValue::get(nullptr); 1282 1283 return convertTempToRValue( 1284 Builder.CreateBitCast(Dest, ConvertTypeForMem(RValTy)->getPointerTo()), 1285 RValTy, E->getExprLoc()); 1286 } 1287 1288 bool IsStore = E->getOp() == AtomicExpr::AO__c11_atomic_store || 1289 E->getOp() == AtomicExpr::AO__opencl_atomic_store || 1290 E->getOp() == AtomicExpr::AO__atomic_store || 1291 E->getOp() == AtomicExpr::AO__atomic_store_n; 1292 bool IsLoad = E->getOp() == AtomicExpr::AO__c11_atomic_load || 1293 E->getOp() == AtomicExpr::AO__opencl_atomic_load || 1294 E->getOp() == AtomicExpr::AO__atomic_load || 1295 E->getOp() == AtomicExpr::AO__atomic_load_n; 1296 1297 if (isa<llvm::ConstantInt>(Order)) { 1298 auto ord = cast<llvm::ConstantInt>(Order)->getZExtValue(); 1299 // We should not ever get to a case where the ordering isn't a valid C ABI 1300 // value, but it's hard to enforce that in general. 1301 if (llvm::isValidAtomicOrderingCABI(ord)) 1302 switch ((llvm::AtomicOrderingCABI)ord) { 1303 case llvm::AtomicOrderingCABI::relaxed: 1304 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1305 llvm::AtomicOrdering::Monotonic, Scope); 1306 break; 1307 case llvm::AtomicOrderingCABI::consume: 1308 case llvm::AtomicOrderingCABI::acquire: 1309 if (IsStore) 1310 break; // Avoid crashing on code with undefined behavior 1311 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1312 llvm::AtomicOrdering::Acquire, Scope); 1313 break; 1314 case llvm::AtomicOrderingCABI::release: 1315 if (IsLoad) 1316 break; // Avoid crashing on code with undefined behavior 1317 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1318 llvm::AtomicOrdering::Release, Scope); 1319 break; 1320 case llvm::AtomicOrderingCABI::acq_rel: 1321 if (IsLoad || IsStore) 1322 break; // Avoid crashing on code with undefined behavior 1323 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1324 llvm::AtomicOrdering::AcquireRelease, Scope); 1325 break; 1326 case llvm::AtomicOrderingCABI::seq_cst: 1327 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1328 llvm::AtomicOrdering::SequentiallyConsistent, Scope); 1329 break; 1330 } 1331 if (RValTy->isVoidType()) 1332 return RValue::get(nullptr); 1333 1334 return convertTempToRValue( 1335 Builder.CreateBitCast(Dest, ConvertTypeForMem(RValTy)->getPointerTo( 1336 Dest.getAddressSpace())), 1337 RValTy, E->getExprLoc()); 1338 } 1339 1340 // Long case, when Order isn't obviously constant. 1341 1342 // Create all the relevant BB's 1343 llvm::BasicBlock *MonotonicBB = nullptr, *AcquireBB = nullptr, 1344 *ReleaseBB = nullptr, *AcqRelBB = nullptr, 1345 *SeqCstBB = nullptr; 1346 MonotonicBB = createBasicBlock("monotonic", CurFn); 1347 if (!IsStore) 1348 AcquireBB = createBasicBlock("acquire", CurFn); 1349 if (!IsLoad) 1350 ReleaseBB = createBasicBlock("release", CurFn); 1351 if (!IsLoad && !IsStore) 1352 AcqRelBB = createBasicBlock("acqrel", CurFn); 1353 SeqCstBB = createBasicBlock("seqcst", CurFn); 1354 llvm::BasicBlock *ContBB = createBasicBlock("atomic.continue", CurFn); 1355 1356 // Create the switch for the split 1357 // MonotonicBB is arbitrarily chosen as the default case; in practice, this 1358 // doesn't matter unless someone is crazy enough to use something that 1359 // doesn't fold to a constant for the ordering. 1360 Order = Builder.CreateIntCast(Order, Builder.getInt32Ty(), false); 1361 llvm::SwitchInst *SI = Builder.CreateSwitch(Order, MonotonicBB); 1362 1363 // Emit all the different atomics 1364 Builder.SetInsertPoint(MonotonicBB); 1365 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1366 llvm::AtomicOrdering::Monotonic, Scope); 1367 Builder.CreateBr(ContBB); 1368 if (!IsStore) { 1369 Builder.SetInsertPoint(AcquireBB); 1370 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1371 llvm::AtomicOrdering::Acquire, Scope); 1372 Builder.CreateBr(ContBB); 1373 SI->addCase(Builder.getInt32((int)llvm::AtomicOrderingCABI::consume), 1374 AcquireBB); 1375 SI->addCase(Builder.getInt32((int)llvm::AtomicOrderingCABI::acquire), 1376 AcquireBB); 1377 } 1378 if (!IsLoad) { 1379 Builder.SetInsertPoint(ReleaseBB); 1380 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1381 llvm::AtomicOrdering::Release, Scope); 1382 Builder.CreateBr(ContBB); 1383 SI->addCase(Builder.getInt32((int)llvm::AtomicOrderingCABI::release), 1384 ReleaseBB); 1385 } 1386 if (!IsLoad && !IsStore) { 1387 Builder.SetInsertPoint(AcqRelBB); 1388 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1389 llvm::AtomicOrdering::AcquireRelease, Scope); 1390 Builder.CreateBr(ContBB); 1391 SI->addCase(Builder.getInt32((int)llvm::AtomicOrderingCABI::acq_rel), 1392 AcqRelBB); 1393 } 1394 Builder.SetInsertPoint(SeqCstBB); 1395 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1396 llvm::AtomicOrdering::SequentiallyConsistent, Scope); 1397 Builder.CreateBr(ContBB); 1398 SI->addCase(Builder.getInt32((int)llvm::AtomicOrderingCABI::seq_cst), 1399 SeqCstBB); 1400 1401 // Cleanup and return 1402 Builder.SetInsertPoint(ContBB); 1403 if (RValTy->isVoidType()) 1404 return RValue::get(nullptr); 1405 1406 assert(Atomics.getValueSizeInBits() <= Atomics.getAtomicSizeInBits()); 1407 return convertTempToRValue( 1408 Builder.CreateBitCast(Dest, ConvertTypeForMem(RValTy)->getPointerTo( 1409 Dest.getAddressSpace())), 1410 RValTy, E->getExprLoc()); 1411 } 1412 1413 Address AtomicInfo::emitCastToAtomicIntPointer(Address addr) const { 1414 unsigned addrspace = 1415 cast<llvm::PointerType>(addr.getPointer()->getType())->getAddressSpace(); 1416 llvm::IntegerType *ty = 1417 llvm::IntegerType::get(CGF.getLLVMContext(), AtomicSizeInBits); 1418 return CGF.Builder.CreateBitCast(addr, ty->getPointerTo(addrspace)); 1419 } 1420 1421 Address AtomicInfo::convertToAtomicIntPointer(Address Addr) const { 1422 llvm::Type *Ty = Addr.getElementType(); 1423 uint64_t SourceSizeInBits = CGF.CGM.getDataLayout().getTypeSizeInBits(Ty); 1424 if (SourceSizeInBits != AtomicSizeInBits) { 1425 Address Tmp = CreateTempAlloca(); 1426 CGF.Builder.CreateMemCpy(Tmp, Addr, 1427 std::min(AtomicSizeInBits, SourceSizeInBits) / 8); 1428 Addr = Tmp; 1429 } 1430 1431 return emitCastToAtomicIntPointer(Addr); 1432 } 1433 1434 RValue AtomicInfo::convertAtomicTempToRValue(Address addr, 1435 AggValueSlot resultSlot, 1436 SourceLocation loc, 1437 bool asValue) const { 1438 if (LVal.isSimple()) { 1439 if (EvaluationKind == TEK_Aggregate) 1440 return resultSlot.asRValue(); 1441 1442 // Drill into the padding structure if we have one. 1443 if (hasPadding()) 1444 addr = CGF.Builder.CreateStructGEP(addr, 0); 1445 1446 // Otherwise, just convert the temporary to an r-value using the 1447 // normal conversion routine. 1448 return CGF.convertTempToRValue(addr, getValueType(), loc); 1449 } 1450 if (!asValue) 1451 // Get RValue from temp memory as atomic for non-simple lvalues 1452 return RValue::get(CGF.Builder.CreateLoad(addr)); 1453 if (LVal.isBitField()) 1454 return CGF.EmitLoadOfBitfieldLValue( 1455 LValue::MakeBitfield(addr, LVal.getBitFieldInfo(), LVal.getType(), 1456 LVal.getBaseInfo(), TBAAAccessInfo()), loc); 1457 if (LVal.isVectorElt()) 1458 return CGF.EmitLoadOfLValue( 1459 LValue::MakeVectorElt(addr, LVal.getVectorIdx(), LVal.getType(), 1460 LVal.getBaseInfo(), TBAAAccessInfo()), loc); 1461 assert(LVal.isExtVectorElt()); 1462 return CGF.EmitLoadOfExtVectorElementLValue(LValue::MakeExtVectorElt( 1463 addr, LVal.getExtVectorElts(), LVal.getType(), 1464 LVal.getBaseInfo(), TBAAAccessInfo())); 1465 } 1466 1467 RValue AtomicInfo::ConvertIntToValueOrAtomic(llvm::Value *IntVal, 1468 AggValueSlot ResultSlot, 1469 SourceLocation Loc, 1470 bool AsValue) const { 1471 // Try not to in some easy cases. 1472 assert(IntVal->getType()->isIntegerTy() && "Expected integer value"); 1473 if (getEvaluationKind() == TEK_Scalar && 1474 (((!LVal.isBitField() || 1475 LVal.getBitFieldInfo().Size == ValueSizeInBits) && 1476 !hasPadding()) || 1477 !AsValue)) { 1478 auto *ValTy = AsValue 1479 ? CGF.ConvertTypeForMem(ValueTy) 1480 : getAtomicAddress().getType()->getPointerElementType(); 1481 if (ValTy->isIntegerTy()) { 1482 assert(IntVal->getType() == ValTy && "Different integer types."); 1483 return RValue::get(CGF.EmitFromMemory(IntVal, ValueTy)); 1484 } else if (ValTy->isPointerTy()) 1485 return RValue::get(CGF.Builder.CreateIntToPtr(IntVal, ValTy)); 1486 else if (llvm::CastInst::isBitCastable(IntVal->getType(), ValTy)) 1487 return RValue::get(CGF.Builder.CreateBitCast(IntVal, ValTy)); 1488 } 1489 1490 // Create a temporary. This needs to be big enough to hold the 1491 // atomic integer. 1492 Address Temp = Address::invalid(); 1493 bool TempIsVolatile = false; 1494 if (AsValue && getEvaluationKind() == TEK_Aggregate) { 1495 assert(!ResultSlot.isIgnored()); 1496 Temp = ResultSlot.getAddress(); 1497 TempIsVolatile = ResultSlot.isVolatile(); 1498 } else { 1499 Temp = CreateTempAlloca(); 1500 } 1501 1502 // Slam the integer into the temporary. 1503 Address CastTemp = emitCastToAtomicIntPointer(Temp); 1504 CGF.Builder.CreateStore(IntVal, CastTemp) 1505 ->setVolatile(TempIsVolatile); 1506 1507 return convertAtomicTempToRValue(Temp, ResultSlot, Loc, AsValue); 1508 } 1509 1510 void AtomicInfo::EmitAtomicLoadLibcall(llvm::Value *AddForLoaded, 1511 llvm::AtomicOrdering AO, bool) { 1512 // void __atomic_load(size_t size, void *mem, void *return, int order); 1513 CallArgList Args; 1514 Args.add(RValue::get(getAtomicSizeValue()), CGF.getContext().getSizeType()); 1515 Args.add(RValue::get(CGF.EmitCastToVoidPtr(getAtomicPointer())), 1516 CGF.getContext().VoidPtrTy); 1517 Args.add(RValue::get(CGF.EmitCastToVoidPtr(AddForLoaded)), 1518 CGF.getContext().VoidPtrTy); 1519 Args.add( 1520 RValue::get(llvm::ConstantInt::get(CGF.IntTy, (int)llvm::toCABI(AO))), 1521 CGF.getContext().IntTy); 1522 emitAtomicLibcall(CGF, "__atomic_load", CGF.getContext().VoidTy, Args); 1523 } 1524 1525 llvm::Value *AtomicInfo::EmitAtomicLoadOp(llvm::AtomicOrdering AO, 1526 bool IsVolatile) { 1527 // Okay, we're doing this natively. 1528 Address Addr = getAtomicAddressAsAtomicIntPointer(); 1529 llvm::LoadInst *Load = CGF.Builder.CreateLoad(Addr, "atomic-load"); 1530 Load->setAtomic(AO); 1531 1532 // Other decoration. 1533 if (IsVolatile) 1534 Load->setVolatile(true); 1535 CGF.CGM.DecorateInstructionWithTBAA(Load, LVal.getTBAAInfo()); 1536 return Load; 1537 } 1538 1539 /// An LValue is a candidate for having its loads and stores be made atomic if 1540 /// we are operating under /volatile:ms *and* the LValue itself is volatile and 1541 /// performing such an operation can be performed without a libcall. 1542 bool CodeGenFunction::LValueIsSuitableForInlineAtomic(LValue LV) { 1543 if (!CGM.getCodeGenOpts().MSVolatile) return false; 1544 AtomicInfo AI(*this, LV); 1545 bool IsVolatile = LV.isVolatile() || hasVolatileMember(LV.getType()); 1546 // An atomic is inline if we don't need to use a libcall. 1547 bool AtomicIsInline = !AI.shouldUseLibcall(); 1548 // MSVC doesn't seem to do this for types wider than a pointer. 1549 if (getContext().getTypeSize(LV.getType()) > 1550 getContext().getTypeSize(getContext().getIntPtrType())) 1551 return false; 1552 return IsVolatile && AtomicIsInline; 1553 } 1554 1555 RValue CodeGenFunction::EmitAtomicLoad(LValue LV, SourceLocation SL, 1556 AggValueSlot Slot) { 1557 llvm::AtomicOrdering AO; 1558 bool IsVolatile = LV.isVolatileQualified(); 1559 if (LV.getType()->isAtomicType()) { 1560 AO = llvm::AtomicOrdering::SequentiallyConsistent; 1561 } else { 1562 AO = llvm::AtomicOrdering::Acquire; 1563 IsVolatile = true; 1564 } 1565 return EmitAtomicLoad(LV, SL, AO, IsVolatile, Slot); 1566 } 1567 1568 RValue AtomicInfo::EmitAtomicLoad(AggValueSlot ResultSlot, SourceLocation Loc, 1569 bool AsValue, llvm::AtomicOrdering AO, 1570 bool IsVolatile) { 1571 // Check whether we should use a library call. 1572 if (shouldUseLibcall()) { 1573 Address TempAddr = Address::invalid(); 1574 if (LVal.isSimple() && !ResultSlot.isIgnored()) { 1575 assert(getEvaluationKind() == TEK_Aggregate); 1576 TempAddr = ResultSlot.getAddress(); 1577 } else 1578 TempAddr = CreateTempAlloca(); 1579 1580 EmitAtomicLoadLibcall(TempAddr.getPointer(), AO, IsVolatile); 1581 1582 // Okay, turn that back into the original value or whole atomic (for 1583 // non-simple lvalues) type. 1584 return convertAtomicTempToRValue(TempAddr, ResultSlot, Loc, AsValue); 1585 } 1586 1587 // Okay, we're doing this natively. 1588 auto *Load = EmitAtomicLoadOp(AO, IsVolatile); 1589 1590 // If we're ignoring an aggregate return, don't do anything. 1591 if (getEvaluationKind() == TEK_Aggregate && ResultSlot.isIgnored()) 1592 return RValue::getAggregate(Address::invalid(), false); 1593 1594 // Okay, turn that back into the original value or atomic (for non-simple 1595 // lvalues) type. 1596 return ConvertIntToValueOrAtomic(Load, ResultSlot, Loc, AsValue); 1597 } 1598 1599 /// Emit a load from an l-value of atomic type. Note that the r-value 1600 /// we produce is an r-value of the atomic *value* type. 1601 RValue CodeGenFunction::EmitAtomicLoad(LValue src, SourceLocation loc, 1602 llvm::AtomicOrdering AO, bool IsVolatile, 1603 AggValueSlot resultSlot) { 1604 AtomicInfo Atomics(*this, src); 1605 return Atomics.EmitAtomicLoad(resultSlot, loc, /*AsValue=*/true, AO, 1606 IsVolatile); 1607 } 1608 1609 /// Copy an r-value into memory as part of storing to an atomic type. 1610 /// This needs to create a bit-pattern suitable for atomic operations. 1611 void AtomicInfo::emitCopyIntoMemory(RValue rvalue) const { 1612 assert(LVal.isSimple()); 1613 // If we have an r-value, the rvalue should be of the atomic type, 1614 // which means that the caller is responsible for having zeroed 1615 // any padding. Just do an aggregate copy of that type. 1616 if (rvalue.isAggregate()) { 1617 LValue Dest = CGF.MakeAddrLValue(getAtomicAddress(), getAtomicType()); 1618 LValue Src = CGF.MakeAddrLValue(rvalue.getAggregateAddress(), 1619 getAtomicType()); 1620 bool IsVolatile = rvalue.isVolatileQualified() || 1621 LVal.isVolatileQualified(); 1622 CGF.EmitAggregateCopy(Dest, Src, getAtomicType(), 1623 AggValueSlot::DoesNotOverlap, IsVolatile); 1624 return; 1625 } 1626 1627 // Okay, otherwise we're copying stuff. 1628 1629 // Zero out the buffer if necessary. 1630 emitMemSetZeroIfNecessary(); 1631 1632 // Drill past the padding if present. 1633 LValue TempLVal = projectValue(); 1634 1635 // Okay, store the rvalue in. 1636 if (rvalue.isScalar()) { 1637 CGF.EmitStoreOfScalar(rvalue.getScalarVal(), TempLVal, /*init*/ true); 1638 } else { 1639 CGF.EmitStoreOfComplex(rvalue.getComplexVal(), TempLVal, /*init*/ true); 1640 } 1641 } 1642 1643 1644 /// Materialize an r-value into memory for the purposes of storing it 1645 /// to an atomic type. 1646 Address AtomicInfo::materializeRValue(RValue rvalue) const { 1647 // Aggregate r-values are already in memory, and EmitAtomicStore 1648 // requires them to be values of the atomic type. 1649 if (rvalue.isAggregate()) 1650 return rvalue.getAggregateAddress(); 1651 1652 // Otherwise, make a temporary and materialize into it. 1653 LValue TempLV = CGF.MakeAddrLValue(CreateTempAlloca(), getAtomicType()); 1654 AtomicInfo Atomics(CGF, TempLV); 1655 Atomics.emitCopyIntoMemory(rvalue); 1656 return TempLV.getAddress(CGF); 1657 } 1658 1659 llvm::Value *AtomicInfo::convertRValueToInt(RValue RVal) const { 1660 // If we've got a scalar value of the right size, try to avoid going 1661 // through memory. 1662 if (RVal.isScalar() && (!hasPadding() || !LVal.isSimple())) { 1663 llvm::Value *Value = RVal.getScalarVal(); 1664 if (isa<llvm::IntegerType>(Value->getType())) 1665 return CGF.EmitToMemory(Value, ValueTy); 1666 else { 1667 llvm::IntegerType *InputIntTy = llvm::IntegerType::get( 1668 CGF.getLLVMContext(), 1669 LVal.isSimple() ? getValueSizeInBits() : getAtomicSizeInBits()); 1670 if (isa<llvm::PointerType>(Value->getType())) 1671 return CGF.Builder.CreatePtrToInt(Value, InputIntTy); 1672 else if (llvm::BitCastInst::isBitCastable(Value->getType(), InputIntTy)) 1673 return CGF.Builder.CreateBitCast(Value, InputIntTy); 1674 } 1675 } 1676 // Otherwise, we need to go through memory. 1677 // Put the r-value in memory. 1678 Address Addr = materializeRValue(RVal); 1679 1680 // Cast the temporary to the atomic int type and pull a value out. 1681 Addr = emitCastToAtomicIntPointer(Addr); 1682 return CGF.Builder.CreateLoad(Addr); 1683 } 1684 1685 std::pair<llvm::Value *, llvm::Value *> AtomicInfo::EmitAtomicCompareExchangeOp( 1686 llvm::Value *ExpectedVal, llvm::Value *DesiredVal, 1687 llvm::AtomicOrdering Success, llvm::AtomicOrdering Failure, bool IsWeak) { 1688 // Do the atomic store. 1689 Address Addr = getAtomicAddressAsAtomicIntPointer(); 1690 auto *Inst = CGF.Builder.CreateAtomicCmpXchg(Addr.getPointer(), 1691 ExpectedVal, DesiredVal, 1692 Success, Failure); 1693 // Other decoration. 1694 Inst->setVolatile(LVal.isVolatileQualified()); 1695 Inst->setWeak(IsWeak); 1696 1697 // Okay, turn that back into the original value type. 1698 auto *PreviousVal = CGF.Builder.CreateExtractValue(Inst, /*Idxs=*/0); 1699 auto *SuccessFailureVal = CGF.Builder.CreateExtractValue(Inst, /*Idxs=*/1); 1700 return std::make_pair(PreviousVal, SuccessFailureVal); 1701 } 1702 1703 llvm::Value * 1704 AtomicInfo::EmitAtomicCompareExchangeLibcall(llvm::Value *ExpectedAddr, 1705 llvm::Value *DesiredAddr, 1706 llvm::AtomicOrdering Success, 1707 llvm::AtomicOrdering Failure) { 1708 // bool __atomic_compare_exchange(size_t size, void *obj, void *expected, 1709 // void *desired, int success, int failure); 1710 CallArgList Args; 1711 Args.add(RValue::get(getAtomicSizeValue()), CGF.getContext().getSizeType()); 1712 Args.add(RValue::get(CGF.EmitCastToVoidPtr(getAtomicPointer())), 1713 CGF.getContext().VoidPtrTy); 1714 Args.add(RValue::get(CGF.EmitCastToVoidPtr(ExpectedAddr)), 1715 CGF.getContext().VoidPtrTy); 1716 Args.add(RValue::get(CGF.EmitCastToVoidPtr(DesiredAddr)), 1717 CGF.getContext().VoidPtrTy); 1718 Args.add(RValue::get( 1719 llvm::ConstantInt::get(CGF.IntTy, (int)llvm::toCABI(Success))), 1720 CGF.getContext().IntTy); 1721 Args.add(RValue::get( 1722 llvm::ConstantInt::get(CGF.IntTy, (int)llvm::toCABI(Failure))), 1723 CGF.getContext().IntTy); 1724 auto SuccessFailureRVal = emitAtomicLibcall(CGF, "__atomic_compare_exchange", 1725 CGF.getContext().BoolTy, Args); 1726 1727 return SuccessFailureRVal.getScalarVal(); 1728 } 1729 1730 std::pair<RValue, llvm::Value *> AtomicInfo::EmitAtomicCompareExchange( 1731 RValue Expected, RValue Desired, llvm::AtomicOrdering Success, 1732 llvm::AtomicOrdering Failure, bool IsWeak) { 1733 if (isStrongerThan(Failure, Success)) 1734 // Don't assert on undefined behavior "failure argument shall be no stronger 1735 // than the success argument". 1736 Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(Success); 1737 1738 // Check whether we should use a library call. 1739 if (shouldUseLibcall()) { 1740 // Produce a source address. 1741 Address ExpectedAddr = materializeRValue(Expected); 1742 Address DesiredAddr = materializeRValue(Desired); 1743 auto *Res = EmitAtomicCompareExchangeLibcall(ExpectedAddr.getPointer(), 1744 DesiredAddr.getPointer(), 1745 Success, Failure); 1746 return std::make_pair( 1747 convertAtomicTempToRValue(ExpectedAddr, AggValueSlot::ignored(), 1748 SourceLocation(), /*AsValue=*/false), 1749 Res); 1750 } 1751 1752 // If we've got a scalar value of the right size, try to avoid going 1753 // through memory. 1754 auto *ExpectedVal = convertRValueToInt(Expected); 1755 auto *DesiredVal = convertRValueToInt(Desired); 1756 auto Res = EmitAtomicCompareExchangeOp(ExpectedVal, DesiredVal, Success, 1757 Failure, IsWeak); 1758 return std::make_pair( 1759 ConvertIntToValueOrAtomic(Res.first, AggValueSlot::ignored(), 1760 SourceLocation(), /*AsValue=*/false), 1761 Res.second); 1762 } 1763 1764 static void 1765 EmitAtomicUpdateValue(CodeGenFunction &CGF, AtomicInfo &Atomics, RValue OldRVal, 1766 const llvm::function_ref<RValue(RValue)> &UpdateOp, 1767 Address DesiredAddr) { 1768 RValue UpRVal; 1769 LValue AtomicLVal = Atomics.getAtomicLValue(); 1770 LValue DesiredLVal; 1771 if (AtomicLVal.isSimple()) { 1772 UpRVal = OldRVal; 1773 DesiredLVal = CGF.MakeAddrLValue(DesiredAddr, AtomicLVal.getType()); 1774 } else { 1775 // Build new lvalue for temp address. 1776 Address Ptr = Atomics.materializeRValue(OldRVal); 1777 LValue UpdateLVal; 1778 if (AtomicLVal.isBitField()) { 1779 UpdateLVal = 1780 LValue::MakeBitfield(Ptr, AtomicLVal.getBitFieldInfo(), 1781 AtomicLVal.getType(), 1782 AtomicLVal.getBaseInfo(), 1783 AtomicLVal.getTBAAInfo()); 1784 DesiredLVal = 1785 LValue::MakeBitfield(DesiredAddr, AtomicLVal.getBitFieldInfo(), 1786 AtomicLVal.getType(), AtomicLVal.getBaseInfo(), 1787 AtomicLVal.getTBAAInfo()); 1788 } else if (AtomicLVal.isVectorElt()) { 1789 UpdateLVal = LValue::MakeVectorElt(Ptr, AtomicLVal.getVectorIdx(), 1790 AtomicLVal.getType(), 1791 AtomicLVal.getBaseInfo(), 1792 AtomicLVal.getTBAAInfo()); 1793 DesiredLVal = LValue::MakeVectorElt( 1794 DesiredAddr, AtomicLVal.getVectorIdx(), AtomicLVal.getType(), 1795 AtomicLVal.getBaseInfo(), AtomicLVal.getTBAAInfo()); 1796 } else { 1797 assert(AtomicLVal.isExtVectorElt()); 1798 UpdateLVal = LValue::MakeExtVectorElt(Ptr, AtomicLVal.getExtVectorElts(), 1799 AtomicLVal.getType(), 1800 AtomicLVal.getBaseInfo(), 1801 AtomicLVal.getTBAAInfo()); 1802 DesiredLVal = LValue::MakeExtVectorElt( 1803 DesiredAddr, AtomicLVal.getExtVectorElts(), AtomicLVal.getType(), 1804 AtomicLVal.getBaseInfo(), AtomicLVal.getTBAAInfo()); 1805 } 1806 UpRVal = CGF.EmitLoadOfLValue(UpdateLVal, SourceLocation()); 1807 } 1808 // Store new value in the corresponding memory area. 1809 RValue NewRVal = UpdateOp(UpRVal); 1810 if (NewRVal.isScalar()) { 1811 CGF.EmitStoreThroughLValue(NewRVal, DesiredLVal); 1812 } else { 1813 assert(NewRVal.isComplex()); 1814 CGF.EmitStoreOfComplex(NewRVal.getComplexVal(), DesiredLVal, 1815 /*isInit=*/false); 1816 } 1817 } 1818 1819 void AtomicInfo::EmitAtomicUpdateLibcall( 1820 llvm::AtomicOrdering AO, const llvm::function_ref<RValue(RValue)> &UpdateOp, 1821 bool IsVolatile) { 1822 auto Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(AO); 1823 1824 Address ExpectedAddr = CreateTempAlloca(); 1825 1826 EmitAtomicLoadLibcall(ExpectedAddr.getPointer(), AO, IsVolatile); 1827 auto *ContBB = CGF.createBasicBlock("atomic_cont"); 1828 auto *ExitBB = CGF.createBasicBlock("atomic_exit"); 1829 CGF.EmitBlock(ContBB); 1830 Address DesiredAddr = CreateTempAlloca(); 1831 if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) || 1832 requiresMemSetZero(getAtomicAddress().getElementType())) { 1833 auto *OldVal = CGF.Builder.CreateLoad(ExpectedAddr); 1834 CGF.Builder.CreateStore(OldVal, DesiredAddr); 1835 } 1836 auto OldRVal = convertAtomicTempToRValue(ExpectedAddr, 1837 AggValueSlot::ignored(), 1838 SourceLocation(), /*AsValue=*/false); 1839 EmitAtomicUpdateValue(CGF, *this, OldRVal, UpdateOp, DesiredAddr); 1840 auto *Res = 1841 EmitAtomicCompareExchangeLibcall(ExpectedAddr.getPointer(), 1842 DesiredAddr.getPointer(), 1843 AO, Failure); 1844 CGF.Builder.CreateCondBr(Res, ExitBB, ContBB); 1845 CGF.EmitBlock(ExitBB, /*IsFinished=*/true); 1846 } 1847 1848 void AtomicInfo::EmitAtomicUpdateOp( 1849 llvm::AtomicOrdering AO, const llvm::function_ref<RValue(RValue)> &UpdateOp, 1850 bool IsVolatile) { 1851 auto Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(AO); 1852 1853 // Do the atomic load. 1854 auto *OldVal = EmitAtomicLoadOp(Failure, IsVolatile); 1855 // For non-simple lvalues perform compare-and-swap procedure. 1856 auto *ContBB = CGF.createBasicBlock("atomic_cont"); 1857 auto *ExitBB = CGF.createBasicBlock("atomic_exit"); 1858 auto *CurBB = CGF.Builder.GetInsertBlock(); 1859 CGF.EmitBlock(ContBB); 1860 llvm::PHINode *PHI = CGF.Builder.CreatePHI(OldVal->getType(), 1861 /*NumReservedValues=*/2); 1862 PHI->addIncoming(OldVal, CurBB); 1863 Address NewAtomicAddr = CreateTempAlloca(); 1864 Address NewAtomicIntAddr = emitCastToAtomicIntPointer(NewAtomicAddr); 1865 if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) || 1866 requiresMemSetZero(getAtomicAddress().getElementType())) { 1867 CGF.Builder.CreateStore(PHI, NewAtomicIntAddr); 1868 } 1869 auto OldRVal = ConvertIntToValueOrAtomic(PHI, AggValueSlot::ignored(), 1870 SourceLocation(), /*AsValue=*/false); 1871 EmitAtomicUpdateValue(CGF, *this, OldRVal, UpdateOp, NewAtomicAddr); 1872 auto *DesiredVal = CGF.Builder.CreateLoad(NewAtomicIntAddr); 1873 // Try to write new value using cmpxchg operation. 1874 auto Res = EmitAtomicCompareExchangeOp(PHI, DesiredVal, AO, Failure); 1875 PHI->addIncoming(Res.first, CGF.Builder.GetInsertBlock()); 1876 CGF.Builder.CreateCondBr(Res.second, ExitBB, ContBB); 1877 CGF.EmitBlock(ExitBB, /*IsFinished=*/true); 1878 } 1879 1880 static void EmitAtomicUpdateValue(CodeGenFunction &CGF, AtomicInfo &Atomics, 1881 RValue UpdateRVal, Address DesiredAddr) { 1882 LValue AtomicLVal = Atomics.getAtomicLValue(); 1883 LValue DesiredLVal; 1884 // Build new lvalue for temp address. 1885 if (AtomicLVal.isBitField()) { 1886 DesiredLVal = 1887 LValue::MakeBitfield(DesiredAddr, AtomicLVal.getBitFieldInfo(), 1888 AtomicLVal.getType(), AtomicLVal.getBaseInfo(), 1889 AtomicLVal.getTBAAInfo()); 1890 } else if (AtomicLVal.isVectorElt()) { 1891 DesiredLVal = 1892 LValue::MakeVectorElt(DesiredAddr, AtomicLVal.getVectorIdx(), 1893 AtomicLVal.getType(), AtomicLVal.getBaseInfo(), 1894 AtomicLVal.getTBAAInfo()); 1895 } else { 1896 assert(AtomicLVal.isExtVectorElt()); 1897 DesiredLVal = LValue::MakeExtVectorElt( 1898 DesiredAddr, AtomicLVal.getExtVectorElts(), AtomicLVal.getType(), 1899 AtomicLVal.getBaseInfo(), AtomicLVal.getTBAAInfo()); 1900 } 1901 // Store new value in the corresponding memory area. 1902 assert(UpdateRVal.isScalar()); 1903 CGF.EmitStoreThroughLValue(UpdateRVal, DesiredLVal); 1904 } 1905 1906 void AtomicInfo::EmitAtomicUpdateLibcall(llvm::AtomicOrdering AO, 1907 RValue UpdateRVal, bool IsVolatile) { 1908 auto Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(AO); 1909 1910 Address ExpectedAddr = CreateTempAlloca(); 1911 1912 EmitAtomicLoadLibcall(ExpectedAddr.getPointer(), AO, IsVolatile); 1913 auto *ContBB = CGF.createBasicBlock("atomic_cont"); 1914 auto *ExitBB = CGF.createBasicBlock("atomic_exit"); 1915 CGF.EmitBlock(ContBB); 1916 Address DesiredAddr = CreateTempAlloca(); 1917 if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) || 1918 requiresMemSetZero(getAtomicAddress().getElementType())) { 1919 auto *OldVal = CGF.Builder.CreateLoad(ExpectedAddr); 1920 CGF.Builder.CreateStore(OldVal, DesiredAddr); 1921 } 1922 EmitAtomicUpdateValue(CGF, *this, UpdateRVal, DesiredAddr); 1923 auto *Res = 1924 EmitAtomicCompareExchangeLibcall(ExpectedAddr.getPointer(), 1925 DesiredAddr.getPointer(), 1926 AO, Failure); 1927 CGF.Builder.CreateCondBr(Res, ExitBB, ContBB); 1928 CGF.EmitBlock(ExitBB, /*IsFinished=*/true); 1929 } 1930 1931 void AtomicInfo::EmitAtomicUpdateOp(llvm::AtomicOrdering AO, RValue UpdateRVal, 1932 bool IsVolatile) { 1933 auto Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(AO); 1934 1935 // Do the atomic load. 1936 auto *OldVal = EmitAtomicLoadOp(Failure, IsVolatile); 1937 // For non-simple lvalues perform compare-and-swap procedure. 1938 auto *ContBB = CGF.createBasicBlock("atomic_cont"); 1939 auto *ExitBB = CGF.createBasicBlock("atomic_exit"); 1940 auto *CurBB = CGF.Builder.GetInsertBlock(); 1941 CGF.EmitBlock(ContBB); 1942 llvm::PHINode *PHI = CGF.Builder.CreatePHI(OldVal->getType(), 1943 /*NumReservedValues=*/2); 1944 PHI->addIncoming(OldVal, CurBB); 1945 Address NewAtomicAddr = CreateTempAlloca(); 1946 Address NewAtomicIntAddr = emitCastToAtomicIntPointer(NewAtomicAddr); 1947 if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) || 1948 requiresMemSetZero(getAtomicAddress().getElementType())) { 1949 CGF.Builder.CreateStore(PHI, NewAtomicIntAddr); 1950 } 1951 EmitAtomicUpdateValue(CGF, *this, UpdateRVal, NewAtomicAddr); 1952 auto *DesiredVal = CGF.Builder.CreateLoad(NewAtomicIntAddr); 1953 // Try to write new value using cmpxchg operation. 1954 auto Res = EmitAtomicCompareExchangeOp(PHI, DesiredVal, AO, Failure); 1955 PHI->addIncoming(Res.first, CGF.Builder.GetInsertBlock()); 1956 CGF.Builder.CreateCondBr(Res.second, ExitBB, ContBB); 1957 CGF.EmitBlock(ExitBB, /*IsFinished=*/true); 1958 } 1959 1960 void AtomicInfo::EmitAtomicUpdate( 1961 llvm::AtomicOrdering AO, const llvm::function_ref<RValue(RValue)> &UpdateOp, 1962 bool IsVolatile) { 1963 if (shouldUseLibcall()) { 1964 EmitAtomicUpdateLibcall(AO, UpdateOp, IsVolatile); 1965 } else { 1966 EmitAtomicUpdateOp(AO, UpdateOp, IsVolatile); 1967 } 1968 } 1969 1970 void AtomicInfo::EmitAtomicUpdate(llvm::AtomicOrdering AO, RValue UpdateRVal, 1971 bool IsVolatile) { 1972 if (shouldUseLibcall()) { 1973 EmitAtomicUpdateLibcall(AO, UpdateRVal, IsVolatile); 1974 } else { 1975 EmitAtomicUpdateOp(AO, UpdateRVal, IsVolatile); 1976 } 1977 } 1978 1979 void CodeGenFunction::EmitAtomicStore(RValue rvalue, LValue lvalue, 1980 bool isInit) { 1981 bool IsVolatile = lvalue.isVolatileQualified(); 1982 llvm::AtomicOrdering AO; 1983 if (lvalue.getType()->isAtomicType()) { 1984 AO = llvm::AtomicOrdering::SequentiallyConsistent; 1985 } else { 1986 AO = llvm::AtomicOrdering::Release; 1987 IsVolatile = true; 1988 } 1989 return EmitAtomicStore(rvalue, lvalue, AO, IsVolatile, isInit); 1990 } 1991 1992 /// Emit a store to an l-value of atomic type. 1993 /// 1994 /// Note that the r-value is expected to be an r-value *of the atomic 1995 /// type*; this means that for aggregate r-values, it should include 1996 /// storage for any padding that was necessary. 1997 void CodeGenFunction::EmitAtomicStore(RValue rvalue, LValue dest, 1998 llvm::AtomicOrdering AO, bool IsVolatile, 1999 bool isInit) { 2000 // If this is an aggregate r-value, it should agree in type except 2001 // maybe for address-space qualification. 2002 assert(!rvalue.isAggregate() || 2003 rvalue.getAggregateAddress().getElementType() == 2004 dest.getAddress(*this).getElementType()); 2005 2006 AtomicInfo atomics(*this, dest); 2007 LValue LVal = atomics.getAtomicLValue(); 2008 2009 // If this is an initialization, just put the value there normally. 2010 if (LVal.isSimple()) { 2011 if (isInit) { 2012 atomics.emitCopyIntoMemory(rvalue); 2013 return; 2014 } 2015 2016 // Check whether we should use a library call. 2017 if (atomics.shouldUseLibcall()) { 2018 // Produce a source address. 2019 Address srcAddr = atomics.materializeRValue(rvalue); 2020 2021 // void __atomic_store(size_t size, void *mem, void *val, int order) 2022 CallArgList args; 2023 args.add(RValue::get(atomics.getAtomicSizeValue()), 2024 getContext().getSizeType()); 2025 args.add(RValue::get(EmitCastToVoidPtr(atomics.getAtomicPointer())), 2026 getContext().VoidPtrTy); 2027 args.add(RValue::get(EmitCastToVoidPtr(srcAddr.getPointer())), 2028 getContext().VoidPtrTy); 2029 args.add( 2030 RValue::get(llvm::ConstantInt::get(IntTy, (int)llvm::toCABI(AO))), 2031 getContext().IntTy); 2032 emitAtomicLibcall(*this, "__atomic_store", getContext().VoidTy, args); 2033 return; 2034 } 2035 2036 // Okay, we're doing this natively. 2037 llvm::Value *intValue = atomics.convertRValueToInt(rvalue); 2038 2039 // Do the atomic store. 2040 Address addr = 2041 atomics.emitCastToAtomicIntPointer(atomics.getAtomicAddress()); 2042 intValue = Builder.CreateIntCast( 2043 intValue, addr.getElementType(), /*isSigned=*/false); 2044 llvm::StoreInst *store = Builder.CreateStore(intValue, addr); 2045 2046 if (AO == llvm::AtomicOrdering::Acquire) 2047 AO = llvm::AtomicOrdering::Monotonic; 2048 else if (AO == llvm::AtomicOrdering::AcquireRelease) 2049 AO = llvm::AtomicOrdering::Release; 2050 // Initializations don't need to be atomic. 2051 if (!isInit) 2052 store->setAtomic(AO); 2053 2054 // Other decoration. 2055 if (IsVolatile) 2056 store->setVolatile(true); 2057 CGM.DecorateInstructionWithTBAA(store, dest.getTBAAInfo()); 2058 return; 2059 } 2060 2061 // Emit simple atomic update operation. 2062 atomics.EmitAtomicUpdate(AO, rvalue, IsVolatile); 2063 } 2064 2065 /// Emit a compare-and-exchange op for atomic type. 2066 /// 2067 std::pair<RValue, llvm::Value *> CodeGenFunction::EmitAtomicCompareExchange( 2068 LValue Obj, RValue Expected, RValue Desired, SourceLocation Loc, 2069 llvm::AtomicOrdering Success, llvm::AtomicOrdering Failure, bool IsWeak, 2070 AggValueSlot Slot) { 2071 // If this is an aggregate r-value, it should agree in type except 2072 // maybe for address-space qualification. 2073 assert(!Expected.isAggregate() || 2074 Expected.getAggregateAddress().getElementType() == 2075 Obj.getAddress(*this).getElementType()); 2076 assert(!Desired.isAggregate() || 2077 Desired.getAggregateAddress().getElementType() == 2078 Obj.getAddress(*this).getElementType()); 2079 AtomicInfo Atomics(*this, Obj); 2080 2081 return Atomics.EmitAtomicCompareExchange(Expected, Desired, Success, Failure, 2082 IsWeak); 2083 } 2084 2085 void CodeGenFunction::EmitAtomicUpdate( 2086 LValue LVal, llvm::AtomicOrdering AO, 2087 const llvm::function_ref<RValue(RValue)> &UpdateOp, bool IsVolatile) { 2088 AtomicInfo Atomics(*this, LVal); 2089 Atomics.EmitAtomicUpdate(AO, UpdateOp, IsVolatile); 2090 } 2091 2092 void CodeGenFunction::EmitAtomicInit(Expr *init, LValue dest) { 2093 AtomicInfo atomics(*this, dest); 2094 2095 switch (atomics.getEvaluationKind()) { 2096 case TEK_Scalar: { 2097 llvm::Value *value = EmitScalarExpr(init); 2098 atomics.emitCopyIntoMemory(RValue::get(value)); 2099 return; 2100 } 2101 2102 case TEK_Complex: { 2103 ComplexPairTy value = EmitComplexExpr(init); 2104 atomics.emitCopyIntoMemory(RValue::getComplex(value)); 2105 return; 2106 } 2107 2108 case TEK_Aggregate: { 2109 // Fix up the destination if the initializer isn't an expression 2110 // of atomic type. 2111 bool Zeroed = false; 2112 if (!init->getType()->isAtomicType()) { 2113 Zeroed = atomics.emitMemSetZeroIfNecessary(); 2114 dest = atomics.projectValue(); 2115 } 2116 2117 // Evaluate the expression directly into the destination. 2118 AggValueSlot slot = AggValueSlot::forLValue( 2119 dest, *this, AggValueSlot::IsNotDestructed, 2120 AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased, 2121 AggValueSlot::DoesNotOverlap, 2122 Zeroed ? AggValueSlot::IsZeroed : AggValueSlot::IsNotZeroed); 2123 2124 EmitAggExpr(init, slot); 2125 return; 2126 } 2127 } 2128 llvm_unreachable("bad evaluation kind"); 2129 } 2130
Indexes created Tue Feb 24 08:35:24 UTC 2026