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 CGF.Int8Ty, 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__hip_atomic_compare_exchange_strong: 528 case AtomicExpr::AO__opencl_atomic_compare_exchange_strong: 529 emitAtomicCmpXchgFailureSet(CGF, E, false, Dest, Ptr, Val1, Val2, 530 FailureOrder, Size, Order, Scope); 531 return; 532 case AtomicExpr::AO__c11_atomic_compare_exchange_weak: 533 case AtomicExpr::AO__opencl_atomic_compare_exchange_weak: 534 emitAtomicCmpXchgFailureSet(CGF, E, true, Dest, Ptr, Val1, Val2, 535 FailureOrder, Size, Order, Scope); 536 return; 537 case AtomicExpr::AO__atomic_compare_exchange: 538 case AtomicExpr::AO__atomic_compare_exchange_n: { 539 if (llvm::ConstantInt *IsWeakC = dyn_cast<llvm::ConstantInt>(IsWeak)) { 540 emitAtomicCmpXchgFailureSet(CGF, E, IsWeakC->getZExtValue(), Dest, Ptr, 541 Val1, Val2, FailureOrder, Size, Order, Scope); 542 } else { 543 // Create all the relevant BB's 544 llvm::BasicBlock *StrongBB = 545 CGF.createBasicBlock("cmpxchg.strong", CGF.CurFn); 546 llvm::BasicBlock *WeakBB = CGF.createBasicBlock("cmxchg.weak", CGF.CurFn); 547 llvm::BasicBlock *ContBB = 548 CGF.createBasicBlock("cmpxchg.continue", CGF.CurFn); 549 550 llvm::SwitchInst *SI = CGF.Builder.CreateSwitch(IsWeak, WeakBB); 551 SI->addCase(CGF.Builder.getInt1(false), StrongBB); 552 553 CGF.Builder.SetInsertPoint(StrongBB); 554 emitAtomicCmpXchgFailureSet(CGF, E, false, Dest, Ptr, Val1, Val2, 555 FailureOrder, Size, Order, Scope); 556 CGF.Builder.CreateBr(ContBB); 557 558 CGF.Builder.SetInsertPoint(WeakBB); 559 emitAtomicCmpXchgFailureSet(CGF, E, true, Dest, Ptr, Val1, Val2, 560 FailureOrder, Size, Order, Scope); 561 CGF.Builder.CreateBr(ContBB); 562 563 CGF.Builder.SetInsertPoint(ContBB); 564 } 565 return; 566 } 567 case AtomicExpr::AO__c11_atomic_load: 568 case AtomicExpr::AO__opencl_atomic_load: 569 case AtomicExpr::AO__atomic_load_n: 570 case AtomicExpr::AO__atomic_load: { 571 llvm::LoadInst *Load = CGF.Builder.CreateLoad(Ptr); 572 Load->setAtomic(Order, Scope); 573 Load->setVolatile(E->isVolatile()); 574 CGF.Builder.CreateStore(Load, Dest); 575 return; 576 } 577 578 case AtomicExpr::AO__c11_atomic_store: 579 case AtomicExpr::AO__opencl_atomic_store: 580 case AtomicExpr::AO__atomic_store: 581 case AtomicExpr::AO__atomic_store_n: { 582 llvm::Value *LoadVal1 = CGF.Builder.CreateLoad(Val1); 583 llvm::StoreInst *Store = CGF.Builder.CreateStore(LoadVal1, Ptr); 584 Store->setAtomic(Order, Scope); 585 Store->setVolatile(E->isVolatile()); 586 return; 587 } 588 589 case AtomicExpr::AO__c11_atomic_exchange: 590 case AtomicExpr::AO__hip_atomic_exchange: 591 case AtomicExpr::AO__opencl_atomic_exchange: 592 case AtomicExpr::AO__atomic_exchange_n: 593 case AtomicExpr::AO__atomic_exchange: 594 Op = llvm::AtomicRMWInst::Xchg; 595 break; 596 597 case AtomicExpr::AO__atomic_add_fetch: 598 PostOp = E->getValueType()->isFloatingType() ? llvm::Instruction::FAdd 599 : llvm::Instruction::Add; 600 LLVM_FALLTHROUGH; 601 case AtomicExpr::AO__c11_atomic_fetch_add: 602 case AtomicExpr::AO__hip_atomic_fetch_add: 603 case AtomicExpr::AO__opencl_atomic_fetch_add: 604 case AtomicExpr::AO__atomic_fetch_add: 605 Op = E->getValueType()->isFloatingType() ? llvm::AtomicRMWInst::FAdd 606 : llvm::AtomicRMWInst::Add; 607 break; 608 609 case AtomicExpr::AO__atomic_sub_fetch: 610 PostOp = E->getValueType()->isFloatingType() ? llvm::Instruction::FSub 611 : llvm::Instruction::Sub; 612 LLVM_FALLTHROUGH; 613 case AtomicExpr::AO__c11_atomic_fetch_sub: 614 case AtomicExpr::AO__opencl_atomic_fetch_sub: 615 case AtomicExpr::AO__atomic_fetch_sub: 616 Op = E->getValueType()->isFloatingType() ? llvm::AtomicRMWInst::FSub 617 : llvm::AtomicRMWInst::Sub; 618 break; 619 620 case AtomicExpr::AO__atomic_min_fetch: 621 PostOpMinMax = true; 622 LLVM_FALLTHROUGH; 623 case AtomicExpr::AO__c11_atomic_fetch_min: 624 case AtomicExpr::AO__hip_atomic_fetch_min: 625 case AtomicExpr::AO__opencl_atomic_fetch_min: 626 case AtomicExpr::AO__atomic_fetch_min: 627 Op = E->getValueType()->isSignedIntegerType() ? llvm::AtomicRMWInst::Min 628 : llvm::AtomicRMWInst::UMin; 629 break; 630 631 case AtomicExpr::AO__atomic_max_fetch: 632 PostOpMinMax = true; 633 LLVM_FALLTHROUGH; 634 case AtomicExpr::AO__c11_atomic_fetch_max: 635 case AtomicExpr::AO__hip_atomic_fetch_max: 636 case AtomicExpr::AO__opencl_atomic_fetch_max: 637 case AtomicExpr::AO__atomic_fetch_max: 638 Op = E->getValueType()->isSignedIntegerType() ? llvm::AtomicRMWInst::Max 639 : llvm::AtomicRMWInst::UMax; 640 break; 641 642 case AtomicExpr::AO__atomic_and_fetch: 643 PostOp = llvm::Instruction::And; 644 LLVM_FALLTHROUGH; 645 case AtomicExpr::AO__c11_atomic_fetch_and: 646 case AtomicExpr::AO__hip_atomic_fetch_and: 647 case AtomicExpr::AO__opencl_atomic_fetch_and: 648 case AtomicExpr::AO__atomic_fetch_and: 649 Op = llvm::AtomicRMWInst::And; 650 break; 651 652 case AtomicExpr::AO__atomic_or_fetch: 653 PostOp = llvm::Instruction::Or; 654 LLVM_FALLTHROUGH; 655 case AtomicExpr::AO__c11_atomic_fetch_or: 656 case AtomicExpr::AO__hip_atomic_fetch_or: 657 case AtomicExpr::AO__opencl_atomic_fetch_or: 658 case AtomicExpr::AO__atomic_fetch_or: 659 Op = llvm::AtomicRMWInst::Or; 660 break; 661 662 case AtomicExpr::AO__atomic_xor_fetch: 663 PostOp = llvm::Instruction::Xor; 664 LLVM_FALLTHROUGH; 665 case AtomicExpr::AO__c11_atomic_fetch_xor: 666 case AtomicExpr::AO__hip_atomic_fetch_xor: 667 case AtomicExpr::AO__opencl_atomic_fetch_xor: 668 case AtomicExpr::AO__atomic_fetch_xor: 669 Op = llvm::AtomicRMWInst::Xor; 670 break; 671 672 case AtomicExpr::AO__atomic_nand_fetch: 673 PostOp = llvm::Instruction::And; // the NOT is special cased below 674 LLVM_FALLTHROUGH; 675 case AtomicExpr::AO__c11_atomic_fetch_nand: 676 case AtomicExpr::AO__atomic_fetch_nand: 677 Op = llvm::AtomicRMWInst::Nand; 678 break; 679 } 680 681 llvm::Value *LoadVal1 = CGF.Builder.CreateLoad(Val1); 682 llvm::AtomicRMWInst *RMWI = 683 CGF.Builder.CreateAtomicRMW(Op, Ptr.getPointer(), LoadVal1, Order, Scope); 684 RMWI->setVolatile(E->isVolatile()); 685 686 // For __atomic_*_fetch operations, perform the operation again to 687 // determine the value which was written. 688 llvm::Value *Result = RMWI; 689 if (PostOpMinMax) 690 Result = EmitPostAtomicMinMax(CGF.Builder, E->getOp(), 691 E->getValueType()->isSignedIntegerType(), 692 RMWI, LoadVal1); 693 else if (PostOp) 694 Result = CGF.Builder.CreateBinOp((llvm::Instruction::BinaryOps)PostOp, RMWI, 695 LoadVal1); 696 if (E->getOp() == AtomicExpr::AO__atomic_nand_fetch) 697 Result = CGF.Builder.CreateNot(Result); 698 CGF.Builder.CreateStore(Result, Dest); 699 } 700 701 // This function emits any expression (scalar, complex, or aggregate) 702 // into a temporary alloca. 703 static Address 704 EmitValToTemp(CodeGenFunction &CGF, Expr *E) { 705 Address DeclPtr = CGF.CreateMemTemp(E->getType(), ".atomictmp"); 706 CGF.EmitAnyExprToMem(E, DeclPtr, E->getType().getQualifiers(), 707 /*Init*/ true); 708 return DeclPtr; 709 } 710 711 static void EmitAtomicOp(CodeGenFunction &CGF, AtomicExpr *Expr, Address Dest, 712 Address Ptr, Address Val1, Address Val2, 713 llvm::Value *IsWeak, llvm::Value *FailureOrder, 714 uint64_t Size, llvm::AtomicOrdering Order, 715 llvm::Value *Scope) { 716 auto ScopeModel = Expr->getScopeModel(); 717 718 // LLVM atomic instructions always have synch scope. If clang atomic 719 // expression has no scope operand, use default LLVM synch scope. 720 if (!ScopeModel) { 721 EmitAtomicOp(CGF, Expr, Dest, Ptr, Val1, Val2, IsWeak, FailureOrder, Size, 722 Order, CGF.CGM.getLLVMContext().getOrInsertSyncScopeID("")); 723 return; 724 } 725 726 // Handle constant scope. 727 if (auto SC = dyn_cast<llvm::ConstantInt>(Scope)) { 728 auto SCID = CGF.getTargetHooks().getLLVMSyncScopeID( 729 CGF.CGM.getLangOpts(), ScopeModel->map(SC->getZExtValue()), 730 Order, CGF.CGM.getLLVMContext()); 731 EmitAtomicOp(CGF, Expr, Dest, Ptr, Val1, Val2, IsWeak, FailureOrder, Size, 732 Order, SCID); 733 return; 734 } 735 736 // Handle non-constant scope. 737 auto &Builder = CGF.Builder; 738 auto Scopes = ScopeModel->getRuntimeValues(); 739 llvm::DenseMap<unsigned, llvm::BasicBlock *> BB; 740 for (auto S : Scopes) 741 BB[S] = CGF.createBasicBlock(getAsString(ScopeModel->map(S)), CGF.CurFn); 742 743 llvm::BasicBlock *ContBB = 744 CGF.createBasicBlock("atomic.scope.continue", CGF.CurFn); 745 746 auto *SC = Builder.CreateIntCast(Scope, Builder.getInt32Ty(), false); 747 // If unsupported synch scope is encountered at run time, assume a fallback 748 // synch scope value. 749 auto FallBack = ScopeModel->getFallBackValue(); 750 llvm::SwitchInst *SI = Builder.CreateSwitch(SC, BB[FallBack]); 751 for (auto S : Scopes) { 752 auto *B = BB[S]; 753 if (S != FallBack) 754 SI->addCase(Builder.getInt32(S), B); 755 756 Builder.SetInsertPoint(B); 757 EmitAtomicOp(CGF, Expr, Dest, Ptr, Val1, Val2, IsWeak, FailureOrder, Size, 758 Order, 759 CGF.getTargetHooks().getLLVMSyncScopeID(CGF.CGM.getLangOpts(), 760 ScopeModel->map(S), 761 Order, 762 CGF.getLLVMContext())); 763 Builder.CreateBr(ContBB); 764 } 765 766 Builder.SetInsertPoint(ContBB); 767 } 768 769 static void 770 AddDirectArgument(CodeGenFunction &CGF, CallArgList &Args, 771 bool UseOptimizedLibcall, llvm::Value *Val, QualType ValTy, 772 SourceLocation Loc, CharUnits SizeInChars) { 773 if (UseOptimizedLibcall) { 774 // Load value and pass it to the function directly. 775 CharUnits Align = CGF.getContext().getTypeAlignInChars(ValTy); 776 int64_t SizeInBits = CGF.getContext().toBits(SizeInChars); 777 ValTy = 778 CGF.getContext().getIntTypeForBitwidth(SizeInBits, /*Signed=*/false); 779 llvm::Type *IPtrTy = llvm::IntegerType::get(CGF.getLLVMContext(), 780 SizeInBits)->getPointerTo(); 781 Address Ptr = Address(CGF.Builder.CreateBitCast(Val, IPtrTy), Align); 782 Val = CGF.EmitLoadOfScalar(Ptr, false, 783 CGF.getContext().getPointerType(ValTy), 784 Loc); 785 // Coerce the value into an appropriately sized integer type. 786 Args.add(RValue::get(Val), ValTy); 787 } else { 788 // Non-optimized functions always take a reference. 789 Args.add(RValue::get(CGF.EmitCastToVoidPtr(Val)), 790 CGF.getContext().VoidPtrTy); 791 } 792 } 793 794 RValue CodeGenFunction::EmitAtomicExpr(AtomicExpr *E) { 795 QualType AtomicTy = E->getPtr()->getType()->getPointeeType(); 796 QualType MemTy = AtomicTy; 797 if (const AtomicType *AT = AtomicTy->getAs<AtomicType>()) 798 MemTy = AT->getValueType(); 799 llvm::Value *IsWeak = nullptr, *OrderFail = nullptr; 800 801 Address Val1 = Address::invalid(); 802 Address Val2 = Address::invalid(); 803 Address Dest = Address::invalid(); 804 Address Ptr = EmitPointerWithAlignment(E->getPtr()); 805 806 if (E->getOp() == AtomicExpr::AO__c11_atomic_init || 807 E->getOp() == AtomicExpr::AO__opencl_atomic_init) { 808 LValue lvalue = MakeAddrLValue(Ptr, AtomicTy); 809 EmitAtomicInit(E->getVal1(), lvalue); 810 return RValue::get(nullptr); 811 } 812 813 auto TInfo = getContext().getTypeInfoInChars(AtomicTy); 814 uint64_t Size = TInfo.Width.getQuantity(); 815 unsigned MaxInlineWidthInBits = getTarget().getMaxAtomicInlineWidth(); 816 817 bool Oversized = getContext().toBits(TInfo.Width) > MaxInlineWidthInBits; 818 bool Misaligned = (Ptr.getAlignment() % TInfo.Width) != 0; 819 bool UseLibcall = Misaligned | Oversized; 820 bool ShouldCastToIntPtrTy = true; 821 822 CharUnits MaxInlineWidth = 823 getContext().toCharUnitsFromBits(MaxInlineWidthInBits); 824 825 DiagnosticsEngine &Diags = CGM.getDiags(); 826 827 if (Misaligned) { 828 Diags.Report(E->getBeginLoc(), diag::warn_atomic_op_misaligned) 829 << (int)TInfo.Width.getQuantity() 830 << (int)Ptr.getAlignment().getQuantity(); 831 } 832 833 if (Oversized) { 834 Diags.Report(E->getBeginLoc(), diag::warn_atomic_op_oversized) 835 << (int)TInfo.Width.getQuantity() << (int)MaxInlineWidth.getQuantity(); 836 } 837 838 llvm::Value *Order = EmitScalarExpr(E->getOrder()); 839 llvm::Value *Scope = 840 E->getScopeModel() ? EmitScalarExpr(E->getScope()) : nullptr; 841 842 switch (E->getOp()) { 843 case AtomicExpr::AO__c11_atomic_init: 844 case AtomicExpr::AO__opencl_atomic_init: 845 llvm_unreachable("Already handled above with EmitAtomicInit!"); 846 847 case AtomicExpr::AO__c11_atomic_load: 848 case AtomicExpr::AO__opencl_atomic_load: 849 case AtomicExpr::AO__atomic_load_n: 850 break; 851 852 case AtomicExpr::AO__atomic_load: 853 Dest = EmitPointerWithAlignment(E->getVal1()); 854 break; 855 856 case AtomicExpr::AO__atomic_store: 857 Val1 = EmitPointerWithAlignment(E->getVal1()); 858 break; 859 860 case AtomicExpr::AO__atomic_exchange: 861 Val1 = EmitPointerWithAlignment(E->getVal1()); 862 Dest = EmitPointerWithAlignment(E->getVal2()); 863 break; 864 865 case AtomicExpr::AO__c11_atomic_compare_exchange_strong: 866 case AtomicExpr::AO__c11_atomic_compare_exchange_weak: 867 case AtomicExpr::AO__opencl_atomic_compare_exchange_strong: 868 case AtomicExpr::AO__hip_atomic_compare_exchange_strong: 869 case AtomicExpr::AO__opencl_atomic_compare_exchange_weak: 870 case AtomicExpr::AO__atomic_compare_exchange_n: 871 case AtomicExpr::AO__atomic_compare_exchange: 872 Val1 = EmitPointerWithAlignment(E->getVal1()); 873 if (E->getOp() == AtomicExpr::AO__atomic_compare_exchange) 874 Val2 = EmitPointerWithAlignment(E->getVal2()); 875 else 876 Val2 = EmitValToTemp(*this, E->getVal2()); 877 OrderFail = EmitScalarExpr(E->getOrderFail()); 878 if (E->getOp() == AtomicExpr::AO__atomic_compare_exchange_n || 879 E->getOp() == AtomicExpr::AO__atomic_compare_exchange) 880 IsWeak = EmitScalarExpr(E->getWeak()); 881 break; 882 883 case AtomicExpr::AO__c11_atomic_fetch_add: 884 case AtomicExpr::AO__c11_atomic_fetch_sub: 885 case AtomicExpr::AO__hip_atomic_fetch_add: 886 case AtomicExpr::AO__opencl_atomic_fetch_add: 887 case AtomicExpr::AO__opencl_atomic_fetch_sub: 888 if (MemTy->isPointerType()) { 889 // For pointer arithmetic, we're required to do a bit of math: 890 // adding 1 to an int* is not the same as adding 1 to a uintptr_t. 891 // ... but only for the C11 builtins. The GNU builtins expect the 892 // user to multiply by sizeof(T). 893 QualType Val1Ty = E->getVal1()->getType(); 894 llvm::Value *Val1Scalar = EmitScalarExpr(E->getVal1()); 895 CharUnits PointeeIncAmt = 896 getContext().getTypeSizeInChars(MemTy->getPointeeType()); 897 Val1Scalar = Builder.CreateMul(Val1Scalar, CGM.getSize(PointeeIncAmt)); 898 auto Temp = CreateMemTemp(Val1Ty, ".atomictmp"); 899 Val1 = Temp; 900 EmitStoreOfScalar(Val1Scalar, MakeAddrLValue(Temp, Val1Ty)); 901 break; 902 } 903 LLVM_FALLTHROUGH; 904 case AtomicExpr::AO__atomic_fetch_add: 905 case AtomicExpr::AO__atomic_fetch_sub: 906 case AtomicExpr::AO__atomic_add_fetch: 907 case AtomicExpr::AO__atomic_sub_fetch: 908 ShouldCastToIntPtrTy = !MemTy->isFloatingType(); 909 LLVM_FALLTHROUGH; 910 911 case AtomicExpr::AO__c11_atomic_store: 912 case AtomicExpr::AO__c11_atomic_exchange: 913 case AtomicExpr::AO__opencl_atomic_store: 914 case AtomicExpr::AO__opencl_atomic_exchange: 915 case AtomicExpr::AO__hip_atomic_exchange: 916 case AtomicExpr::AO__atomic_store_n: 917 case AtomicExpr::AO__atomic_exchange_n: 918 case AtomicExpr::AO__c11_atomic_fetch_and: 919 case AtomicExpr::AO__c11_atomic_fetch_or: 920 case AtomicExpr::AO__c11_atomic_fetch_xor: 921 case AtomicExpr::AO__c11_atomic_fetch_nand: 922 case AtomicExpr::AO__c11_atomic_fetch_max: 923 case AtomicExpr::AO__c11_atomic_fetch_min: 924 case AtomicExpr::AO__opencl_atomic_fetch_and: 925 case AtomicExpr::AO__opencl_atomic_fetch_or: 926 case AtomicExpr::AO__opencl_atomic_fetch_xor: 927 case AtomicExpr::AO__opencl_atomic_fetch_min: 928 case AtomicExpr::AO__opencl_atomic_fetch_max: 929 case AtomicExpr::AO__atomic_fetch_and: 930 case AtomicExpr::AO__hip_atomic_fetch_and: 931 case AtomicExpr::AO__atomic_fetch_or: 932 case AtomicExpr::AO__hip_atomic_fetch_or: 933 case AtomicExpr::AO__atomic_fetch_xor: 934 case AtomicExpr::AO__hip_atomic_fetch_xor: 935 case AtomicExpr::AO__atomic_fetch_nand: 936 case AtomicExpr::AO__atomic_and_fetch: 937 case AtomicExpr::AO__atomic_or_fetch: 938 case AtomicExpr::AO__atomic_xor_fetch: 939 case AtomicExpr::AO__atomic_nand_fetch: 940 case AtomicExpr::AO__atomic_max_fetch: 941 case AtomicExpr::AO__atomic_min_fetch: 942 case AtomicExpr::AO__atomic_fetch_max: 943 case AtomicExpr::AO__hip_atomic_fetch_max: 944 case AtomicExpr::AO__atomic_fetch_min: 945 case AtomicExpr::AO__hip_atomic_fetch_min: 946 Val1 = EmitValToTemp(*this, E->getVal1()); 947 break; 948 } 949 950 QualType RValTy = E->getType().getUnqualifiedType(); 951 952 // The inlined atomics only function on iN types, where N is a power of 2. We 953 // need to make sure (via temporaries if necessary) that all incoming values 954 // are compatible. 955 LValue AtomicVal = MakeAddrLValue(Ptr, AtomicTy); 956 AtomicInfo Atomics(*this, AtomicVal); 957 958 if (ShouldCastToIntPtrTy) { 959 Ptr = Atomics.emitCastToAtomicIntPointer(Ptr); 960 if (Val1.isValid()) 961 Val1 = Atomics.convertToAtomicIntPointer(Val1); 962 if (Val2.isValid()) 963 Val2 = Atomics.convertToAtomicIntPointer(Val2); 964 } 965 if (Dest.isValid()) { 966 if (ShouldCastToIntPtrTy) 967 Dest = Atomics.emitCastToAtomicIntPointer(Dest); 968 } else if (E->isCmpXChg()) 969 Dest = CreateMemTemp(RValTy, "cmpxchg.bool"); 970 else if (!RValTy->isVoidType()) { 971 Dest = Atomics.CreateTempAlloca(); 972 if (ShouldCastToIntPtrTy) 973 Dest = Atomics.emitCastToAtomicIntPointer(Dest); 974 } 975 976 // Use a library call. See: http://gcc.gnu.org/wiki/Atomic/GCCMM/LIbrary . 977 if (UseLibcall) { 978 bool UseOptimizedLibcall = false; 979 switch (E->getOp()) { 980 case AtomicExpr::AO__c11_atomic_init: 981 case AtomicExpr::AO__opencl_atomic_init: 982 llvm_unreachable("Already handled above with EmitAtomicInit!"); 983 984 case AtomicExpr::AO__c11_atomic_fetch_add: 985 case AtomicExpr::AO__opencl_atomic_fetch_add: 986 case AtomicExpr::AO__atomic_fetch_add: 987 case AtomicExpr::AO__hip_atomic_fetch_add: 988 case AtomicExpr::AO__c11_atomic_fetch_and: 989 case AtomicExpr::AO__opencl_atomic_fetch_and: 990 case AtomicExpr::AO__hip_atomic_fetch_and: 991 case AtomicExpr::AO__atomic_fetch_and: 992 case AtomicExpr::AO__c11_atomic_fetch_or: 993 case AtomicExpr::AO__opencl_atomic_fetch_or: 994 case AtomicExpr::AO__hip_atomic_fetch_or: 995 case AtomicExpr::AO__atomic_fetch_or: 996 case AtomicExpr::AO__c11_atomic_fetch_nand: 997 case AtomicExpr::AO__atomic_fetch_nand: 998 case AtomicExpr::AO__c11_atomic_fetch_sub: 999 case AtomicExpr::AO__opencl_atomic_fetch_sub: 1000 case AtomicExpr::AO__atomic_fetch_sub: 1001 case AtomicExpr::AO__c11_atomic_fetch_xor: 1002 case AtomicExpr::AO__opencl_atomic_fetch_xor: 1003 case AtomicExpr::AO__opencl_atomic_fetch_min: 1004 case AtomicExpr::AO__opencl_atomic_fetch_max: 1005 case AtomicExpr::AO__atomic_fetch_xor: 1006 case AtomicExpr::AO__hip_atomic_fetch_xor: 1007 case AtomicExpr::AO__c11_atomic_fetch_max: 1008 case AtomicExpr::AO__c11_atomic_fetch_min: 1009 case AtomicExpr::AO__atomic_add_fetch: 1010 case AtomicExpr::AO__atomic_and_fetch: 1011 case AtomicExpr::AO__atomic_nand_fetch: 1012 case AtomicExpr::AO__atomic_or_fetch: 1013 case AtomicExpr::AO__atomic_sub_fetch: 1014 case AtomicExpr::AO__atomic_xor_fetch: 1015 case AtomicExpr::AO__atomic_fetch_max: 1016 case AtomicExpr::AO__hip_atomic_fetch_max: 1017 case AtomicExpr::AO__atomic_fetch_min: 1018 case AtomicExpr::AO__hip_atomic_fetch_min: 1019 case AtomicExpr::AO__atomic_max_fetch: 1020 case AtomicExpr::AO__atomic_min_fetch: 1021 // For these, only library calls for certain sizes exist. 1022 UseOptimizedLibcall = true; 1023 break; 1024 1025 case AtomicExpr::AO__atomic_load: 1026 case AtomicExpr::AO__atomic_store: 1027 case AtomicExpr::AO__atomic_exchange: 1028 case AtomicExpr::AO__atomic_compare_exchange: 1029 // Use the generic version if we don't know that the operand will be 1030 // suitably aligned for the optimized version. 1031 if (Misaligned) 1032 break; 1033 LLVM_FALLTHROUGH; 1034 case AtomicExpr::AO__c11_atomic_load: 1035 case AtomicExpr::AO__c11_atomic_store: 1036 case AtomicExpr::AO__c11_atomic_exchange: 1037 case AtomicExpr::AO__c11_atomic_compare_exchange_weak: 1038 case AtomicExpr::AO__c11_atomic_compare_exchange_strong: 1039 case AtomicExpr::AO__hip_atomic_compare_exchange_strong: 1040 case AtomicExpr::AO__opencl_atomic_load: 1041 case AtomicExpr::AO__opencl_atomic_store: 1042 case AtomicExpr::AO__opencl_atomic_exchange: 1043 case AtomicExpr::AO__hip_atomic_exchange: 1044 case AtomicExpr::AO__opencl_atomic_compare_exchange_weak: 1045 case AtomicExpr::AO__opencl_atomic_compare_exchange_strong: 1046 case AtomicExpr::AO__atomic_load_n: 1047 case AtomicExpr::AO__atomic_store_n: 1048 case AtomicExpr::AO__atomic_exchange_n: 1049 case AtomicExpr::AO__atomic_compare_exchange_n: 1050 // Only use optimized library calls for sizes for which they exist. 1051 // FIXME: Size == 16 optimized library functions exist too. 1052 if (Size == 1 || Size == 2 || Size == 4 || Size == 8) 1053 UseOptimizedLibcall = true; 1054 break; 1055 } 1056 1057 CallArgList Args; 1058 if (!UseOptimizedLibcall) { 1059 // For non-optimized library calls, the size is the first parameter 1060 Args.add(RValue::get(llvm::ConstantInt::get(SizeTy, Size)), 1061 getContext().getSizeType()); 1062 } 1063 // Atomic address is the first or second parameter 1064 // The OpenCL atomic library functions only accept pointer arguments to 1065 // generic address space. 1066 auto CastToGenericAddrSpace = [&](llvm::Value *V, QualType PT) { 1067 if (!E->isOpenCL()) 1068 return V; 1069 auto AS = PT->castAs<PointerType>()->getPointeeType().getAddressSpace(); 1070 if (AS == LangAS::opencl_generic) 1071 return V; 1072 auto DestAS = getContext().getTargetAddressSpace(LangAS::opencl_generic); 1073 auto T = V->getType(); 1074 auto *DestType = T->getPointerElementType()->getPointerTo(DestAS); 1075 1076 return getTargetHooks().performAddrSpaceCast( 1077 *this, V, AS, LangAS::opencl_generic, DestType, false); 1078 }; 1079 1080 Args.add(RValue::get(CastToGenericAddrSpace( 1081 EmitCastToVoidPtr(Ptr.getPointer()), E->getPtr()->getType())), 1082 getContext().VoidPtrTy); 1083 1084 std::string LibCallName; 1085 QualType LoweredMemTy = 1086 MemTy->isPointerType() ? getContext().getIntPtrType() : MemTy; 1087 QualType RetTy; 1088 bool HaveRetTy = false; 1089 llvm::Instruction::BinaryOps PostOp = (llvm::Instruction::BinaryOps)0; 1090 bool PostOpMinMax = false; 1091 switch (E->getOp()) { 1092 case AtomicExpr::AO__c11_atomic_init: 1093 case AtomicExpr::AO__opencl_atomic_init: 1094 llvm_unreachable("Already handled!"); 1095 1096 // There is only one libcall for compare an exchange, because there is no 1097 // optimisation benefit possible from a libcall version of a weak compare 1098 // and exchange. 1099 // bool __atomic_compare_exchange(size_t size, void *mem, void *expected, 1100 // void *desired, int success, int failure) 1101 // bool __atomic_compare_exchange_N(T *mem, T *expected, T desired, 1102 // int success, int failure) 1103 case AtomicExpr::AO__c11_atomic_compare_exchange_weak: 1104 case AtomicExpr::AO__c11_atomic_compare_exchange_strong: 1105 case AtomicExpr::AO__opencl_atomic_compare_exchange_weak: 1106 case AtomicExpr::AO__opencl_atomic_compare_exchange_strong: 1107 case AtomicExpr::AO__hip_atomic_compare_exchange_strong: 1108 case AtomicExpr::AO__atomic_compare_exchange: 1109 case AtomicExpr::AO__atomic_compare_exchange_n: 1110 LibCallName = "__atomic_compare_exchange"; 1111 RetTy = getContext().BoolTy; 1112 HaveRetTy = true; 1113 Args.add( 1114 RValue::get(CastToGenericAddrSpace( 1115 EmitCastToVoidPtr(Val1.getPointer()), E->getVal1()->getType())), 1116 getContext().VoidPtrTy); 1117 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val2.getPointer(), 1118 MemTy, E->getExprLoc(), TInfo.Width); 1119 Args.add(RValue::get(Order), getContext().IntTy); 1120 Order = OrderFail; 1121 break; 1122 // void __atomic_exchange(size_t size, void *mem, void *val, void *return, 1123 // int order) 1124 // T __atomic_exchange_N(T *mem, T val, int order) 1125 case AtomicExpr::AO__c11_atomic_exchange: 1126 case AtomicExpr::AO__opencl_atomic_exchange: 1127 case AtomicExpr::AO__atomic_exchange_n: 1128 case AtomicExpr::AO__atomic_exchange: 1129 case AtomicExpr::AO__hip_atomic_exchange: 1130 LibCallName = "__atomic_exchange"; 1131 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1132 MemTy, E->getExprLoc(), TInfo.Width); 1133 break; 1134 // void __atomic_store(size_t size, void *mem, void *val, int order) 1135 // void __atomic_store_N(T *mem, T val, int order) 1136 case AtomicExpr::AO__c11_atomic_store: 1137 case AtomicExpr::AO__opencl_atomic_store: 1138 case AtomicExpr::AO__atomic_store: 1139 case AtomicExpr::AO__atomic_store_n: 1140 LibCallName = "__atomic_store"; 1141 RetTy = getContext().VoidTy; 1142 HaveRetTy = true; 1143 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1144 MemTy, E->getExprLoc(), TInfo.Width); 1145 break; 1146 // void __atomic_load(size_t size, void *mem, void *return, int order) 1147 // T __atomic_load_N(T *mem, int order) 1148 case AtomicExpr::AO__c11_atomic_load: 1149 case AtomicExpr::AO__opencl_atomic_load: 1150 case AtomicExpr::AO__atomic_load: 1151 case AtomicExpr::AO__atomic_load_n: 1152 LibCallName = "__atomic_load"; 1153 break; 1154 // T __atomic_add_fetch_N(T *mem, T val, int order) 1155 // T __atomic_fetch_add_N(T *mem, T val, int order) 1156 case AtomicExpr::AO__atomic_add_fetch: 1157 PostOp = llvm::Instruction::Add; 1158 LLVM_FALLTHROUGH; 1159 case AtomicExpr::AO__c11_atomic_fetch_add: 1160 case AtomicExpr::AO__opencl_atomic_fetch_add: 1161 case AtomicExpr::AO__atomic_fetch_add: 1162 case AtomicExpr::AO__hip_atomic_fetch_add: 1163 LibCallName = "__atomic_fetch_add"; 1164 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1165 LoweredMemTy, E->getExprLoc(), TInfo.Width); 1166 break; 1167 // T __atomic_and_fetch_N(T *mem, T val, int order) 1168 // T __atomic_fetch_and_N(T *mem, T val, int order) 1169 case AtomicExpr::AO__atomic_and_fetch: 1170 PostOp = llvm::Instruction::And; 1171 LLVM_FALLTHROUGH; 1172 case AtomicExpr::AO__c11_atomic_fetch_and: 1173 case AtomicExpr::AO__opencl_atomic_fetch_and: 1174 case AtomicExpr::AO__hip_atomic_fetch_and: 1175 case AtomicExpr::AO__atomic_fetch_and: 1176 LibCallName = "__atomic_fetch_and"; 1177 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1178 MemTy, E->getExprLoc(), TInfo.Width); 1179 break; 1180 // T __atomic_or_fetch_N(T *mem, T val, int order) 1181 // T __atomic_fetch_or_N(T *mem, T val, int order) 1182 case AtomicExpr::AO__atomic_or_fetch: 1183 PostOp = llvm::Instruction::Or; 1184 LLVM_FALLTHROUGH; 1185 case AtomicExpr::AO__c11_atomic_fetch_or: 1186 case AtomicExpr::AO__opencl_atomic_fetch_or: 1187 case AtomicExpr::AO__hip_atomic_fetch_or: 1188 case AtomicExpr::AO__atomic_fetch_or: 1189 LibCallName = "__atomic_fetch_or"; 1190 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1191 MemTy, E->getExprLoc(), TInfo.Width); 1192 break; 1193 // T __atomic_sub_fetch_N(T *mem, T val, int order) 1194 // T __atomic_fetch_sub_N(T *mem, T val, int order) 1195 case AtomicExpr::AO__atomic_sub_fetch: 1196 PostOp = llvm::Instruction::Sub; 1197 LLVM_FALLTHROUGH; 1198 case AtomicExpr::AO__c11_atomic_fetch_sub: 1199 case AtomicExpr::AO__opencl_atomic_fetch_sub: 1200 case AtomicExpr::AO__atomic_fetch_sub: 1201 LibCallName = "__atomic_fetch_sub"; 1202 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1203 LoweredMemTy, E->getExprLoc(), TInfo.Width); 1204 break; 1205 // T __atomic_xor_fetch_N(T *mem, T val, int order) 1206 // T __atomic_fetch_xor_N(T *mem, T val, int order) 1207 case AtomicExpr::AO__atomic_xor_fetch: 1208 PostOp = llvm::Instruction::Xor; 1209 LLVM_FALLTHROUGH; 1210 case AtomicExpr::AO__c11_atomic_fetch_xor: 1211 case AtomicExpr::AO__opencl_atomic_fetch_xor: 1212 case AtomicExpr::AO__hip_atomic_fetch_xor: 1213 case AtomicExpr::AO__atomic_fetch_xor: 1214 LibCallName = "__atomic_fetch_xor"; 1215 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1216 MemTy, E->getExprLoc(), TInfo.Width); 1217 break; 1218 case AtomicExpr::AO__atomic_min_fetch: 1219 PostOpMinMax = true; 1220 LLVM_FALLTHROUGH; 1221 case AtomicExpr::AO__c11_atomic_fetch_min: 1222 case AtomicExpr::AO__atomic_fetch_min: 1223 case AtomicExpr::AO__hip_atomic_fetch_min: 1224 case AtomicExpr::AO__opencl_atomic_fetch_min: 1225 LibCallName = E->getValueType()->isSignedIntegerType() 1226 ? "__atomic_fetch_min" 1227 : "__atomic_fetch_umin"; 1228 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1229 LoweredMemTy, E->getExprLoc(), TInfo.Width); 1230 break; 1231 case AtomicExpr::AO__atomic_max_fetch: 1232 PostOpMinMax = true; 1233 LLVM_FALLTHROUGH; 1234 case AtomicExpr::AO__c11_atomic_fetch_max: 1235 case AtomicExpr::AO__atomic_fetch_max: 1236 case AtomicExpr::AO__hip_atomic_fetch_max: 1237 case AtomicExpr::AO__opencl_atomic_fetch_max: 1238 LibCallName = E->getValueType()->isSignedIntegerType() 1239 ? "__atomic_fetch_max" 1240 : "__atomic_fetch_umax"; 1241 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1242 LoweredMemTy, E->getExprLoc(), TInfo.Width); 1243 break; 1244 // T __atomic_nand_fetch_N(T *mem, T val, int order) 1245 // T __atomic_fetch_nand_N(T *mem, T val, int order) 1246 case AtomicExpr::AO__atomic_nand_fetch: 1247 PostOp = llvm::Instruction::And; // the NOT is special cased below 1248 LLVM_FALLTHROUGH; 1249 case AtomicExpr::AO__c11_atomic_fetch_nand: 1250 case AtomicExpr::AO__atomic_fetch_nand: 1251 LibCallName = "__atomic_fetch_nand"; 1252 AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1.getPointer(), 1253 MemTy, E->getExprLoc(), TInfo.Width); 1254 break; 1255 } 1256 1257 if (E->isOpenCL()) { 1258 LibCallName = std::string("__opencl") + 1259 StringRef(LibCallName).drop_front(1).str(); 1260 1261 } 1262 // Optimized functions have the size in their name. 1263 if (UseOptimizedLibcall) 1264 LibCallName += "_" + llvm::utostr(Size); 1265 // By default, assume we return a value of the atomic type. 1266 if (!HaveRetTy) { 1267 if (UseOptimizedLibcall) { 1268 // Value is returned directly. 1269 // The function returns an appropriately sized integer type. 1270 RetTy = getContext().getIntTypeForBitwidth( 1271 getContext().toBits(TInfo.Width), /*Signed=*/false); 1272 } else { 1273 // Value is returned through parameter before the order. 1274 RetTy = getContext().VoidTy; 1275 Args.add(RValue::get(EmitCastToVoidPtr(Dest.getPointer())), 1276 getContext().VoidPtrTy); 1277 } 1278 } 1279 // order is always the last parameter 1280 Args.add(RValue::get(Order), 1281 getContext().IntTy); 1282 if (E->isOpenCL()) 1283 Args.add(RValue::get(Scope), getContext().IntTy); 1284 1285 // PostOp is only needed for the atomic_*_fetch operations, and 1286 // thus is only needed for and implemented in the 1287 // UseOptimizedLibcall codepath. 1288 assert(UseOptimizedLibcall || (!PostOp && !PostOpMinMax)); 1289 1290 RValue Res = emitAtomicLibcall(*this, LibCallName, RetTy, Args); 1291 // The value is returned directly from the libcall. 1292 if (E->isCmpXChg()) 1293 return Res; 1294 1295 // The value is returned directly for optimized libcalls but the expr 1296 // provided an out-param. 1297 if (UseOptimizedLibcall && Res.getScalarVal()) { 1298 llvm::Value *ResVal = Res.getScalarVal(); 1299 if (PostOpMinMax) { 1300 llvm::Value *LoadVal1 = Args[1].getRValue(*this).getScalarVal(); 1301 ResVal = EmitPostAtomicMinMax(Builder, E->getOp(), 1302 E->getValueType()->isSignedIntegerType(), 1303 ResVal, LoadVal1); 1304 } else if (PostOp) { 1305 llvm::Value *LoadVal1 = Args[1].getRValue(*this).getScalarVal(); 1306 ResVal = Builder.CreateBinOp(PostOp, ResVal, LoadVal1); 1307 } 1308 if (E->getOp() == AtomicExpr::AO__atomic_nand_fetch) 1309 ResVal = Builder.CreateNot(ResVal); 1310 1311 Builder.CreateStore( 1312 ResVal, 1313 Builder.CreateBitCast(Dest, ResVal->getType()->getPointerTo())); 1314 } 1315 1316 if (RValTy->isVoidType()) 1317 return RValue::get(nullptr); 1318 1319 return convertTempToRValue( 1320 Builder.CreateBitCast(Dest, ConvertTypeForMem(RValTy)->getPointerTo()), 1321 RValTy, E->getExprLoc()); 1322 } 1323 1324 bool IsStore = E->getOp() == AtomicExpr::AO__c11_atomic_store || 1325 E->getOp() == AtomicExpr::AO__opencl_atomic_store || 1326 E->getOp() == AtomicExpr::AO__atomic_store || 1327 E->getOp() == AtomicExpr::AO__atomic_store_n; 1328 bool IsLoad = E->getOp() == AtomicExpr::AO__c11_atomic_load || 1329 E->getOp() == AtomicExpr::AO__opencl_atomic_load || 1330 E->getOp() == AtomicExpr::AO__atomic_load || 1331 E->getOp() == AtomicExpr::AO__atomic_load_n; 1332 1333 if (isa<llvm::ConstantInt>(Order)) { 1334 auto ord = cast<llvm::ConstantInt>(Order)->getZExtValue(); 1335 // We should not ever get to a case where the ordering isn't a valid C ABI 1336 // value, but it's hard to enforce that in general. 1337 if (llvm::isValidAtomicOrderingCABI(ord)) 1338 switch ((llvm::AtomicOrderingCABI)ord) { 1339 case llvm::AtomicOrderingCABI::relaxed: 1340 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1341 llvm::AtomicOrdering::Monotonic, Scope); 1342 break; 1343 case llvm::AtomicOrderingCABI::consume: 1344 case llvm::AtomicOrderingCABI::acquire: 1345 if (IsStore) 1346 break; // Avoid crashing on code with undefined behavior 1347 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1348 llvm::AtomicOrdering::Acquire, Scope); 1349 break; 1350 case llvm::AtomicOrderingCABI::release: 1351 if (IsLoad) 1352 break; // Avoid crashing on code with undefined behavior 1353 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1354 llvm::AtomicOrdering::Release, Scope); 1355 break; 1356 case llvm::AtomicOrderingCABI::acq_rel: 1357 if (IsLoad || IsStore) 1358 break; // Avoid crashing on code with undefined behavior 1359 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1360 llvm::AtomicOrdering::AcquireRelease, Scope); 1361 break; 1362 case llvm::AtomicOrderingCABI::seq_cst: 1363 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1364 llvm::AtomicOrdering::SequentiallyConsistent, Scope); 1365 break; 1366 } 1367 if (RValTy->isVoidType()) 1368 return RValue::get(nullptr); 1369 1370 return convertTempToRValue( 1371 Builder.CreateBitCast(Dest, ConvertTypeForMem(RValTy)->getPointerTo( 1372 Dest.getAddressSpace())), 1373 RValTy, E->getExprLoc()); 1374 } 1375 1376 // Long case, when Order isn't obviously constant. 1377 1378 // Create all the relevant BB's 1379 llvm::BasicBlock *MonotonicBB = nullptr, *AcquireBB = nullptr, 1380 *ReleaseBB = nullptr, *AcqRelBB = nullptr, 1381 *SeqCstBB = nullptr; 1382 MonotonicBB = createBasicBlock("monotonic", CurFn); 1383 if (!IsStore) 1384 AcquireBB = createBasicBlock("acquire", CurFn); 1385 if (!IsLoad) 1386 ReleaseBB = createBasicBlock("release", CurFn); 1387 if (!IsLoad && !IsStore) 1388 AcqRelBB = createBasicBlock("acqrel", CurFn); 1389 SeqCstBB = createBasicBlock("seqcst", CurFn); 1390 llvm::BasicBlock *ContBB = createBasicBlock("atomic.continue", CurFn); 1391 1392 // Create the switch for the split 1393 // MonotonicBB is arbitrarily chosen as the default case; in practice, this 1394 // doesn't matter unless someone is crazy enough to use something that 1395 // doesn't fold to a constant for the ordering. 1396 Order = Builder.CreateIntCast(Order, Builder.getInt32Ty(), false); 1397 llvm::SwitchInst *SI = Builder.CreateSwitch(Order, MonotonicBB); 1398 1399 // Emit all the different atomics 1400 Builder.SetInsertPoint(MonotonicBB); 1401 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1402 llvm::AtomicOrdering::Monotonic, Scope); 1403 Builder.CreateBr(ContBB); 1404 if (!IsStore) { 1405 Builder.SetInsertPoint(AcquireBB); 1406 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1407 llvm::AtomicOrdering::Acquire, Scope); 1408 Builder.CreateBr(ContBB); 1409 SI->addCase(Builder.getInt32((int)llvm::AtomicOrderingCABI::consume), 1410 AcquireBB); 1411 SI->addCase(Builder.getInt32((int)llvm::AtomicOrderingCABI::acquire), 1412 AcquireBB); 1413 } 1414 if (!IsLoad) { 1415 Builder.SetInsertPoint(ReleaseBB); 1416 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1417 llvm::AtomicOrdering::Release, Scope); 1418 Builder.CreateBr(ContBB); 1419 SI->addCase(Builder.getInt32((int)llvm::AtomicOrderingCABI::release), 1420 ReleaseBB); 1421 } 1422 if (!IsLoad && !IsStore) { 1423 Builder.SetInsertPoint(AcqRelBB); 1424 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1425 llvm::AtomicOrdering::AcquireRelease, Scope); 1426 Builder.CreateBr(ContBB); 1427 SI->addCase(Builder.getInt32((int)llvm::AtomicOrderingCABI::acq_rel), 1428 AcqRelBB); 1429 } 1430 Builder.SetInsertPoint(SeqCstBB); 1431 EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, Size, 1432 llvm::AtomicOrdering::SequentiallyConsistent, Scope); 1433 Builder.CreateBr(ContBB); 1434 SI->addCase(Builder.getInt32((int)llvm::AtomicOrderingCABI::seq_cst), 1435 SeqCstBB); 1436 1437 // Cleanup and return 1438 Builder.SetInsertPoint(ContBB); 1439 if (RValTy->isVoidType()) 1440 return RValue::get(nullptr); 1441 1442 assert(Atomics.getValueSizeInBits() <= Atomics.getAtomicSizeInBits()); 1443 return convertTempToRValue( 1444 Builder.CreateBitCast(Dest, ConvertTypeForMem(RValTy)->getPointerTo( 1445 Dest.getAddressSpace())), 1446 RValTy, E->getExprLoc()); 1447 } 1448 1449 Address AtomicInfo::emitCastToAtomicIntPointer(Address addr) const { 1450 unsigned addrspace = 1451 cast<llvm::PointerType>(addr.getPointer()->getType())->getAddressSpace(); 1452 llvm::IntegerType *ty = 1453 llvm::IntegerType::get(CGF.getLLVMContext(), AtomicSizeInBits); 1454 return CGF.Builder.CreateBitCast(addr, ty->getPointerTo(addrspace)); 1455 } 1456 1457 Address AtomicInfo::convertToAtomicIntPointer(Address Addr) const { 1458 llvm::Type *Ty = Addr.getElementType(); 1459 uint64_t SourceSizeInBits = CGF.CGM.getDataLayout().getTypeSizeInBits(Ty); 1460 if (SourceSizeInBits != AtomicSizeInBits) { 1461 Address Tmp = CreateTempAlloca(); 1462 CGF.Builder.CreateMemCpy(Tmp, Addr, 1463 std::min(AtomicSizeInBits, SourceSizeInBits) / 8); 1464 Addr = Tmp; 1465 } 1466 1467 return emitCastToAtomicIntPointer(Addr); 1468 } 1469 1470 RValue AtomicInfo::convertAtomicTempToRValue(Address addr, 1471 AggValueSlot resultSlot, 1472 SourceLocation loc, 1473 bool asValue) const { 1474 if (LVal.isSimple()) { 1475 if (EvaluationKind == TEK_Aggregate) 1476 return resultSlot.asRValue(); 1477 1478 // Drill into the padding structure if we have one. 1479 if (hasPadding()) 1480 addr = CGF.Builder.CreateStructGEP(addr, 0); 1481 1482 // Otherwise, just convert the temporary to an r-value using the 1483 // normal conversion routine. 1484 return CGF.convertTempToRValue(addr, getValueType(), loc); 1485 } 1486 if (!asValue) 1487 // Get RValue from temp memory as atomic for non-simple lvalues 1488 return RValue::get(CGF.Builder.CreateLoad(addr)); 1489 if (LVal.isBitField()) 1490 return CGF.EmitLoadOfBitfieldLValue( 1491 LValue::MakeBitfield(addr, LVal.getBitFieldInfo(), LVal.getType(), 1492 LVal.getBaseInfo(), TBAAAccessInfo()), loc); 1493 if (LVal.isVectorElt()) 1494 return CGF.EmitLoadOfLValue( 1495 LValue::MakeVectorElt(addr, LVal.getVectorIdx(), LVal.getType(), 1496 LVal.getBaseInfo(), TBAAAccessInfo()), loc); 1497 assert(LVal.isExtVectorElt()); 1498 return CGF.EmitLoadOfExtVectorElementLValue(LValue::MakeExtVectorElt( 1499 addr, LVal.getExtVectorElts(), LVal.getType(), 1500 LVal.getBaseInfo(), TBAAAccessInfo())); 1501 } 1502 1503 RValue AtomicInfo::ConvertIntToValueOrAtomic(llvm::Value *IntVal, 1504 AggValueSlot ResultSlot, 1505 SourceLocation Loc, 1506 bool AsValue) const { 1507 // Try not to in some easy cases. 1508 assert(IntVal->getType()->isIntegerTy() && "Expected integer value"); 1509 if (getEvaluationKind() == TEK_Scalar && 1510 (((!LVal.isBitField() || 1511 LVal.getBitFieldInfo().Size == ValueSizeInBits) && 1512 !hasPadding()) || 1513 !AsValue)) { 1514 auto *ValTy = AsValue 1515 ? CGF.ConvertTypeForMem(ValueTy) 1516 : getAtomicAddress().getType()->getPointerElementType(); 1517 if (ValTy->isIntegerTy()) { 1518 assert(IntVal->getType() == ValTy && "Different integer types."); 1519 return RValue::get(CGF.EmitFromMemory(IntVal, ValueTy)); 1520 } else if (ValTy->isPointerTy()) 1521 return RValue::get(CGF.Builder.CreateIntToPtr(IntVal, ValTy)); 1522 else if (llvm::CastInst::isBitCastable(IntVal->getType(), ValTy)) 1523 return RValue::get(CGF.Builder.CreateBitCast(IntVal, ValTy)); 1524 } 1525 1526 // Create a temporary. This needs to be big enough to hold the 1527 // atomic integer. 1528 Address Temp = Address::invalid(); 1529 bool TempIsVolatile = false; 1530 if (AsValue && getEvaluationKind() == TEK_Aggregate) { 1531 assert(!ResultSlot.isIgnored()); 1532 Temp = ResultSlot.getAddress(); 1533 TempIsVolatile = ResultSlot.isVolatile(); 1534 } else { 1535 Temp = CreateTempAlloca(); 1536 } 1537 1538 // Slam the integer into the temporary. 1539 Address CastTemp = emitCastToAtomicIntPointer(Temp); 1540 CGF.Builder.CreateStore(IntVal, CastTemp) 1541 ->setVolatile(TempIsVolatile); 1542 1543 return convertAtomicTempToRValue(Temp, ResultSlot, Loc, AsValue); 1544 } 1545 1546 void AtomicInfo::EmitAtomicLoadLibcall(llvm::Value *AddForLoaded, 1547 llvm::AtomicOrdering AO, bool) { 1548 // void __atomic_load(size_t size, void *mem, void *return, int order); 1549 CallArgList Args; 1550 Args.add(RValue::get(getAtomicSizeValue()), CGF.getContext().getSizeType()); 1551 Args.add(RValue::get(CGF.EmitCastToVoidPtr(getAtomicPointer())), 1552 CGF.getContext().VoidPtrTy); 1553 Args.add(RValue::get(CGF.EmitCastToVoidPtr(AddForLoaded)), 1554 CGF.getContext().VoidPtrTy); 1555 Args.add( 1556 RValue::get(llvm::ConstantInt::get(CGF.IntTy, (int)llvm::toCABI(AO))), 1557 CGF.getContext().IntTy); 1558 emitAtomicLibcall(CGF, "__atomic_load", CGF.getContext().VoidTy, Args); 1559 } 1560 1561 llvm::Value *AtomicInfo::EmitAtomicLoadOp(llvm::AtomicOrdering AO, 1562 bool IsVolatile) { 1563 // Okay, we're doing this natively. 1564 Address Addr = getAtomicAddressAsAtomicIntPointer(); 1565 llvm::LoadInst *Load = CGF.Builder.CreateLoad(Addr, "atomic-load"); 1566 Load->setAtomic(AO); 1567 1568 // Other decoration. 1569 if (IsVolatile) 1570 Load->setVolatile(true); 1571 CGF.CGM.DecorateInstructionWithTBAA(Load, LVal.getTBAAInfo()); 1572 return Load; 1573 } 1574 1575 /// An LValue is a candidate for having its loads and stores be made atomic if 1576 /// we are operating under /volatile:ms *and* the LValue itself is volatile and 1577 /// performing such an operation can be performed without a libcall. 1578 bool CodeGenFunction::LValueIsSuitableForInlineAtomic(LValue LV) { 1579 if (!CGM.getCodeGenOpts().MSVolatile) return false; 1580 AtomicInfo AI(*this, LV); 1581 bool IsVolatile = LV.isVolatile() || hasVolatileMember(LV.getType()); 1582 // An atomic is inline if we don't need to use a libcall. 1583 bool AtomicIsInline = !AI.shouldUseLibcall(); 1584 // MSVC doesn't seem to do this for types wider than a pointer. 1585 if (getContext().getTypeSize(LV.getType()) > 1586 getContext().getTypeSize(getContext().getIntPtrType())) 1587 return false; 1588 return IsVolatile && AtomicIsInline; 1589 } 1590 1591 RValue CodeGenFunction::EmitAtomicLoad(LValue LV, SourceLocation SL, 1592 AggValueSlot Slot) { 1593 llvm::AtomicOrdering AO; 1594 bool IsVolatile = LV.isVolatileQualified(); 1595 if (LV.getType()->isAtomicType()) { 1596 AO = llvm::AtomicOrdering::SequentiallyConsistent; 1597 } else { 1598 AO = llvm::AtomicOrdering::Acquire; 1599 IsVolatile = true; 1600 } 1601 return EmitAtomicLoad(LV, SL, AO, IsVolatile, Slot); 1602 } 1603 1604 RValue AtomicInfo::EmitAtomicLoad(AggValueSlot ResultSlot, SourceLocation Loc, 1605 bool AsValue, llvm::AtomicOrdering AO, 1606 bool IsVolatile) { 1607 // Check whether we should use a library call. 1608 if (shouldUseLibcall()) { 1609 Address TempAddr = Address::invalid(); 1610 if (LVal.isSimple() && !ResultSlot.isIgnored()) { 1611 assert(getEvaluationKind() == TEK_Aggregate); 1612 TempAddr = ResultSlot.getAddress(); 1613 } else 1614 TempAddr = CreateTempAlloca(); 1615 1616 EmitAtomicLoadLibcall(TempAddr.getPointer(), AO, IsVolatile); 1617 1618 // Okay, turn that back into the original value or whole atomic (for 1619 // non-simple lvalues) type. 1620 return convertAtomicTempToRValue(TempAddr, ResultSlot, Loc, AsValue); 1621 } 1622 1623 // Okay, we're doing this natively. 1624 auto *Load = EmitAtomicLoadOp(AO, IsVolatile); 1625 1626 // If we're ignoring an aggregate return, don't do anything. 1627 if (getEvaluationKind() == TEK_Aggregate && ResultSlot.isIgnored()) 1628 return RValue::getAggregate(Address::invalid(), false); 1629 1630 // Okay, turn that back into the original value or atomic (for non-simple 1631 // lvalues) type. 1632 return ConvertIntToValueOrAtomic(Load, ResultSlot, Loc, AsValue); 1633 } 1634 1635 /// Emit a load from an l-value of atomic type. Note that the r-value 1636 /// we produce is an r-value of the atomic *value* type. 1637 RValue CodeGenFunction::EmitAtomicLoad(LValue src, SourceLocation loc, 1638 llvm::AtomicOrdering AO, bool IsVolatile, 1639 AggValueSlot resultSlot) { 1640 AtomicInfo Atomics(*this, src); 1641 return Atomics.EmitAtomicLoad(resultSlot, loc, /*AsValue=*/true, AO, 1642 IsVolatile); 1643 } 1644 1645 /// Copy an r-value into memory as part of storing to an atomic type. 1646 /// This needs to create a bit-pattern suitable for atomic operations. 1647 void AtomicInfo::emitCopyIntoMemory(RValue rvalue) const { 1648 assert(LVal.isSimple()); 1649 // If we have an r-value, the rvalue should be of the atomic type, 1650 // which means that the caller is responsible for having zeroed 1651 // any padding. Just do an aggregate copy of that type. 1652 if (rvalue.isAggregate()) { 1653 LValue Dest = CGF.MakeAddrLValue(getAtomicAddress(), getAtomicType()); 1654 LValue Src = CGF.MakeAddrLValue(rvalue.getAggregateAddress(), 1655 getAtomicType()); 1656 bool IsVolatile = rvalue.isVolatileQualified() || 1657 LVal.isVolatileQualified(); 1658 CGF.EmitAggregateCopy(Dest, Src, getAtomicType(), 1659 AggValueSlot::DoesNotOverlap, IsVolatile); 1660 return; 1661 } 1662 1663 // Okay, otherwise we're copying stuff. 1664 1665 // Zero out the buffer if necessary. 1666 emitMemSetZeroIfNecessary(); 1667 1668 // Drill past the padding if present. 1669 LValue TempLVal = projectValue(); 1670 1671 // Okay, store the rvalue in. 1672 if (rvalue.isScalar()) { 1673 CGF.EmitStoreOfScalar(rvalue.getScalarVal(), TempLVal, /*init*/ true); 1674 } else { 1675 CGF.EmitStoreOfComplex(rvalue.getComplexVal(), TempLVal, /*init*/ true); 1676 } 1677 } 1678 1679 1680 /// Materialize an r-value into memory for the purposes of storing it 1681 /// to an atomic type. 1682 Address AtomicInfo::materializeRValue(RValue rvalue) const { 1683 // Aggregate r-values are already in memory, and EmitAtomicStore 1684 // requires them to be values of the atomic type. 1685 if (rvalue.isAggregate()) 1686 return rvalue.getAggregateAddress(); 1687 1688 // Otherwise, make a temporary and materialize into it. 1689 LValue TempLV = CGF.MakeAddrLValue(CreateTempAlloca(), getAtomicType()); 1690 AtomicInfo Atomics(CGF, TempLV); 1691 Atomics.emitCopyIntoMemory(rvalue); 1692 return TempLV.getAddress(CGF); 1693 } 1694 1695 llvm::Value *AtomicInfo::convertRValueToInt(RValue RVal) const { 1696 // If we've got a scalar value of the right size, try to avoid going 1697 // through memory. 1698 if (RVal.isScalar() && (!hasPadding() || !LVal.isSimple())) { 1699 llvm::Value *Value = RVal.getScalarVal(); 1700 if (isa<llvm::IntegerType>(Value->getType())) 1701 return CGF.EmitToMemory(Value, ValueTy); 1702 else { 1703 llvm::IntegerType *InputIntTy = llvm::IntegerType::get( 1704 CGF.getLLVMContext(), 1705 LVal.isSimple() ? getValueSizeInBits() : getAtomicSizeInBits()); 1706 if (isa<llvm::PointerType>(Value->getType())) 1707 return CGF.Builder.CreatePtrToInt(Value, InputIntTy); 1708 else if (llvm::BitCastInst::isBitCastable(Value->getType(), InputIntTy)) 1709 return CGF.Builder.CreateBitCast(Value, InputIntTy); 1710 } 1711 } 1712 // Otherwise, we need to go through memory. 1713 // Put the r-value in memory. 1714 Address Addr = materializeRValue(RVal); 1715 1716 // Cast the temporary to the atomic int type and pull a value out. 1717 Addr = emitCastToAtomicIntPointer(Addr); 1718 return CGF.Builder.CreateLoad(Addr); 1719 } 1720 1721 std::pair<llvm::Value *, llvm::Value *> AtomicInfo::EmitAtomicCompareExchangeOp( 1722 llvm::Value *ExpectedVal, llvm::Value *DesiredVal, 1723 llvm::AtomicOrdering Success, llvm::AtomicOrdering Failure, bool IsWeak) { 1724 // Do the atomic store. 1725 Address Addr = getAtomicAddressAsAtomicIntPointer(); 1726 auto *Inst = CGF.Builder.CreateAtomicCmpXchg(Addr.getPointer(), 1727 ExpectedVal, DesiredVal, 1728 Success, Failure); 1729 // Other decoration. 1730 Inst->setVolatile(LVal.isVolatileQualified()); 1731 Inst->setWeak(IsWeak); 1732 1733 // Okay, turn that back into the original value type. 1734 auto *PreviousVal = CGF.Builder.CreateExtractValue(Inst, /*Idxs=*/0); 1735 auto *SuccessFailureVal = CGF.Builder.CreateExtractValue(Inst, /*Idxs=*/1); 1736 return std::make_pair(PreviousVal, SuccessFailureVal); 1737 } 1738 1739 llvm::Value * 1740 AtomicInfo::EmitAtomicCompareExchangeLibcall(llvm::Value *ExpectedAddr, 1741 llvm::Value *DesiredAddr, 1742 llvm::AtomicOrdering Success, 1743 llvm::AtomicOrdering Failure) { 1744 // bool __atomic_compare_exchange(size_t size, void *obj, void *expected, 1745 // void *desired, int success, int failure); 1746 CallArgList Args; 1747 Args.add(RValue::get(getAtomicSizeValue()), CGF.getContext().getSizeType()); 1748 Args.add(RValue::get(CGF.EmitCastToVoidPtr(getAtomicPointer())), 1749 CGF.getContext().VoidPtrTy); 1750 Args.add(RValue::get(CGF.EmitCastToVoidPtr(ExpectedAddr)), 1751 CGF.getContext().VoidPtrTy); 1752 Args.add(RValue::get(CGF.EmitCastToVoidPtr(DesiredAddr)), 1753 CGF.getContext().VoidPtrTy); 1754 Args.add(RValue::get( 1755 llvm::ConstantInt::get(CGF.IntTy, (int)llvm::toCABI(Success))), 1756 CGF.getContext().IntTy); 1757 Args.add(RValue::get( 1758 llvm::ConstantInt::get(CGF.IntTy, (int)llvm::toCABI(Failure))), 1759 CGF.getContext().IntTy); 1760 auto SuccessFailureRVal = emitAtomicLibcall(CGF, "__atomic_compare_exchange", 1761 CGF.getContext().BoolTy, Args); 1762 1763 return SuccessFailureRVal.getScalarVal(); 1764 } 1765 1766 std::pair<RValue, llvm::Value *> AtomicInfo::EmitAtomicCompareExchange( 1767 RValue Expected, RValue Desired, llvm::AtomicOrdering Success, 1768 llvm::AtomicOrdering Failure, bool IsWeak) { 1769 // Check whether we should use a library call. 1770 if (shouldUseLibcall()) { 1771 // Produce a source address. 1772 Address ExpectedAddr = materializeRValue(Expected); 1773 Address DesiredAddr = materializeRValue(Desired); 1774 auto *Res = EmitAtomicCompareExchangeLibcall(ExpectedAddr.getPointer(), 1775 DesiredAddr.getPointer(), 1776 Success, Failure); 1777 return std::make_pair( 1778 convertAtomicTempToRValue(ExpectedAddr, AggValueSlot::ignored(), 1779 SourceLocation(), /*AsValue=*/false), 1780 Res); 1781 } 1782 1783 // If we've got a scalar value of the right size, try to avoid going 1784 // through memory. 1785 auto *ExpectedVal = convertRValueToInt(Expected); 1786 auto *DesiredVal = convertRValueToInt(Desired); 1787 auto Res = EmitAtomicCompareExchangeOp(ExpectedVal, DesiredVal, Success, 1788 Failure, IsWeak); 1789 return std::make_pair( 1790 ConvertIntToValueOrAtomic(Res.first, AggValueSlot::ignored(), 1791 SourceLocation(), /*AsValue=*/false), 1792 Res.second); 1793 } 1794 1795 static void 1796 EmitAtomicUpdateValue(CodeGenFunction &CGF, AtomicInfo &Atomics, RValue OldRVal, 1797 const llvm::function_ref<RValue(RValue)> &UpdateOp, 1798 Address DesiredAddr) { 1799 RValue UpRVal; 1800 LValue AtomicLVal = Atomics.getAtomicLValue(); 1801 LValue DesiredLVal; 1802 if (AtomicLVal.isSimple()) { 1803 UpRVal = OldRVal; 1804 DesiredLVal = CGF.MakeAddrLValue(DesiredAddr, AtomicLVal.getType()); 1805 } else { 1806 // Build new lvalue for temp address. 1807 Address Ptr = Atomics.materializeRValue(OldRVal); 1808 LValue UpdateLVal; 1809 if (AtomicLVal.isBitField()) { 1810 UpdateLVal = 1811 LValue::MakeBitfield(Ptr, AtomicLVal.getBitFieldInfo(), 1812 AtomicLVal.getType(), 1813 AtomicLVal.getBaseInfo(), 1814 AtomicLVal.getTBAAInfo()); 1815 DesiredLVal = 1816 LValue::MakeBitfield(DesiredAddr, AtomicLVal.getBitFieldInfo(), 1817 AtomicLVal.getType(), AtomicLVal.getBaseInfo(), 1818 AtomicLVal.getTBAAInfo()); 1819 } else if (AtomicLVal.isVectorElt()) { 1820 UpdateLVal = LValue::MakeVectorElt(Ptr, AtomicLVal.getVectorIdx(), 1821 AtomicLVal.getType(), 1822 AtomicLVal.getBaseInfo(), 1823 AtomicLVal.getTBAAInfo()); 1824 DesiredLVal = LValue::MakeVectorElt( 1825 DesiredAddr, AtomicLVal.getVectorIdx(), AtomicLVal.getType(), 1826 AtomicLVal.getBaseInfo(), AtomicLVal.getTBAAInfo()); 1827 } else { 1828 assert(AtomicLVal.isExtVectorElt()); 1829 UpdateLVal = LValue::MakeExtVectorElt(Ptr, AtomicLVal.getExtVectorElts(), 1830 AtomicLVal.getType(), 1831 AtomicLVal.getBaseInfo(), 1832 AtomicLVal.getTBAAInfo()); 1833 DesiredLVal = LValue::MakeExtVectorElt( 1834 DesiredAddr, AtomicLVal.getExtVectorElts(), AtomicLVal.getType(), 1835 AtomicLVal.getBaseInfo(), AtomicLVal.getTBAAInfo()); 1836 } 1837 UpRVal = CGF.EmitLoadOfLValue(UpdateLVal, SourceLocation()); 1838 } 1839 // Store new value in the corresponding memory area. 1840 RValue NewRVal = UpdateOp(UpRVal); 1841 if (NewRVal.isScalar()) { 1842 CGF.EmitStoreThroughLValue(NewRVal, DesiredLVal); 1843 } else { 1844 assert(NewRVal.isComplex()); 1845 CGF.EmitStoreOfComplex(NewRVal.getComplexVal(), DesiredLVal, 1846 /*isInit=*/false); 1847 } 1848 } 1849 1850 void AtomicInfo::EmitAtomicUpdateLibcall( 1851 llvm::AtomicOrdering AO, const llvm::function_ref<RValue(RValue)> &UpdateOp, 1852 bool IsVolatile) { 1853 auto Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(AO); 1854 1855 Address ExpectedAddr = CreateTempAlloca(); 1856 1857 EmitAtomicLoadLibcall(ExpectedAddr.getPointer(), AO, IsVolatile); 1858 auto *ContBB = CGF.createBasicBlock("atomic_cont"); 1859 auto *ExitBB = CGF.createBasicBlock("atomic_exit"); 1860 CGF.EmitBlock(ContBB); 1861 Address DesiredAddr = CreateTempAlloca(); 1862 if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) || 1863 requiresMemSetZero(getAtomicAddress().getElementType())) { 1864 auto *OldVal = CGF.Builder.CreateLoad(ExpectedAddr); 1865 CGF.Builder.CreateStore(OldVal, DesiredAddr); 1866 } 1867 auto OldRVal = convertAtomicTempToRValue(ExpectedAddr, 1868 AggValueSlot::ignored(), 1869 SourceLocation(), /*AsValue=*/false); 1870 EmitAtomicUpdateValue(CGF, *this, OldRVal, UpdateOp, DesiredAddr); 1871 auto *Res = 1872 EmitAtomicCompareExchangeLibcall(ExpectedAddr.getPointer(), 1873 DesiredAddr.getPointer(), 1874 AO, Failure); 1875 CGF.Builder.CreateCondBr(Res, ExitBB, ContBB); 1876 CGF.EmitBlock(ExitBB, /*IsFinished=*/true); 1877 } 1878 1879 void AtomicInfo::EmitAtomicUpdateOp( 1880 llvm::AtomicOrdering AO, const llvm::function_ref<RValue(RValue)> &UpdateOp, 1881 bool IsVolatile) { 1882 auto Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(AO); 1883 1884 // Do the atomic load. 1885 auto *OldVal = EmitAtomicLoadOp(Failure, IsVolatile); 1886 // For non-simple lvalues perform compare-and-swap procedure. 1887 auto *ContBB = CGF.createBasicBlock("atomic_cont"); 1888 auto *ExitBB = CGF.createBasicBlock("atomic_exit"); 1889 auto *CurBB = CGF.Builder.GetInsertBlock(); 1890 CGF.EmitBlock(ContBB); 1891 llvm::PHINode *PHI = CGF.Builder.CreatePHI(OldVal->getType(), 1892 /*NumReservedValues=*/2); 1893 PHI->addIncoming(OldVal, CurBB); 1894 Address NewAtomicAddr = CreateTempAlloca(); 1895 Address NewAtomicIntAddr = emitCastToAtomicIntPointer(NewAtomicAddr); 1896 if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) || 1897 requiresMemSetZero(getAtomicAddress().getElementType())) { 1898 CGF.Builder.CreateStore(PHI, NewAtomicIntAddr); 1899 } 1900 auto OldRVal = ConvertIntToValueOrAtomic(PHI, AggValueSlot::ignored(), 1901 SourceLocation(), /*AsValue=*/false); 1902 EmitAtomicUpdateValue(CGF, *this, OldRVal, UpdateOp, NewAtomicAddr); 1903 auto *DesiredVal = CGF.Builder.CreateLoad(NewAtomicIntAddr); 1904 // Try to write new value using cmpxchg operation. 1905 auto Res = EmitAtomicCompareExchangeOp(PHI, DesiredVal, AO, Failure); 1906 PHI->addIncoming(Res.first, CGF.Builder.GetInsertBlock()); 1907 CGF.Builder.CreateCondBr(Res.second, ExitBB, ContBB); 1908 CGF.EmitBlock(ExitBB, /*IsFinished=*/true); 1909 } 1910 1911 static void EmitAtomicUpdateValue(CodeGenFunction &CGF, AtomicInfo &Atomics, 1912 RValue UpdateRVal, Address DesiredAddr) { 1913 LValue AtomicLVal = Atomics.getAtomicLValue(); 1914 LValue DesiredLVal; 1915 // Build new lvalue for temp address. 1916 if (AtomicLVal.isBitField()) { 1917 DesiredLVal = 1918 LValue::MakeBitfield(DesiredAddr, AtomicLVal.getBitFieldInfo(), 1919 AtomicLVal.getType(), AtomicLVal.getBaseInfo(), 1920 AtomicLVal.getTBAAInfo()); 1921 } else if (AtomicLVal.isVectorElt()) { 1922 DesiredLVal = 1923 LValue::MakeVectorElt(DesiredAddr, AtomicLVal.getVectorIdx(), 1924 AtomicLVal.getType(), AtomicLVal.getBaseInfo(), 1925 AtomicLVal.getTBAAInfo()); 1926 } else { 1927 assert(AtomicLVal.isExtVectorElt()); 1928 DesiredLVal = LValue::MakeExtVectorElt( 1929 DesiredAddr, AtomicLVal.getExtVectorElts(), AtomicLVal.getType(), 1930 AtomicLVal.getBaseInfo(), AtomicLVal.getTBAAInfo()); 1931 } 1932 // Store new value in the corresponding memory area. 1933 assert(UpdateRVal.isScalar()); 1934 CGF.EmitStoreThroughLValue(UpdateRVal, DesiredLVal); 1935 } 1936 1937 void AtomicInfo::EmitAtomicUpdateLibcall(llvm::AtomicOrdering AO, 1938 RValue UpdateRVal, bool IsVolatile) { 1939 auto Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(AO); 1940 1941 Address ExpectedAddr = CreateTempAlloca(); 1942 1943 EmitAtomicLoadLibcall(ExpectedAddr.getPointer(), AO, IsVolatile); 1944 auto *ContBB = CGF.createBasicBlock("atomic_cont"); 1945 auto *ExitBB = CGF.createBasicBlock("atomic_exit"); 1946 CGF.EmitBlock(ContBB); 1947 Address DesiredAddr = CreateTempAlloca(); 1948 if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) || 1949 requiresMemSetZero(getAtomicAddress().getElementType())) { 1950 auto *OldVal = CGF.Builder.CreateLoad(ExpectedAddr); 1951 CGF.Builder.CreateStore(OldVal, DesiredAddr); 1952 } 1953 EmitAtomicUpdateValue(CGF, *this, UpdateRVal, DesiredAddr); 1954 auto *Res = 1955 EmitAtomicCompareExchangeLibcall(ExpectedAddr.getPointer(), 1956 DesiredAddr.getPointer(), 1957 AO, Failure); 1958 CGF.Builder.CreateCondBr(Res, ExitBB, ContBB); 1959 CGF.EmitBlock(ExitBB, /*IsFinished=*/true); 1960 } 1961 1962 void AtomicInfo::EmitAtomicUpdateOp(llvm::AtomicOrdering AO, RValue UpdateRVal, 1963 bool IsVolatile) { 1964 auto Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(AO); 1965 1966 // Do the atomic load. 1967 auto *OldVal = EmitAtomicLoadOp(Failure, IsVolatile); 1968 // For non-simple lvalues perform compare-and-swap procedure. 1969 auto *ContBB = CGF.createBasicBlock("atomic_cont"); 1970 auto *ExitBB = CGF.createBasicBlock("atomic_exit"); 1971 auto *CurBB = CGF.Builder.GetInsertBlock(); 1972 CGF.EmitBlock(ContBB); 1973 llvm::PHINode *PHI = CGF.Builder.CreatePHI(OldVal->getType(), 1974 /*NumReservedValues=*/2); 1975 PHI->addIncoming(OldVal, CurBB); 1976 Address NewAtomicAddr = CreateTempAlloca(); 1977 Address NewAtomicIntAddr = emitCastToAtomicIntPointer(NewAtomicAddr); 1978 if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) || 1979 requiresMemSetZero(getAtomicAddress().getElementType())) { 1980 CGF.Builder.CreateStore(PHI, NewAtomicIntAddr); 1981 } 1982 EmitAtomicUpdateValue(CGF, *this, UpdateRVal, NewAtomicAddr); 1983 auto *DesiredVal = CGF.Builder.CreateLoad(NewAtomicIntAddr); 1984 // Try to write new value using cmpxchg operation. 1985 auto Res = EmitAtomicCompareExchangeOp(PHI, DesiredVal, AO, Failure); 1986 PHI->addIncoming(Res.first, CGF.Builder.GetInsertBlock()); 1987 CGF.Builder.CreateCondBr(Res.second, ExitBB, ContBB); 1988 CGF.EmitBlock(ExitBB, /*IsFinished=*/true); 1989 } 1990 1991 void AtomicInfo::EmitAtomicUpdate( 1992 llvm::AtomicOrdering AO, const llvm::function_ref<RValue(RValue)> &UpdateOp, 1993 bool IsVolatile) { 1994 if (shouldUseLibcall()) { 1995 EmitAtomicUpdateLibcall(AO, UpdateOp, IsVolatile); 1996 } else { 1997 EmitAtomicUpdateOp(AO, UpdateOp, IsVolatile); 1998 } 1999 } 2000 2001 void AtomicInfo::EmitAtomicUpdate(llvm::AtomicOrdering AO, RValue UpdateRVal, 2002 bool IsVolatile) { 2003 if (shouldUseLibcall()) { 2004 EmitAtomicUpdateLibcall(AO, UpdateRVal, IsVolatile); 2005 } else { 2006 EmitAtomicUpdateOp(AO, UpdateRVal, IsVolatile); 2007 } 2008 } 2009 2010 void CodeGenFunction::EmitAtomicStore(RValue rvalue, LValue lvalue, 2011 bool isInit) { 2012 bool IsVolatile = lvalue.isVolatileQualified(); 2013 llvm::AtomicOrdering AO; 2014 if (lvalue.getType()->isAtomicType()) { 2015 AO = llvm::AtomicOrdering::SequentiallyConsistent; 2016 } else { 2017 AO = llvm::AtomicOrdering::Release; 2018 IsVolatile = true; 2019 } 2020 return EmitAtomicStore(rvalue, lvalue, AO, IsVolatile, isInit); 2021 } 2022 2023 /// Emit a store to an l-value of atomic type. 2024 /// 2025 /// Note that the r-value is expected to be an r-value *of the atomic 2026 /// type*; this means that for aggregate r-values, it should include 2027 /// storage for any padding that was necessary. 2028 void CodeGenFunction::EmitAtomicStore(RValue rvalue, LValue dest, 2029 llvm::AtomicOrdering AO, bool IsVolatile, 2030 bool isInit) { 2031 // If this is an aggregate r-value, it should agree in type except 2032 // maybe for address-space qualification. 2033 assert(!rvalue.isAggregate() || 2034 rvalue.getAggregateAddress().getElementType() == 2035 dest.getAddress(*this).getElementType()); 2036 2037 AtomicInfo atomics(*this, dest); 2038 LValue LVal = atomics.getAtomicLValue(); 2039 2040 // If this is an initialization, just put the value there normally. 2041 if (LVal.isSimple()) { 2042 if (isInit) { 2043 atomics.emitCopyIntoMemory(rvalue); 2044 return; 2045 } 2046 2047 // Check whether we should use a library call. 2048 if (atomics.shouldUseLibcall()) { 2049 // Produce a source address. 2050 Address srcAddr = atomics.materializeRValue(rvalue); 2051 2052 // void __atomic_store(size_t size, void *mem, void *val, int order) 2053 CallArgList args; 2054 args.add(RValue::get(atomics.getAtomicSizeValue()), 2055 getContext().getSizeType()); 2056 args.add(RValue::get(EmitCastToVoidPtr(atomics.getAtomicPointer())), 2057 getContext().VoidPtrTy); 2058 args.add(RValue::get(EmitCastToVoidPtr(srcAddr.getPointer())), 2059 getContext().VoidPtrTy); 2060 args.add( 2061 RValue::get(llvm::ConstantInt::get(IntTy, (int)llvm::toCABI(AO))), 2062 getContext().IntTy); 2063 emitAtomicLibcall(*this, "__atomic_store", getContext().VoidTy, args); 2064 return; 2065 } 2066 2067 // Okay, we're doing this natively. 2068 llvm::Value *intValue = atomics.convertRValueToInt(rvalue); 2069 2070 // Do the atomic store. 2071 Address addr = 2072 atomics.emitCastToAtomicIntPointer(atomics.getAtomicAddress()); 2073 intValue = Builder.CreateIntCast( 2074 intValue, addr.getElementType(), /*isSigned=*/false); 2075 llvm::StoreInst *store = Builder.CreateStore(intValue, addr); 2076 2077 if (AO == llvm::AtomicOrdering::Acquire) 2078 AO = llvm::AtomicOrdering::Monotonic; 2079 else if (AO == llvm::AtomicOrdering::AcquireRelease) 2080 AO = llvm::AtomicOrdering::Release; 2081 // Initializations don't need to be atomic. 2082 if (!isInit) 2083 store->setAtomic(AO); 2084 2085 // Other decoration. 2086 if (IsVolatile) 2087 store->setVolatile(true); 2088 CGM.DecorateInstructionWithTBAA(store, dest.getTBAAInfo()); 2089 return; 2090 } 2091 2092 // Emit simple atomic update operation. 2093 atomics.EmitAtomicUpdate(AO, rvalue, IsVolatile); 2094 } 2095 2096 /// Emit a compare-and-exchange op for atomic type. 2097 /// 2098 std::pair<RValue, llvm::Value *> CodeGenFunction::EmitAtomicCompareExchange( 2099 LValue Obj, RValue Expected, RValue Desired, SourceLocation Loc, 2100 llvm::AtomicOrdering Success, llvm::AtomicOrdering Failure, bool IsWeak, 2101 AggValueSlot Slot) { 2102 // If this is an aggregate r-value, it should agree in type except 2103 // maybe for address-space qualification. 2104 assert(!Expected.isAggregate() || 2105 Expected.getAggregateAddress().getElementType() == 2106 Obj.getAddress(*this).getElementType()); 2107 assert(!Desired.isAggregate() || 2108 Desired.getAggregateAddress().getElementType() == 2109 Obj.getAddress(*this).getElementType()); 2110 AtomicInfo Atomics(*this, Obj); 2111 2112 return Atomics.EmitAtomicCompareExchange(Expected, Desired, Success, Failure, 2113 IsWeak); 2114 } 2115 2116 void CodeGenFunction::EmitAtomicUpdate( 2117 LValue LVal, llvm::AtomicOrdering AO, 2118 const llvm::function_ref<RValue(RValue)> &UpdateOp, bool IsVolatile) { 2119 AtomicInfo Atomics(*this, LVal); 2120 Atomics.EmitAtomicUpdate(AO, UpdateOp, IsVolatile); 2121 } 2122 2123 void CodeGenFunction::EmitAtomicInit(Expr *init, LValue dest) { 2124 AtomicInfo atomics(*this, dest); 2125 2126 switch (atomics.getEvaluationKind()) { 2127 case TEK_Scalar: { 2128 llvm::Value *value = EmitScalarExpr(init); 2129 atomics.emitCopyIntoMemory(RValue::get(value)); 2130 return; 2131 } 2132 2133 case TEK_Complex: { 2134 ComplexPairTy value = EmitComplexExpr(init); 2135 atomics.emitCopyIntoMemory(RValue::getComplex(value)); 2136 return; 2137 } 2138 2139 case TEK_Aggregate: { 2140 // Fix up the destination if the initializer isn't an expression 2141 // of atomic type. 2142 bool Zeroed = false; 2143 if (!init->getType()->isAtomicType()) { 2144 Zeroed = atomics.emitMemSetZeroIfNecessary(); 2145 dest = atomics.projectValue(); 2146 } 2147 2148 // Evaluate the expression directly into the destination. 2149 AggValueSlot slot = AggValueSlot::forLValue( 2150 dest, *this, AggValueSlot::IsNotDestructed, 2151 AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased, 2152 AggValueSlot::DoesNotOverlap, 2153 Zeroed ? AggValueSlot::IsZeroed : AggValueSlot::IsNotZeroed); 2154 2155 EmitAggExpr(init, slot); 2156 return; 2157 } 2158 } 2159 llvm_unreachable("bad evaluation kind"); 2160 } 2161