1 //===--- CGStmtOpenMP.cpp - Emit LLVM Code from Statements ----------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This contains code to emit OpenMP nodes as LLVM code.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CGOpenMPRuntime.h"
15 #include "CodeGenFunction.h"
16 #include "CodeGenModule.h"
17 #include "TargetInfo.h"
18 #include "clang/AST/Stmt.h"
19 #include "clang/AST/StmtOpenMP.h"
20 using namespace clang;
21 using namespace CodeGen;
22 
23 void CodeGenFunction::GenerateOpenMPCapturedVars(
24     const CapturedStmt &S, SmallVectorImpl<llvm::Value *> &CapturedVars) {
25   const RecordDecl *RD = S.getCapturedRecordDecl();
26   auto CurField = RD->field_begin();
27   auto CurCap = S.captures().begin();
28   for (CapturedStmt::const_capture_init_iterator I = S.capture_init_begin(),
29                                                  E = S.capture_init_end();
30        I != E; ++I, ++CurField, ++CurCap) {
31     if (CurField->hasCapturedVLAType()) {
32       auto VAT = CurField->getCapturedVLAType();
33       auto *Val = VLASizeMap[VAT->getSizeExpr()];
34       CapturedVars.push_back(Val);
35     } else if (CurCap->capturesThis())
36       CapturedVars.push_back(CXXThisValue);
37     else if (CurCap->capturesVariableByCopy())
38       CapturedVars.push_back(
39           EmitLoadOfLValue(EmitLValue(*I), SourceLocation()).getScalarVal());
40     else {
41       assert(CurCap->capturesVariable() && "Expected capture by reference.");
42       CapturedVars.push_back(EmitLValue(*I).getAddress().getPointer());
43     }
44   }
45 }
46 
47 static Address castValueFromUintptr(CodeGenFunction &CGF, QualType DstType,
48                                     StringRef Name, LValue AddrLV,
49                                     bool isReferenceType = false) {
50   ASTContext &Ctx = CGF.getContext();
51 
52   auto *CastedPtr = CGF.EmitScalarConversion(
53       AddrLV.getAddress().getPointer(), Ctx.getUIntPtrType(),
54       Ctx.getPointerType(DstType), SourceLocation());
55   auto TmpAddr =
56       CGF.MakeNaturalAlignAddrLValue(CastedPtr, Ctx.getPointerType(DstType))
57           .getAddress();
58 
59   // If we are dealing with references we need to return the address of the
60   // reference instead of the reference of the value.
61   if (isReferenceType) {
62     QualType RefType = Ctx.getLValueReferenceType(DstType);
63     auto *RefVal = TmpAddr.getPointer();
64     TmpAddr = CGF.CreateMemTemp(RefType, Twine(Name) + ".ref");
65     auto TmpLVal = CGF.MakeAddrLValue(TmpAddr, RefType);
66     CGF.EmitScalarInit(RefVal, TmpLVal);
67   }
68 
69   return TmpAddr;
70 }
71 
72 llvm::Function *
73 CodeGenFunction::GenerateOpenMPCapturedStmtFunction(const CapturedStmt &S) {
74   assert(
75       CapturedStmtInfo &&
76       "CapturedStmtInfo should be set when generating the captured function");
77   const CapturedDecl *CD = S.getCapturedDecl();
78   const RecordDecl *RD = S.getCapturedRecordDecl();
79   assert(CD->hasBody() && "missing CapturedDecl body");
80 
81   // Build the argument list.
82   ASTContext &Ctx = CGM.getContext();
83   FunctionArgList Args;
84   Args.append(CD->param_begin(),
85               std::next(CD->param_begin(), CD->getContextParamPosition()));
86   auto I = S.captures().begin();
87   for (auto *FD : RD->fields()) {
88     QualType ArgType = FD->getType();
89     IdentifierInfo *II = nullptr;
90     VarDecl *CapVar = nullptr;
91 
92     // If this is a capture by copy and the type is not a pointer, the outlined
93     // function argument type should be uintptr and the value properly casted to
94     // uintptr. This is necessary given that the runtime library is only able to
95     // deal with pointers. We can pass in the same way the VLA type sizes to the
96     // outlined function.
97     if ((I->capturesVariableByCopy() && !ArgType->isAnyPointerType()) ||
98         I->capturesVariableArrayType())
99       ArgType = Ctx.getUIntPtrType();
100 
101     if (I->capturesVariable() || I->capturesVariableByCopy()) {
102       CapVar = I->getCapturedVar();
103       II = CapVar->getIdentifier();
104     } else if (I->capturesThis())
105       II = &getContext().Idents.get("this");
106     else {
107       assert(I->capturesVariableArrayType());
108       II = &getContext().Idents.get("vla");
109     }
110     if (ArgType->isVariablyModifiedType())
111       ArgType = getContext().getVariableArrayDecayedType(ArgType);
112     Args.push_back(ImplicitParamDecl::Create(getContext(), nullptr,
113                                              FD->getLocation(), II, ArgType));
114     ++I;
115   }
116   Args.append(
117       std::next(CD->param_begin(), CD->getContextParamPosition() + 1),
118       CD->param_end());
119 
120   // Create the function declaration.
121   FunctionType::ExtInfo ExtInfo;
122   const CGFunctionInfo &FuncInfo =
123       CGM.getTypes().arrangeFreeFunctionDeclaration(Ctx.VoidTy, Args, ExtInfo,
124                                                     /*IsVariadic=*/false);
125   llvm::FunctionType *FuncLLVMTy = CGM.getTypes().GetFunctionType(FuncInfo);
126 
127   llvm::Function *F = llvm::Function::Create(
128       FuncLLVMTy, llvm::GlobalValue::InternalLinkage,
129       CapturedStmtInfo->getHelperName(), &CGM.getModule());
130   CGM.SetInternalFunctionAttributes(CD, F, FuncInfo);
131   if (CD->isNothrow())
132     F->addFnAttr(llvm::Attribute::NoUnwind);
133 
134   // Generate the function.
135   StartFunction(CD, Ctx.VoidTy, F, FuncInfo, Args, CD->getLocation(),
136                 CD->getBody()->getLocStart());
137   unsigned Cnt = CD->getContextParamPosition();
138   I = S.captures().begin();
139   for (auto *FD : RD->fields()) {
140     // If we are capturing a pointer by copy we don't need to do anything, just
141     // use the value that we get from the arguments.
142     if (I->capturesVariableByCopy() && FD->getType()->isAnyPointerType()) {
143       setAddrOfLocalVar(I->getCapturedVar(), GetAddrOfLocalVar(Args[Cnt]));
144       ++Cnt, ++I;
145       continue;
146     }
147 
148     LValue ArgLVal =
149         MakeAddrLValue(GetAddrOfLocalVar(Args[Cnt]), Args[Cnt]->getType(),
150                        AlignmentSource::Decl);
151     if (FD->hasCapturedVLAType()) {
152       LValue CastedArgLVal =
153           MakeAddrLValue(castValueFromUintptr(*this, FD->getType(),
154                                               Args[Cnt]->getName(), ArgLVal),
155                          FD->getType(), AlignmentSource::Decl);
156       auto *ExprArg =
157           EmitLoadOfLValue(CastedArgLVal, SourceLocation()).getScalarVal();
158       auto VAT = FD->getCapturedVLAType();
159       VLASizeMap[VAT->getSizeExpr()] = ExprArg;
160     } else if (I->capturesVariable()) {
161       auto *Var = I->getCapturedVar();
162       QualType VarTy = Var->getType();
163       Address ArgAddr = ArgLVal.getAddress();
164       if (!VarTy->isReferenceType()) {
165         ArgAddr = EmitLoadOfReference(
166             ArgAddr, ArgLVal.getType()->castAs<ReferenceType>());
167       }
168       setAddrOfLocalVar(
169           Var, Address(ArgAddr.getPointer(), getContext().getDeclAlign(Var)));
170     } else if (I->capturesVariableByCopy()) {
171       assert(!FD->getType()->isAnyPointerType() &&
172              "Not expecting a captured pointer.");
173       auto *Var = I->getCapturedVar();
174       QualType VarTy = Var->getType();
175       setAddrOfLocalVar(I->getCapturedVar(),
176                         castValueFromUintptr(*this, FD->getType(),
177                                              Args[Cnt]->getName(), ArgLVal,
178                                              VarTy->isReferenceType()));
179     } else {
180       // If 'this' is captured, load it into CXXThisValue.
181       assert(I->capturesThis());
182       CXXThisValue =
183           EmitLoadOfLValue(ArgLVal, Args[Cnt]->getLocation()).getScalarVal();
184     }
185     ++Cnt, ++I;
186   }
187 
188   PGO.assignRegionCounters(GlobalDecl(CD), F);
189   CapturedStmtInfo->EmitBody(*this, CD->getBody());
190   FinishFunction(CD->getBodyRBrace());
191 
192   return F;
193 }
194 
195 //===----------------------------------------------------------------------===//
196 //                              OpenMP Directive Emission
197 //===----------------------------------------------------------------------===//
198 void CodeGenFunction::EmitOMPAggregateAssign(
199     Address DestAddr, Address SrcAddr, QualType OriginalType,
200     const llvm::function_ref<void(Address, Address)> &CopyGen) {
201   // Perform element-by-element initialization.
202   QualType ElementTy;
203 
204   // Drill down to the base element type on both arrays.
205   auto ArrayTy = OriginalType->getAsArrayTypeUnsafe();
206   auto NumElements = emitArrayLength(ArrayTy, ElementTy, DestAddr);
207   SrcAddr = Builder.CreateElementBitCast(SrcAddr, DestAddr.getElementType());
208 
209   auto SrcBegin = SrcAddr.getPointer();
210   auto DestBegin = DestAddr.getPointer();
211   // Cast from pointer to array type to pointer to single element.
212   auto DestEnd = Builder.CreateGEP(DestBegin, NumElements);
213   // The basic structure here is a while-do loop.
214   auto BodyBB = createBasicBlock("omp.arraycpy.body");
215   auto DoneBB = createBasicBlock("omp.arraycpy.done");
216   auto IsEmpty =
217       Builder.CreateICmpEQ(DestBegin, DestEnd, "omp.arraycpy.isempty");
218   Builder.CreateCondBr(IsEmpty, DoneBB, BodyBB);
219 
220   // Enter the loop body, making that address the current address.
221   auto EntryBB = Builder.GetInsertBlock();
222   EmitBlock(BodyBB);
223 
224   CharUnits ElementSize = getContext().getTypeSizeInChars(ElementTy);
225 
226   llvm::PHINode *SrcElementPHI =
227     Builder.CreatePHI(SrcBegin->getType(), 2, "omp.arraycpy.srcElementPast");
228   SrcElementPHI->addIncoming(SrcBegin, EntryBB);
229   Address SrcElementCurrent =
230       Address(SrcElementPHI,
231               SrcAddr.getAlignment().alignmentOfArrayElement(ElementSize));
232 
233   llvm::PHINode *DestElementPHI =
234     Builder.CreatePHI(DestBegin->getType(), 2, "omp.arraycpy.destElementPast");
235   DestElementPHI->addIncoming(DestBegin, EntryBB);
236   Address DestElementCurrent =
237     Address(DestElementPHI,
238             DestAddr.getAlignment().alignmentOfArrayElement(ElementSize));
239 
240   // Emit copy.
241   CopyGen(DestElementCurrent, SrcElementCurrent);
242 
243   // Shift the address forward by one element.
244   auto DestElementNext = Builder.CreateConstGEP1_32(
245       DestElementPHI, /*Idx0=*/1, "omp.arraycpy.dest.element");
246   auto SrcElementNext = Builder.CreateConstGEP1_32(
247       SrcElementPHI, /*Idx0=*/1, "omp.arraycpy.src.element");
248   // Check whether we've reached the end.
249   auto Done =
250       Builder.CreateICmpEQ(DestElementNext, DestEnd, "omp.arraycpy.done");
251   Builder.CreateCondBr(Done, DoneBB, BodyBB);
252   DestElementPHI->addIncoming(DestElementNext, Builder.GetInsertBlock());
253   SrcElementPHI->addIncoming(SrcElementNext, Builder.GetInsertBlock());
254 
255   // Done.
256   EmitBlock(DoneBB, /*IsFinished=*/true);
257 }
258 
259 /// \brief Emit initialization of arrays of complex types.
260 /// \param DestAddr Address of the array.
261 /// \param Type Type of array.
262 /// \param Init Initial expression of array.
263 static void EmitOMPAggregateInit(CodeGenFunction &CGF, Address DestAddr,
264                                  QualType Type, const Expr *Init) {
265   // Perform element-by-element initialization.
266   QualType ElementTy;
267 
268   // Drill down to the base element type on both arrays.
269   auto ArrayTy = Type->getAsArrayTypeUnsafe();
270   auto NumElements = CGF.emitArrayLength(ArrayTy, ElementTy, DestAddr);
271   DestAddr =
272       CGF.Builder.CreateElementBitCast(DestAddr, DestAddr.getElementType());
273 
274   auto DestBegin = DestAddr.getPointer();
275   // Cast from pointer to array type to pointer to single element.
276   auto DestEnd = CGF.Builder.CreateGEP(DestBegin, NumElements);
277   // The basic structure here is a while-do loop.
278   auto BodyBB = CGF.createBasicBlock("omp.arrayinit.body");
279   auto DoneBB = CGF.createBasicBlock("omp.arrayinit.done");
280   auto IsEmpty =
281       CGF.Builder.CreateICmpEQ(DestBegin, DestEnd, "omp.arrayinit.isempty");
282   CGF.Builder.CreateCondBr(IsEmpty, DoneBB, BodyBB);
283 
284   // Enter the loop body, making that address the current address.
285   auto EntryBB = CGF.Builder.GetInsertBlock();
286   CGF.EmitBlock(BodyBB);
287 
288   CharUnits ElementSize = CGF.getContext().getTypeSizeInChars(ElementTy);
289 
290   llvm::PHINode *DestElementPHI = CGF.Builder.CreatePHI(
291       DestBegin->getType(), 2, "omp.arraycpy.destElementPast");
292   DestElementPHI->addIncoming(DestBegin, EntryBB);
293   Address DestElementCurrent =
294       Address(DestElementPHI,
295               DestAddr.getAlignment().alignmentOfArrayElement(ElementSize));
296 
297   // Emit copy.
298   {
299     CodeGenFunction::RunCleanupsScope InitScope(CGF);
300     CGF.EmitAnyExprToMem(Init, DestElementCurrent, ElementTy.getQualifiers(),
301                          /*IsInitializer=*/false);
302   }
303 
304   // Shift the address forward by one element.
305   auto DestElementNext = CGF.Builder.CreateConstGEP1_32(
306       DestElementPHI, /*Idx0=*/1, "omp.arraycpy.dest.element");
307   // Check whether we've reached the end.
308   auto Done =
309       CGF.Builder.CreateICmpEQ(DestElementNext, DestEnd, "omp.arraycpy.done");
310   CGF.Builder.CreateCondBr(Done, DoneBB, BodyBB);
311   DestElementPHI->addIncoming(DestElementNext, CGF.Builder.GetInsertBlock());
312 
313   // Done.
314   CGF.EmitBlock(DoneBB, /*IsFinished=*/true);
315 }
316 
317 void CodeGenFunction::EmitOMPCopy(QualType OriginalType, Address DestAddr,
318                                   Address SrcAddr, const VarDecl *DestVD,
319                                   const VarDecl *SrcVD, const Expr *Copy) {
320   if (OriginalType->isArrayType()) {
321     auto *BO = dyn_cast<BinaryOperator>(Copy);
322     if (BO && BO->getOpcode() == BO_Assign) {
323       // Perform simple memcpy for simple copying.
324       EmitAggregateAssign(DestAddr, SrcAddr, OriginalType);
325     } else {
326       // For arrays with complex element types perform element by element
327       // copying.
328       EmitOMPAggregateAssign(
329           DestAddr, SrcAddr, OriginalType,
330           [this, Copy, SrcVD, DestVD](Address DestElement, Address SrcElement) {
331             // Working with the single array element, so have to remap
332             // destination and source variables to corresponding array
333             // elements.
334             CodeGenFunction::OMPPrivateScope Remap(*this);
335             Remap.addPrivate(DestVD, [DestElement]() -> Address {
336               return DestElement;
337             });
338             Remap.addPrivate(
339                 SrcVD, [SrcElement]() -> Address { return SrcElement; });
340             (void)Remap.Privatize();
341             EmitIgnoredExpr(Copy);
342           });
343     }
344   } else {
345     // Remap pseudo source variable to private copy.
346     CodeGenFunction::OMPPrivateScope Remap(*this);
347     Remap.addPrivate(SrcVD, [SrcAddr]() -> Address { return SrcAddr; });
348     Remap.addPrivate(DestVD, [DestAddr]() -> Address { return DestAddr; });
349     (void)Remap.Privatize();
350     // Emit copying of the whole variable.
351     EmitIgnoredExpr(Copy);
352   }
353 }
354 
355 bool CodeGenFunction::EmitOMPFirstprivateClause(const OMPExecutableDirective &D,
356                                                 OMPPrivateScope &PrivateScope) {
357   if (!HaveInsertPoint())
358     return false;
359   llvm::DenseSet<const VarDecl *> EmittedAsFirstprivate;
360   for (const auto *C : D.getClausesOfKind<OMPFirstprivateClause>()) {
361     auto IRef = C->varlist_begin();
362     auto InitsRef = C->inits().begin();
363     for (auto IInit : C->private_copies()) {
364       auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
365       if (EmittedAsFirstprivate.count(OrigVD) == 0) {
366         EmittedAsFirstprivate.insert(OrigVD);
367         auto *VD = cast<VarDecl>(cast<DeclRefExpr>(IInit)->getDecl());
368         auto *VDInit = cast<VarDecl>(cast<DeclRefExpr>(*InitsRef)->getDecl());
369         bool IsRegistered;
370         DeclRefExpr DRE(
371             const_cast<VarDecl *>(OrigVD),
372             /*RefersToEnclosingVariableOrCapture=*/CapturedStmtInfo->lookup(
373                 OrigVD) != nullptr,
374             (*IRef)->getType(), VK_LValue, (*IRef)->getExprLoc());
375         Address OriginalAddr = EmitLValue(&DRE).getAddress();
376         QualType Type = OrigVD->getType();
377         if (Type->isArrayType()) {
378           // Emit VarDecl with copy init for arrays.
379           // Get the address of the original variable captured in current
380           // captured region.
381           IsRegistered = PrivateScope.addPrivate(OrigVD, [&]() -> Address {
382             auto Emission = EmitAutoVarAlloca(*VD);
383             auto *Init = VD->getInit();
384             if (!isa<CXXConstructExpr>(Init) || isTrivialInitializer(Init)) {
385               // Perform simple memcpy.
386               EmitAggregateAssign(Emission.getAllocatedAddress(), OriginalAddr,
387                                   Type);
388             } else {
389               EmitOMPAggregateAssign(
390                   Emission.getAllocatedAddress(), OriginalAddr, Type,
391                   [this, VDInit, Init](Address DestElement,
392                                        Address SrcElement) {
393                     // Clean up any temporaries needed by the initialization.
394                     RunCleanupsScope InitScope(*this);
395                     // Emit initialization for single element.
396                     setAddrOfLocalVar(VDInit, SrcElement);
397                     EmitAnyExprToMem(Init, DestElement,
398                                      Init->getType().getQualifiers(),
399                                      /*IsInitializer*/ false);
400                     LocalDeclMap.erase(VDInit);
401                   });
402             }
403             EmitAutoVarCleanups(Emission);
404             return Emission.getAllocatedAddress();
405           });
406         } else {
407           IsRegistered = PrivateScope.addPrivate(OrigVD, [&]() -> Address {
408             // Emit private VarDecl with copy init.
409             // Remap temp VDInit variable to the address of the original
410             // variable
411             // (for proper handling of captured global variables).
412             setAddrOfLocalVar(VDInit, OriginalAddr);
413             EmitDecl(*VD);
414             LocalDeclMap.erase(VDInit);
415             return GetAddrOfLocalVar(VD);
416           });
417         }
418         assert(IsRegistered &&
419                "firstprivate var already registered as private");
420         // Silence the warning about unused variable.
421         (void)IsRegistered;
422       }
423       ++IRef, ++InitsRef;
424     }
425   }
426   return !EmittedAsFirstprivate.empty();
427 }
428 
429 void CodeGenFunction::EmitOMPPrivateClause(
430     const OMPExecutableDirective &D,
431     CodeGenFunction::OMPPrivateScope &PrivateScope) {
432   if (!HaveInsertPoint())
433     return;
434   llvm::DenseSet<const VarDecl *> EmittedAsPrivate;
435   for (const auto *C : D.getClausesOfKind<OMPPrivateClause>()) {
436     auto IRef = C->varlist_begin();
437     for (auto IInit : C->private_copies()) {
438       auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
439       if (EmittedAsPrivate.insert(OrigVD->getCanonicalDecl()).second) {
440         auto VD = cast<VarDecl>(cast<DeclRefExpr>(IInit)->getDecl());
441         bool IsRegistered =
442             PrivateScope.addPrivate(OrigVD, [&]() -> Address {
443               // Emit private VarDecl with copy init.
444               EmitDecl(*VD);
445               return GetAddrOfLocalVar(VD);
446             });
447         assert(IsRegistered && "private var already registered as private");
448         // Silence the warning about unused variable.
449         (void)IsRegistered;
450       }
451       ++IRef;
452     }
453   }
454 }
455 
456 bool CodeGenFunction::EmitOMPCopyinClause(const OMPExecutableDirective &D) {
457   if (!HaveInsertPoint())
458     return false;
459   // threadprivate_var1 = master_threadprivate_var1;
460   // operator=(threadprivate_var2, master_threadprivate_var2);
461   // ...
462   // __kmpc_barrier(&loc, global_tid);
463   llvm::DenseSet<const VarDecl *> CopiedVars;
464   llvm::BasicBlock *CopyBegin = nullptr, *CopyEnd = nullptr;
465   for (const auto *C : D.getClausesOfKind<OMPCopyinClause>()) {
466     auto IRef = C->varlist_begin();
467     auto ISrcRef = C->source_exprs().begin();
468     auto IDestRef = C->destination_exprs().begin();
469     for (auto *AssignOp : C->assignment_ops()) {
470       auto *VD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
471       QualType Type = VD->getType();
472       if (CopiedVars.insert(VD->getCanonicalDecl()).second) {
473 
474         // Get the address of the master variable. If we are emitting code with
475         // TLS support, the address is passed from the master as field in the
476         // captured declaration.
477         Address MasterAddr = Address::invalid();
478         if (getLangOpts().OpenMPUseTLS &&
479             getContext().getTargetInfo().isTLSSupported()) {
480           assert(CapturedStmtInfo->lookup(VD) &&
481                  "Copyin threadprivates should have been captured!");
482           DeclRefExpr DRE(const_cast<VarDecl *>(VD), true, (*IRef)->getType(),
483                           VK_LValue, (*IRef)->getExprLoc());
484           MasterAddr = EmitLValue(&DRE).getAddress();
485           LocalDeclMap.erase(VD);
486         } else {
487           MasterAddr =
488             Address(VD->isStaticLocal() ? CGM.getStaticLocalDeclAddress(VD)
489                                         : CGM.GetAddrOfGlobal(VD),
490                     getContext().getDeclAlign(VD));
491         }
492         // Get the address of the threadprivate variable.
493         Address PrivateAddr = EmitLValue(*IRef).getAddress();
494         if (CopiedVars.size() == 1) {
495           // At first check if current thread is a master thread. If it is, no
496           // need to copy data.
497           CopyBegin = createBasicBlock("copyin.not.master");
498           CopyEnd = createBasicBlock("copyin.not.master.end");
499           Builder.CreateCondBr(
500               Builder.CreateICmpNE(
501                   Builder.CreatePtrToInt(MasterAddr.getPointer(), CGM.IntPtrTy),
502                   Builder.CreatePtrToInt(PrivateAddr.getPointer(), CGM.IntPtrTy)),
503               CopyBegin, CopyEnd);
504           EmitBlock(CopyBegin);
505         }
506         auto *SrcVD = cast<VarDecl>(cast<DeclRefExpr>(*ISrcRef)->getDecl());
507         auto *DestVD = cast<VarDecl>(cast<DeclRefExpr>(*IDestRef)->getDecl());
508         EmitOMPCopy(Type, PrivateAddr, MasterAddr, DestVD, SrcVD, AssignOp);
509       }
510       ++IRef;
511       ++ISrcRef;
512       ++IDestRef;
513     }
514   }
515   if (CopyEnd) {
516     // Exit out of copying procedure for non-master thread.
517     EmitBlock(CopyEnd, /*IsFinished=*/true);
518     return true;
519   }
520   return false;
521 }
522 
523 bool CodeGenFunction::EmitOMPLastprivateClauseInit(
524     const OMPExecutableDirective &D, OMPPrivateScope &PrivateScope) {
525   if (!HaveInsertPoint())
526     return false;
527   bool HasAtLeastOneLastprivate = false;
528   llvm::DenseSet<const VarDecl *> AlreadyEmittedVars;
529   for (const auto *C : D.getClausesOfKind<OMPLastprivateClause>()) {
530     HasAtLeastOneLastprivate = true;
531     auto IRef = C->varlist_begin();
532     auto IDestRef = C->destination_exprs().begin();
533     for (auto *IInit : C->private_copies()) {
534       // Keep the address of the original variable for future update at the end
535       // of the loop.
536       auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
537       if (AlreadyEmittedVars.insert(OrigVD->getCanonicalDecl()).second) {
538         auto *DestVD = cast<VarDecl>(cast<DeclRefExpr>(*IDestRef)->getDecl());
539         PrivateScope.addPrivate(DestVD, [this, OrigVD, IRef]() -> Address {
540           DeclRefExpr DRE(
541               const_cast<VarDecl *>(OrigVD),
542               /*RefersToEnclosingVariableOrCapture=*/CapturedStmtInfo->lookup(
543                   OrigVD) != nullptr,
544               (*IRef)->getType(), VK_LValue, (*IRef)->getExprLoc());
545           return EmitLValue(&DRE).getAddress();
546         });
547         // Check if the variable is also a firstprivate: in this case IInit is
548         // not generated. Initialization of this variable will happen in codegen
549         // for 'firstprivate' clause.
550         if (IInit) {
551           auto *VD = cast<VarDecl>(cast<DeclRefExpr>(IInit)->getDecl());
552           bool IsRegistered =
553               PrivateScope.addPrivate(OrigVD, [&]() -> Address {
554                 // Emit private VarDecl with copy init.
555                 EmitDecl(*VD);
556                 return GetAddrOfLocalVar(VD);
557               });
558           assert(IsRegistered &&
559                  "lastprivate var already registered as private");
560           (void)IsRegistered;
561         }
562       }
563       ++IRef, ++IDestRef;
564     }
565   }
566   return HasAtLeastOneLastprivate;
567 }
568 
569 void CodeGenFunction::EmitOMPLastprivateClauseFinal(
570     const OMPExecutableDirective &D, llvm::Value *IsLastIterCond) {
571   if (!HaveInsertPoint())
572     return;
573   // Emit following code:
574   // if (<IsLastIterCond>) {
575   //   orig_var1 = private_orig_var1;
576   //   ...
577   //   orig_varn = private_orig_varn;
578   // }
579   llvm::BasicBlock *ThenBB = nullptr;
580   llvm::BasicBlock *DoneBB = nullptr;
581   if (IsLastIterCond) {
582     ThenBB = createBasicBlock(".omp.lastprivate.then");
583     DoneBB = createBasicBlock(".omp.lastprivate.done");
584     Builder.CreateCondBr(IsLastIterCond, ThenBB, DoneBB);
585     EmitBlock(ThenBB);
586   }
587   llvm::DenseMap<const Decl *, const Expr *> LoopCountersAndUpdates;
588   const Expr *LastIterVal = nullptr;
589   const Expr *IVExpr = nullptr;
590   const Expr *IncExpr = nullptr;
591   if (auto *LoopDirective = dyn_cast<OMPLoopDirective>(&D)) {
592     if (isOpenMPWorksharingDirective(D.getDirectiveKind())) {
593       LastIterVal = cast<VarDecl>(cast<DeclRefExpr>(
594                                       LoopDirective->getUpperBoundVariable())
595                                       ->getDecl())
596                         ->getAnyInitializer();
597       IVExpr = LoopDirective->getIterationVariable();
598       IncExpr = LoopDirective->getInc();
599       auto IUpdate = LoopDirective->updates().begin();
600       for (auto *E : LoopDirective->counters()) {
601         auto *D = cast<DeclRefExpr>(E)->getDecl()->getCanonicalDecl();
602         LoopCountersAndUpdates[D] = *IUpdate;
603         ++IUpdate;
604       }
605     }
606   }
607   {
608     llvm::DenseSet<const VarDecl *> AlreadyEmittedVars;
609     bool FirstLCV = true;
610     for (const auto *C : D.getClausesOfKind<OMPLastprivateClause>()) {
611       auto IRef = C->varlist_begin();
612       auto ISrcRef = C->source_exprs().begin();
613       auto IDestRef = C->destination_exprs().begin();
614       for (auto *AssignOp : C->assignment_ops()) {
615         auto *PrivateVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
616         QualType Type = PrivateVD->getType();
617         auto *CanonicalVD = PrivateVD->getCanonicalDecl();
618         if (AlreadyEmittedVars.insert(CanonicalVD).second) {
619           // If lastprivate variable is a loop control variable for loop-based
620           // directive, update its value before copyin back to original
621           // variable.
622           if (auto *UpExpr = LoopCountersAndUpdates.lookup(CanonicalVD)) {
623             if (FirstLCV && LastIterVal) {
624               EmitAnyExprToMem(LastIterVal, EmitLValue(IVExpr).getAddress(),
625                                IVExpr->getType().getQualifiers(),
626                                /*IsInitializer=*/false);
627               EmitIgnoredExpr(IncExpr);
628               FirstLCV = false;
629             }
630             EmitIgnoredExpr(UpExpr);
631           }
632           auto *SrcVD = cast<VarDecl>(cast<DeclRefExpr>(*ISrcRef)->getDecl());
633           auto *DestVD = cast<VarDecl>(cast<DeclRefExpr>(*IDestRef)->getDecl());
634           // Get the address of the original variable.
635           Address OriginalAddr = GetAddrOfLocalVar(DestVD);
636           // Get the address of the private variable.
637           Address PrivateAddr = GetAddrOfLocalVar(PrivateVD);
638           if (auto RefTy = PrivateVD->getType()->getAs<ReferenceType>())
639             PrivateAddr =
640               Address(Builder.CreateLoad(PrivateAddr),
641                       getNaturalTypeAlignment(RefTy->getPointeeType()));
642           EmitOMPCopy(Type, OriginalAddr, PrivateAddr, DestVD, SrcVD, AssignOp);
643         }
644         ++IRef;
645         ++ISrcRef;
646         ++IDestRef;
647       }
648     }
649   }
650   if (IsLastIterCond) {
651     EmitBlock(DoneBB, /*IsFinished=*/true);
652   }
653 }
654 
655 void CodeGenFunction::EmitOMPReductionClauseInit(
656     const OMPExecutableDirective &D,
657     CodeGenFunction::OMPPrivateScope &PrivateScope) {
658   if (!HaveInsertPoint())
659     return;
660   for (const auto *C : D.getClausesOfKind<OMPReductionClause>()) {
661     auto ILHS = C->lhs_exprs().begin();
662     auto IRHS = C->rhs_exprs().begin();
663     auto IPriv = C->privates().begin();
664     for (auto IRef : C->varlists()) {
665       auto *LHSVD = cast<VarDecl>(cast<DeclRefExpr>(*ILHS)->getDecl());
666       auto *RHSVD = cast<VarDecl>(cast<DeclRefExpr>(*IRHS)->getDecl());
667       auto *PrivateVD = cast<VarDecl>(cast<DeclRefExpr>(*IPriv)->getDecl());
668       if (auto *OASE = dyn_cast<OMPArraySectionExpr>(IRef)) {
669         auto *Base = OASE->getBase()->IgnoreParenImpCasts();
670         while (auto *TempOASE = dyn_cast<OMPArraySectionExpr>(Base))
671           Base = TempOASE->getBase()->IgnoreParenImpCasts();
672         while (auto *TempASE = dyn_cast<ArraySubscriptExpr>(Base))
673           Base = TempASE->getBase()->IgnoreParenImpCasts();
674         auto *DE = cast<DeclRefExpr>(Base);
675         auto *OrigVD = cast<VarDecl>(DE->getDecl());
676         auto OASELValueLB = EmitOMPArraySectionExpr(OASE);
677         auto OASELValueUB =
678             EmitOMPArraySectionExpr(OASE, /*IsLowerBound=*/false);
679         auto OriginalBaseLValue = EmitLValue(DE);
680         auto BaseLValue = OriginalBaseLValue;
681         auto *Zero = Builder.getInt64(/*C=*/0);
682         llvm::SmallVector<llvm::Value *, 4> Indexes;
683         Indexes.push_back(Zero);
684         auto *ItemTy =
685             OASELValueLB.getPointer()->getType()->getPointerElementType();
686         auto *Ty = BaseLValue.getPointer()->getType()->getPointerElementType();
687         while (Ty != ItemTy) {
688           Indexes.push_back(Zero);
689           Ty = Ty->getPointerElementType();
690         }
691         BaseLValue = MakeAddrLValue(
692             Address(Builder.CreateInBoundsGEP(BaseLValue.getPointer(), Indexes),
693                     OASELValueLB.getAlignment()),
694             OASELValueLB.getType(), OASELValueLB.getAlignmentSource());
695         // Store the address of the original variable associated with the LHS
696         // implicit variable.
697         PrivateScope.addPrivate(LHSVD, [this, OASELValueLB]() -> Address {
698           return OASELValueLB.getAddress();
699         });
700         // Emit reduction copy.
701         bool IsRegistered = PrivateScope.addPrivate(
702             OrigVD, [this, PrivateVD, BaseLValue, OASELValueLB, OASELValueUB,
703                      OriginalBaseLValue]() -> Address {
704               // Emit VarDecl with copy init for arrays.
705               // Get the address of the original variable captured in current
706               // captured region.
707               auto *Size = Builder.CreatePtrDiff(OASELValueUB.getPointer(),
708                                                  OASELValueLB.getPointer());
709               Size = Builder.CreateNUWAdd(
710                   Size, llvm::ConstantInt::get(Size->getType(), /*V=*/1));
711               CodeGenFunction::OpaqueValueMapping OpaqueMap(
712                   *this, cast<OpaqueValueExpr>(
713                              getContext()
714                                  .getAsVariableArrayType(PrivateVD->getType())
715                                  ->getSizeExpr()),
716                   RValue::get(Size));
717               EmitVariablyModifiedType(PrivateVD->getType());
718               auto Emission = EmitAutoVarAlloca(*PrivateVD);
719               auto Addr = Emission.getAllocatedAddress();
720               auto *Init = PrivateVD->getInit();
721               EmitOMPAggregateInit(*this, Addr, PrivateVD->getType(), Init);
722               EmitAutoVarCleanups(Emission);
723               // Emit private VarDecl with reduction init.
724               auto *Offset = Builder.CreatePtrDiff(BaseLValue.getPointer(),
725                                                    OASELValueLB.getPointer());
726               auto *Ptr = Builder.CreateGEP(Addr.getPointer(), Offset);
727               Ptr = Builder.CreatePointerBitCastOrAddrSpaceCast(
728                   Ptr, OriginalBaseLValue.getPointer()->getType());
729               return Address(Ptr, OriginalBaseLValue.getAlignment());
730             });
731         assert(IsRegistered && "private var already registered as private");
732         // Silence the warning about unused variable.
733         (void)IsRegistered;
734         PrivateScope.addPrivate(RHSVD, [this, PrivateVD]() -> Address {
735           return GetAddrOfLocalVar(PrivateVD);
736         });
737       } else if (auto *ASE = dyn_cast<ArraySubscriptExpr>(IRef)) {
738         auto *Base = ASE->getBase()->IgnoreParenImpCasts();
739         while (auto *TempASE = dyn_cast<ArraySubscriptExpr>(Base))
740           Base = TempASE->getBase()->IgnoreParenImpCasts();
741         auto *DE = cast<DeclRefExpr>(Base);
742         auto *OrigVD = cast<VarDecl>(DE->getDecl());
743         auto ASELValue = EmitLValue(ASE);
744         auto OriginalBaseLValue = EmitLValue(DE);
745         auto BaseLValue = OriginalBaseLValue;
746         auto *Zero = Builder.getInt64(/*C=*/0);
747         llvm::SmallVector<llvm::Value *, 4> Indexes;
748         Indexes.push_back(Zero);
749         auto *ItemTy =
750             ASELValue.getPointer()->getType()->getPointerElementType();
751         auto *Ty = BaseLValue.getPointer()->getType()->getPointerElementType();
752         while (Ty != ItemTy) {
753           Indexes.push_back(Zero);
754           Ty = Ty->getPointerElementType();
755         }
756         BaseLValue = MakeAddrLValue(
757             Address(Builder.CreateInBoundsGEP(BaseLValue.getPointer(), Indexes),
758                     ASELValue.getAlignment()),
759             ASELValue.getType(), ASELValue.getAlignmentSource());
760         // Store the address of the original variable associated with the LHS
761         // implicit variable.
762         PrivateScope.addPrivate(LHSVD, [this, ASELValue]() -> Address {
763           return ASELValue.getAddress();
764         });
765         // Emit reduction copy.
766         bool IsRegistered = PrivateScope.addPrivate(
767             OrigVD, [this, PrivateVD, BaseLValue, ASELValue,
768                      OriginalBaseLValue]() -> Address {
769               // Emit private VarDecl with reduction init.
770               EmitDecl(*PrivateVD);
771               auto Addr = GetAddrOfLocalVar(PrivateVD);
772               auto *Offset = Builder.CreatePtrDiff(BaseLValue.getPointer(),
773                                                    ASELValue.getPointer());
774               auto *Ptr = Builder.CreateGEP(Addr.getPointer(), Offset);
775               Ptr = Builder.CreatePointerBitCastOrAddrSpaceCast(
776                   Ptr, OriginalBaseLValue.getPointer()->getType());
777               return Address(Ptr, OriginalBaseLValue.getAlignment());
778             });
779         assert(IsRegistered && "private var already registered as private");
780         // Silence the warning about unused variable.
781         (void)IsRegistered;
782         PrivateScope.addPrivate(RHSVD, [this, PrivateVD]() -> Address {
783           return GetAddrOfLocalVar(PrivateVD);
784         });
785       } else {
786         auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(IRef)->getDecl());
787         // Store the address of the original variable associated with the LHS
788         // implicit variable.
789         PrivateScope.addPrivate(LHSVD, [this, OrigVD, IRef]() -> Address {
790           DeclRefExpr DRE(const_cast<VarDecl *>(OrigVD),
791                           CapturedStmtInfo->lookup(OrigVD) != nullptr,
792                           IRef->getType(), VK_LValue, IRef->getExprLoc());
793           return EmitLValue(&DRE).getAddress();
794         });
795         // Emit reduction copy.
796         bool IsRegistered =
797             PrivateScope.addPrivate(OrigVD, [this, PrivateVD]() -> Address {
798               // Emit private VarDecl with reduction init.
799               EmitDecl(*PrivateVD);
800               return GetAddrOfLocalVar(PrivateVD);
801             });
802         assert(IsRegistered && "private var already registered as private");
803         // Silence the warning about unused variable.
804         (void)IsRegistered;
805         PrivateScope.addPrivate(RHSVD, [this, PrivateVD]() -> Address {
806           return GetAddrOfLocalVar(PrivateVD);
807         });
808       }
809       ++ILHS, ++IRHS, ++IPriv;
810     }
811   }
812 }
813 
814 void CodeGenFunction::EmitOMPReductionClauseFinal(
815     const OMPExecutableDirective &D) {
816   if (!HaveInsertPoint())
817     return;
818   llvm::SmallVector<const Expr *, 8> Privates;
819   llvm::SmallVector<const Expr *, 8> LHSExprs;
820   llvm::SmallVector<const Expr *, 8> RHSExprs;
821   llvm::SmallVector<const Expr *, 8> ReductionOps;
822   bool HasAtLeastOneReduction = false;
823   for (const auto *C : D.getClausesOfKind<OMPReductionClause>()) {
824     HasAtLeastOneReduction = true;
825     Privates.append(C->privates().begin(), C->privates().end());
826     LHSExprs.append(C->lhs_exprs().begin(), C->lhs_exprs().end());
827     RHSExprs.append(C->rhs_exprs().begin(), C->rhs_exprs().end());
828     ReductionOps.append(C->reduction_ops().begin(), C->reduction_ops().end());
829   }
830   if (HasAtLeastOneReduction) {
831     // Emit nowait reduction if nowait clause is present or directive is a
832     // parallel directive (it always has implicit barrier).
833     CGM.getOpenMPRuntime().emitReduction(
834         *this, D.getLocEnd(), Privates, LHSExprs, RHSExprs, ReductionOps,
835         D.getSingleClause<OMPNowaitClause>() ||
836             isOpenMPParallelDirective(D.getDirectiveKind()) ||
837             D.getDirectiveKind() == OMPD_simd,
838         D.getDirectiveKind() == OMPD_simd);
839   }
840 }
841 
842 static void emitCommonOMPParallelDirective(CodeGenFunction &CGF,
843                                            const OMPExecutableDirective &S,
844                                            OpenMPDirectiveKind InnermostKind,
845                                            const RegionCodeGenTy &CodeGen) {
846   auto CS = cast<CapturedStmt>(S.getAssociatedStmt());
847   llvm::SmallVector<llvm::Value *, 16> CapturedVars;
848   CGF.GenerateOpenMPCapturedVars(*CS, CapturedVars);
849   auto OutlinedFn = CGF.CGM.getOpenMPRuntime().emitParallelOutlinedFunction(
850       S, *CS->getCapturedDecl()->param_begin(), InnermostKind, CodeGen);
851   if (const auto *NumThreadsClause = S.getSingleClause<OMPNumThreadsClause>()) {
852     CodeGenFunction::RunCleanupsScope NumThreadsScope(CGF);
853     auto NumThreads = CGF.EmitScalarExpr(NumThreadsClause->getNumThreads(),
854                                          /*IgnoreResultAssign*/ true);
855     CGF.CGM.getOpenMPRuntime().emitNumThreadsClause(
856         CGF, NumThreads, NumThreadsClause->getLocStart());
857   }
858   if (const auto *ProcBindClause = S.getSingleClause<OMPProcBindClause>()) {
859     CodeGenFunction::RunCleanupsScope NumThreadsScope(CGF);
860     CGF.CGM.getOpenMPRuntime().emitProcBindClause(
861         CGF, ProcBindClause->getProcBindKind(), ProcBindClause->getLocStart());
862   }
863   const Expr *IfCond = nullptr;
864   for (const auto *C : S.getClausesOfKind<OMPIfClause>()) {
865     if (C->getNameModifier() == OMPD_unknown ||
866         C->getNameModifier() == OMPD_parallel) {
867       IfCond = C->getCondition();
868       break;
869     }
870   }
871   CGF.CGM.getOpenMPRuntime().emitParallelCall(CGF, S.getLocStart(), OutlinedFn,
872                                               CapturedVars, IfCond);
873 }
874 
875 void CodeGenFunction::EmitOMPParallelDirective(const OMPParallelDirective &S) {
876   LexicalScope Scope(*this, S.getSourceRange());
877   // Emit parallel region as a standalone region.
878   auto &&CodeGen = [&S](CodeGenFunction &CGF) {
879     OMPPrivateScope PrivateScope(CGF);
880     bool Copyins = CGF.EmitOMPCopyinClause(S);
881     bool Firstprivates = CGF.EmitOMPFirstprivateClause(S, PrivateScope);
882     if (Copyins || Firstprivates) {
883       // Emit implicit barrier to synchronize threads and avoid data races on
884       // initialization of firstprivate variables or propagation master's thread
885       // values of threadprivate variables to local instances of that variables
886       // of all other implicit threads.
887       CGF.CGM.getOpenMPRuntime().emitBarrierCall(
888           CGF, S.getLocStart(), OMPD_unknown, /*EmitChecks=*/false,
889           /*ForceSimpleCall=*/true);
890     }
891     CGF.EmitOMPPrivateClause(S, PrivateScope);
892     CGF.EmitOMPReductionClauseInit(S, PrivateScope);
893     (void)PrivateScope.Privatize();
894     CGF.EmitStmt(cast<CapturedStmt>(S.getAssociatedStmt())->getCapturedStmt());
895     CGF.EmitOMPReductionClauseFinal(S);
896   };
897   emitCommonOMPParallelDirective(*this, S, OMPD_parallel, CodeGen);
898 }
899 
900 void CodeGenFunction::EmitOMPLoopBody(const OMPLoopDirective &D,
901                                       JumpDest LoopExit) {
902   RunCleanupsScope BodyScope(*this);
903   // Update counters values on current iteration.
904   for (auto I : D.updates()) {
905     EmitIgnoredExpr(I);
906   }
907   // Update the linear variables.
908   for (const auto *C : D.getClausesOfKind<OMPLinearClause>()) {
909     for (auto U : C->updates()) {
910       EmitIgnoredExpr(U);
911     }
912   }
913 
914   // On a continue in the body, jump to the end.
915   auto Continue = getJumpDestInCurrentScope("omp.body.continue");
916   BreakContinueStack.push_back(BreakContinue(LoopExit, Continue));
917   // Emit loop body.
918   EmitStmt(D.getBody());
919   // The end (updates/cleanups).
920   EmitBlock(Continue.getBlock());
921   BreakContinueStack.pop_back();
922     // TODO: Update lastprivates if the SeparateIter flag is true.
923     // This will be implemented in a follow-up OMPLastprivateClause patch, but
924     // result should be still correct without it, as we do not make these
925     // variables private yet.
926 }
927 
928 void CodeGenFunction::EmitOMPInnerLoop(
929     const Stmt &S, bool RequiresCleanup, const Expr *LoopCond,
930     const Expr *IncExpr,
931     const llvm::function_ref<void(CodeGenFunction &)> &BodyGen,
932     const llvm::function_ref<void(CodeGenFunction &)> &PostIncGen) {
933   auto LoopExit = getJumpDestInCurrentScope("omp.inner.for.end");
934 
935   // Start the loop with a block that tests the condition.
936   auto CondBlock = createBasicBlock("omp.inner.for.cond");
937   EmitBlock(CondBlock);
938   LoopStack.push(CondBlock);
939 
940   // If there are any cleanups between here and the loop-exit scope,
941   // create a block to stage a loop exit along.
942   auto ExitBlock = LoopExit.getBlock();
943   if (RequiresCleanup)
944     ExitBlock = createBasicBlock("omp.inner.for.cond.cleanup");
945 
946   auto LoopBody = createBasicBlock("omp.inner.for.body");
947 
948   // Emit condition.
949   EmitBranchOnBoolExpr(LoopCond, LoopBody, ExitBlock, getProfileCount(&S));
950   if (ExitBlock != LoopExit.getBlock()) {
951     EmitBlock(ExitBlock);
952     EmitBranchThroughCleanup(LoopExit);
953   }
954 
955   EmitBlock(LoopBody);
956   incrementProfileCounter(&S);
957 
958   // Create a block for the increment.
959   auto Continue = getJumpDestInCurrentScope("omp.inner.for.inc");
960   BreakContinueStack.push_back(BreakContinue(LoopExit, Continue));
961 
962   BodyGen(*this);
963 
964   // Emit "IV = IV + 1" and a back-edge to the condition block.
965   EmitBlock(Continue.getBlock());
966   EmitIgnoredExpr(IncExpr);
967   PostIncGen(*this);
968   BreakContinueStack.pop_back();
969   EmitBranch(CondBlock);
970   LoopStack.pop();
971   // Emit the fall-through block.
972   EmitBlock(LoopExit.getBlock());
973 }
974 
975 void CodeGenFunction::EmitOMPLinearClauseInit(const OMPLoopDirective &D) {
976   if (!HaveInsertPoint())
977     return;
978   // Emit inits for the linear variables.
979   for (const auto *C : D.getClausesOfKind<OMPLinearClause>()) {
980     for (auto Init : C->inits()) {
981       auto *VD = cast<VarDecl>(cast<DeclRefExpr>(Init)->getDecl());
982       auto *OrigVD = cast<VarDecl>(
983           cast<DeclRefExpr>(VD->getInit()->IgnoreImpCasts())->getDecl());
984       DeclRefExpr DRE(const_cast<VarDecl *>(OrigVD),
985                       CapturedStmtInfo->lookup(OrigVD) != nullptr,
986                       VD->getInit()->getType(), VK_LValue,
987                       VD->getInit()->getExprLoc());
988       AutoVarEmission Emission = EmitAutoVarAlloca(*VD);
989       EmitExprAsInit(&DRE, VD,
990                MakeAddrLValue(Emission.getAllocatedAddress(), VD->getType()),
991                      /*capturedByInit=*/false);
992       EmitAutoVarCleanups(Emission);
993     }
994     // Emit the linear steps for the linear clauses.
995     // If a step is not constant, it is pre-calculated before the loop.
996     if (auto CS = cast_or_null<BinaryOperator>(C->getCalcStep()))
997       if (auto SaveRef = cast<DeclRefExpr>(CS->getLHS())) {
998         EmitVarDecl(*cast<VarDecl>(SaveRef->getDecl()));
999         // Emit calculation of the linear step.
1000         EmitIgnoredExpr(CS);
1001       }
1002   }
1003 }
1004 
1005 static void emitLinearClauseFinal(CodeGenFunction &CGF,
1006                                   const OMPLoopDirective &D) {
1007   if (!CGF.HaveInsertPoint())
1008     return;
1009   // Emit the final values of the linear variables.
1010   for (const auto *C : D.getClausesOfKind<OMPLinearClause>()) {
1011     auto IC = C->varlist_begin();
1012     for (auto F : C->finals()) {
1013       auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IC)->getDecl());
1014       DeclRefExpr DRE(const_cast<VarDecl *>(OrigVD),
1015                       CGF.CapturedStmtInfo->lookup(OrigVD) != nullptr,
1016                       (*IC)->getType(), VK_LValue, (*IC)->getExprLoc());
1017       Address OrigAddr = CGF.EmitLValue(&DRE).getAddress();
1018       CodeGenFunction::OMPPrivateScope VarScope(CGF);
1019       VarScope.addPrivate(OrigVD,
1020                           [OrigAddr]() -> Address { return OrigAddr; });
1021       (void)VarScope.Privatize();
1022       CGF.EmitIgnoredExpr(F);
1023       ++IC;
1024     }
1025   }
1026 }
1027 
1028 static void emitAlignedClause(CodeGenFunction &CGF,
1029                               const OMPExecutableDirective &D) {
1030   if (!CGF.HaveInsertPoint())
1031     return;
1032   for (const auto *Clause : D.getClausesOfKind<OMPAlignedClause>()) {
1033     unsigned ClauseAlignment = 0;
1034     if (auto AlignmentExpr = Clause->getAlignment()) {
1035       auto AlignmentCI =
1036           cast<llvm::ConstantInt>(CGF.EmitScalarExpr(AlignmentExpr));
1037       ClauseAlignment = static_cast<unsigned>(AlignmentCI->getZExtValue());
1038     }
1039     for (auto E : Clause->varlists()) {
1040       unsigned Alignment = ClauseAlignment;
1041       if (Alignment == 0) {
1042         // OpenMP [2.8.1, Description]
1043         // If no optional parameter is specified, implementation-defined default
1044         // alignments for SIMD instructions on the target platforms are assumed.
1045         Alignment =
1046             CGF.getContext()
1047                 .toCharUnitsFromBits(CGF.getContext().getOpenMPDefaultSimdAlign(
1048                     E->getType()->getPointeeType()))
1049                 .getQuantity();
1050       }
1051       assert((Alignment == 0 || llvm::isPowerOf2_32(Alignment)) &&
1052              "alignment is not power of 2");
1053       if (Alignment != 0) {
1054         llvm::Value *PtrValue = CGF.EmitScalarExpr(E);
1055         CGF.EmitAlignmentAssumption(PtrValue, Alignment);
1056       }
1057     }
1058   }
1059 }
1060 
1061 static void emitPrivateLoopCounters(CodeGenFunction &CGF,
1062                                     CodeGenFunction::OMPPrivateScope &LoopScope,
1063                                     ArrayRef<Expr *> Counters,
1064                                     ArrayRef<Expr *> PrivateCounters) {
1065   if (!CGF.HaveInsertPoint())
1066     return;
1067   auto I = PrivateCounters.begin();
1068   for (auto *E : Counters) {
1069     auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
1070     auto *PrivateVD = cast<VarDecl>(cast<DeclRefExpr>(*I)->getDecl());
1071     Address Addr = Address::invalid();
1072     (void)LoopScope.addPrivate(PrivateVD, [&]() -> Address {
1073       // Emit var without initialization.
1074       auto VarEmission = CGF.EmitAutoVarAlloca(*PrivateVD);
1075       CGF.EmitAutoVarCleanups(VarEmission);
1076       Addr = VarEmission.getAllocatedAddress();
1077       return Addr;
1078     });
1079     (void)LoopScope.addPrivate(VD, [&]() -> Address { return Addr; });
1080     ++I;
1081   }
1082 }
1083 
1084 static void emitPreCond(CodeGenFunction &CGF, const OMPLoopDirective &S,
1085                         const Expr *Cond, llvm::BasicBlock *TrueBlock,
1086                         llvm::BasicBlock *FalseBlock, uint64_t TrueCount) {
1087   if (!CGF.HaveInsertPoint())
1088     return;
1089   {
1090     CodeGenFunction::OMPPrivateScope PreCondScope(CGF);
1091     emitPrivateLoopCounters(CGF, PreCondScope, S.counters(),
1092                             S.private_counters());
1093     (void)PreCondScope.Privatize();
1094     // Get initial values of real counters.
1095     for (auto I : S.inits()) {
1096       CGF.EmitIgnoredExpr(I);
1097     }
1098   }
1099   // Check that loop is executed at least one time.
1100   CGF.EmitBranchOnBoolExpr(Cond, TrueBlock, FalseBlock, TrueCount);
1101 }
1102 
1103 static void
1104 emitPrivateLinearVars(CodeGenFunction &CGF, const OMPExecutableDirective &D,
1105                       CodeGenFunction::OMPPrivateScope &PrivateScope) {
1106   if (!CGF.HaveInsertPoint())
1107     return;
1108   for (const auto *C : D.getClausesOfKind<OMPLinearClause>()) {
1109     auto CurPrivate = C->privates().begin();
1110     for (auto *E : C->varlists()) {
1111       auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
1112       auto *PrivateVD =
1113           cast<VarDecl>(cast<DeclRefExpr>(*CurPrivate)->getDecl());
1114       bool IsRegistered = PrivateScope.addPrivate(VD, [&]() -> Address {
1115         // Emit private VarDecl with copy init.
1116         CGF.EmitVarDecl(*PrivateVD);
1117         return CGF.GetAddrOfLocalVar(PrivateVD);
1118       });
1119       assert(IsRegistered && "linear var already registered as private");
1120       // Silence the warning about unused variable.
1121       (void)IsRegistered;
1122       ++CurPrivate;
1123     }
1124   }
1125 }
1126 
1127 static void emitSimdlenSafelenClause(CodeGenFunction &CGF,
1128                                      const OMPExecutableDirective &D,
1129                                      bool IsMonotonic) {
1130   if (!CGF.HaveInsertPoint())
1131     return;
1132   if (const auto *C = D.getSingleClause<OMPSimdlenClause>()) {
1133     RValue Len = CGF.EmitAnyExpr(C->getSimdlen(), AggValueSlot::ignored(),
1134                                  /*ignoreResult=*/true);
1135     llvm::ConstantInt *Val = cast<llvm::ConstantInt>(Len.getScalarVal());
1136     CGF.LoopStack.setVectorizeWidth(Val->getZExtValue());
1137     // In presence of finite 'safelen', it may be unsafe to mark all
1138     // the memory instructions parallel, because loop-carried
1139     // dependences of 'safelen' iterations are possible.
1140     if (!IsMonotonic)
1141       CGF.LoopStack.setParallel(!D.getSingleClause<OMPSafelenClause>());
1142   } else if (const auto *C = D.getSingleClause<OMPSafelenClause>()) {
1143     RValue Len = CGF.EmitAnyExpr(C->getSafelen(), AggValueSlot::ignored(),
1144                                  /*ignoreResult=*/true);
1145     llvm::ConstantInt *Val = cast<llvm::ConstantInt>(Len.getScalarVal());
1146     CGF.LoopStack.setVectorizeWidth(Val->getZExtValue());
1147     // In presence of finite 'safelen', it may be unsafe to mark all
1148     // the memory instructions parallel, because loop-carried
1149     // dependences of 'safelen' iterations are possible.
1150     CGF.LoopStack.setParallel(false);
1151   }
1152 }
1153 
1154 void CodeGenFunction::EmitOMPSimdInit(const OMPLoopDirective &D,
1155                                       bool IsMonotonic) {
1156   // Walk clauses and process safelen/lastprivate.
1157   LoopStack.setParallel(!IsMonotonic);
1158   LoopStack.setVectorizeEnable(true);
1159   emitSimdlenSafelenClause(*this, D, IsMonotonic);
1160 }
1161 
1162 void CodeGenFunction::EmitOMPSimdFinal(const OMPLoopDirective &D) {
1163   if (!HaveInsertPoint())
1164     return;
1165   auto IC = D.counters().begin();
1166   for (auto F : D.finals()) {
1167     auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>((*IC))->getDecl());
1168     if (LocalDeclMap.count(OrigVD) || CapturedStmtInfo->lookup(OrigVD)) {
1169       DeclRefExpr DRE(const_cast<VarDecl *>(OrigVD),
1170                       CapturedStmtInfo->lookup(OrigVD) != nullptr,
1171                       (*IC)->getType(), VK_LValue, (*IC)->getExprLoc());
1172       Address OrigAddr = EmitLValue(&DRE).getAddress();
1173       OMPPrivateScope VarScope(*this);
1174       VarScope.addPrivate(OrigVD,
1175                           [OrigAddr]() -> Address { return OrigAddr; });
1176       (void)VarScope.Privatize();
1177       EmitIgnoredExpr(F);
1178     }
1179     ++IC;
1180   }
1181   emitLinearClauseFinal(*this, D);
1182 }
1183 
1184 void CodeGenFunction::EmitOMPSimdDirective(const OMPSimdDirective &S) {
1185   auto &&CodeGen = [&S](CodeGenFunction &CGF) {
1186     // if (PreCond) {
1187     //   for (IV in 0..LastIteration) BODY;
1188     //   <Final counter/linear vars updates>;
1189     // }
1190     //
1191 
1192     // Emit: if (PreCond) - begin.
1193     // If the condition constant folds and can be elided, avoid emitting the
1194     // whole loop.
1195     bool CondConstant;
1196     llvm::BasicBlock *ContBlock = nullptr;
1197     if (CGF.ConstantFoldsToSimpleInteger(S.getPreCond(), CondConstant)) {
1198       if (!CondConstant)
1199         return;
1200     } else {
1201       auto *ThenBlock = CGF.createBasicBlock("simd.if.then");
1202       ContBlock = CGF.createBasicBlock("simd.if.end");
1203       emitPreCond(CGF, S, S.getPreCond(), ThenBlock, ContBlock,
1204                   CGF.getProfileCount(&S));
1205       CGF.EmitBlock(ThenBlock);
1206       CGF.incrementProfileCounter(&S);
1207     }
1208 
1209     // Emit the loop iteration variable.
1210     const Expr *IVExpr = S.getIterationVariable();
1211     const VarDecl *IVDecl = cast<VarDecl>(cast<DeclRefExpr>(IVExpr)->getDecl());
1212     CGF.EmitVarDecl(*IVDecl);
1213     CGF.EmitIgnoredExpr(S.getInit());
1214 
1215     // Emit the iterations count variable.
1216     // If it is not a variable, Sema decided to calculate iterations count on
1217     // each iteration (e.g., it is foldable into a constant).
1218     if (auto LIExpr = dyn_cast<DeclRefExpr>(S.getLastIteration())) {
1219       CGF.EmitVarDecl(*cast<VarDecl>(LIExpr->getDecl()));
1220       // Emit calculation of the iterations count.
1221       CGF.EmitIgnoredExpr(S.getCalcLastIteration());
1222     }
1223 
1224     CGF.EmitOMPSimdInit(S);
1225 
1226     emitAlignedClause(CGF, S);
1227     CGF.EmitOMPLinearClauseInit(S);
1228     bool HasLastprivateClause;
1229     {
1230       OMPPrivateScope LoopScope(CGF);
1231       emitPrivateLoopCounters(CGF, LoopScope, S.counters(),
1232                               S.private_counters());
1233       emitPrivateLinearVars(CGF, S, LoopScope);
1234       CGF.EmitOMPPrivateClause(S, LoopScope);
1235       CGF.EmitOMPReductionClauseInit(S, LoopScope);
1236       HasLastprivateClause = CGF.EmitOMPLastprivateClauseInit(S, LoopScope);
1237       (void)LoopScope.Privatize();
1238       CGF.EmitOMPInnerLoop(S, LoopScope.requiresCleanups(), S.getCond(),
1239                            S.getInc(),
1240                            [&S](CodeGenFunction &CGF) {
1241                              CGF.EmitOMPLoopBody(S, JumpDest());
1242                              CGF.EmitStopPoint(&S);
1243                            },
1244                            [](CodeGenFunction &) {});
1245       // Emit final copy of the lastprivate variables at the end of loops.
1246       if (HasLastprivateClause) {
1247         CGF.EmitOMPLastprivateClauseFinal(S);
1248       }
1249       CGF.EmitOMPReductionClauseFinal(S);
1250     }
1251     CGF.EmitOMPSimdFinal(S);
1252     // Emit: if (PreCond) - end.
1253     if (ContBlock) {
1254       CGF.EmitBranch(ContBlock);
1255       CGF.EmitBlock(ContBlock, true);
1256     }
1257   };
1258   CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_simd, CodeGen);
1259 }
1260 
1261 void CodeGenFunction::EmitOMPForOuterLoop(
1262     OpenMPScheduleClauseKind ScheduleKind, bool IsMonotonic,
1263     const OMPLoopDirective &S, OMPPrivateScope &LoopScope, bool Ordered,
1264     Address LB, Address UB, Address ST, Address IL, llvm::Value *Chunk) {
1265   auto &RT = CGM.getOpenMPRuntime();
1266 
1267   // Dynamic scheduling of the outer loop (dynamic, guided, auto, runtime).
1268   const bool DynamicOrOrdered = Ordered || RT.isDynamic(ScheduleKind);
1269 
1270   assert((Ordered ||
1271           !RT.isStaticNonchunked(ScheduleKind, /*Chunked=*/Chunk != nullptr)) &&
1272          "static non-chunked schedule does not need outer loop");
1273 
1274   // Emit outer loop.
1275   //
1276   // OpenMP [2.7.1, Loop Construct, Description, table 2-1]
1277   // When schedule(dynamic,chunk_size) is specified, the iterations are
1278   // distributed to threads in the team in chunks as the threads request them.
1279   // Each thread executes a chunk of iterations, then requests another chunk,
1280   // until no chunks remain to be distributed. Each chunk contains chunk_size
1281   // iterations, except for the last chunk to be distributed, which may have
1282   // fewer iterations. When no chunk_size is specified, it defaults to 1.
1283   //
1284   // When schedule(guided,chunk_size) is specified, the iterations are assigned
1285   // to threads in the team in chunks as the executing threads request them.
1286   // Each thread executes a chunk of iterations, then requests another chunk,
1287   // until no chunks remain to be assigned. For a chunk_size of 1, the size of
1288   // each chunk is proportional to the number of unassigned iterations divided
1289   // by the number of threads in the team, decreasing to 1. For a chunk_size
1290   // with value k (greater than 1), the size of each chunk is determined in the
1291   // same way, with the restriction that the chunks do not contain fewer than k
1292   // iterations (except for the last chunk to be assigned, which may have fewer
1293   // than k iterations).
1294   //
1295   // When schedule(auto) is specified, the decision regarding scheduling is
1296   // delegated to the compiler and/or runtime system. The programmer gives the
1297   // implementation the freedom to choose any possible mapping of iterations to
1298   // threads in the team.
1299   //
1300   // When schedule(runtime) is specified, the decision regarding scheduling is
1301   // deferred until run time, and the schedule and chunk size are taken from the
1302   // run-sched-var ICV. If the ICV is set to auto, the schedule is
1303   // implementation defined
1304   //
1305   // while(__kmpc_dispatch_next(&LB, &UB)) {
1306   //   idx = LB;
1307   //   while (idx <= UB) { BODY; ++idx;
1308   //   __kmpc_dispatch_fini_(4|8)[u](); // For ordered loops only.
1309   //   } // inner loop
1310   // }
1311   //
1312   // OpenMP [2.7.1, Loop Construct, Description, table 2-1]
1313   // When schedule(static, chunk_size) is specified, iterations are divided into
1314   // chunks of size chunk_size, and the chunks are assigned to the threads in
1315   // the team in a round-robin fashion in the order of the thread number.
1316   //
1317   // while(UB = min(UB, GlobalUB), idx = LB, idx < UB) {
1318   //   while (idx <= UB) { BODY; ++idx; } // inner loop
1319   //   LB = LB + ST;
1320   //   UB = UB + ST;
1321   // }
1322   //
1323 
1324   const Expr *IVExpr = S.getIterationVariable();
1325   const unsigned IVSize = getContext().getTypeSize(IVExpr->getType());
1326   const bool IVSigned = IVExpr->getType()->hasSignedIntegerRepresentation();
1327 
1328   if (DynamicOrOrdered) {
1329     llvm::Value *UBVal = EmitScalarExpr(S.getLastIteration());
1330     RT.emitForDispatchInit(*this, S.getLocStart(), ScheduleKind,
1331                            IVSize, IVSigned, Ordered, UBVal, Chunk);
1332   } else {
1333     RT.emitForStaticInit(*this, S.getLocStart(), ScheduleKind,
1334                          IVSize, IVSigned, Ordered, IL, LB, UB, ST, Chunk);
1335   }
1336 
1337   auto LoopExit = getJumpDestInCurrentScope("omp.dispatch.end");
1338 
1339   // Start the loop with a block that tests the condition.
1340   auto CondBlock = createBasicBlock("omp.dispatch.cond");
1341   EmitBlock(CondBlock);
1342   LoopStack.push(CondBlock);
1343 
1344   llvm::Value *BoolCondVal = nullptr;
1345   if (!DynamicOrOrdered) {
1346     // UB = min(UB, GlobalUB)
1347     EmitIgnoredExpr(S.getEnsureUpperBound());
1348     // IV = LB
1349     EmitIgnoredExpr(S.getInit());
1350     // IV < UB
1351     BoolCondVal = EvaluateExprAsBool(S.getCond());
1352   } else {
1353     BoolCondVal = RT.emitForNext(*this, S.getLocStart(), IVSize, IVSigned,
1354                                     IL, LB, UB, ST);
1355   }
1356 
1357   // If there are any cleanups between here and the loop-exit scope,
1358   // create a block to stage a loop exit along.
1359   auto ExitBlock = LoopExit.getBlock();
1360   if (LoopScope.requiresCleanups())
1361     ExitBlock = createBasicBlock("omp.dispatch.cleanup");
1362 
1363   auto LoopBody = createBasicBlock("omp.dispatch.body");
1364   Builder.CreateCondBr(BoolCondVal, LoopBody, ExitBlock);
1365   if (ExitBlock != LoopExit.getBlock()) {
1366     EmitBlock(ExitBlock);
1367     EmitBranchThroughCleanup(LoopExit);
1368   }
1369   EmitBlock(LoopBody);
1370 
1371   // Emit "IV = LB" (in case of static schedule, we have already calculated new
1372   // LB for loop condition and emitted it above).
1373   if (DynamicOrOrdered)
1374     EmitIgnoredExpr(S.getInit());
1375 
1376   // Create a block for the increment.
1377   auto Continue = getJumpDestInCurrentScope("omp.dispatch.inc");
1378   BreakContinueStack.push_back(BreakContinue(LoopExit, Continue));
1379 
1380   // Generate !llvm.loop.parallel metadata for loads and stores for loops
1381   // with dynamic/guided scheduling and without ordered clause.
1382   if (!isOpenMPSimdDirective(S.getDirectiveKind()))
1383     LoopStack.setParallel(!IsMonotonic);
1384   else
1385     EmitOMPSimdInit(S, IsMonotonic);
1386 
1387   SourceLocation Loc = S.getLocStart();
1388   EmitOMPInnerLoop(S, LoopScope.requiresCleanups(), S.getCond(), S.getInc(),
1389                    [&S, LoopExit](CodeGenFunction &CGF) {
1390                      CGF.EmitOMPLoopBody(S, LoopExit);
1391                      CGF.EmitStopPoint(&S);
1392                    },
1393                    [Ordered, IVSize, IVSigned, Loc](CodeGenFunction &CGF) {
1394                      if (Ordered) {
1395                        CGF.CGM.getOpenMPRuntime().emitForOrderedIterationEnd(
1396                            CGF, Loc, IVSize, IVSigned);
1397                      }
1398                    });
1399 
1400   EmitBlock(Continue.getBlock());
1401   BreakContinueStack.pop_back();
1402   if (!DynamicOrOrdered) {
1403     // Emit "LB = LB + Stride", "UB = UB + Stride".
1404     EmitIgnoredExpr(S.getNextLowerBound());
1405     EmitIgnoredExpr(S.getNextUpperBound());
1406   }
1407 
1408   EmitBranch(CondBlock);
1409   LoopStack.pop();
1410   // Emit the fall-through block.
1411   EmitBlock(LoopExit.getBlock());
1412 
1413   // Tell the runtime we are done.
1414   if (!DynamicOrOrdered)
1415     RT.emitForStaticFinish(*this, S.getLocEnd());
1416 }
1417 
1418 /// \brief Emit a helper variable and return corresponding lvalue.
1419 static LValue EmitOMPHelperVar(CodeGenFunction &CGF,
1420                                const DeclRefExpr *Helper) {
1421   auto VDecl = cast<VarDecl>(Helper->getDecl());
1422   CGF.EmitVarDecl(*VDecl);
1423   return CGF.EmitLValue(Helper);
1424 }
1425 
1426 namespace {
1427   struct ScheduleKindModifiersTy {
1428     OpenMPScheduleClauseKind Kind;
1429     OpenMPScheduleClauseModifier M1;
1430     OpenMPScheduleClauseModifier M2;
1431     ScheduleKindModifiersTy(OpenMPScheduleClauseKind Kind,
1432                             OpenMPScheduleClauseModifier M1,
1433                             OpenMPScheduleClauseModifier M2)
1434         : Kind(Kind), M1(M1), M2(M2) {}
1435   };
1436 } // namespace
1437 
1438 static std::pair<llvm::Value * /*Chunk*/, ScheduleKindModifiersTy>
1439 emitScheduleClause(CodeGenFunction &CGF, const OMPLoopDirective &S,
1440                    bool OuterRegion) {
1441   // Detect the loop schedule kind and chunk.
1442   auto ScheduleKind = OMPC_SCHEDULE_unknown;
1443   OpenMPScheduleClauseModifier M1 = OMPC_SCHEDULE_MODIFIER_unknown;
1444   OpenMPScheduleClauseModifier M2 = OMPC_SCHEDULE_MODIFIER_unknown;
1445   llvm::Value *Chunk = nullptr;
1446   if (const auto *C = S.getSingleClause<OMPScheduleClause>()) {
1447     ScheduleKind = C->getScheduleKind();
1448     M1 = C->getFirstScheduleModifier();
1449     M2 = C->getSecondScheduleModifier();
1450     if (const auto *Ch = C->getChunkSize()) {
1451       if (auto *ImpRef = cast_or_null<DeclRefExpr>(C->getHelperChunkSize())) {
1452         if (OuterRegion) {
1453           const VarDecl *ImpVar = cast<VarDecl>(ImpRef->getDecl());
1454           CGF.EmitVarDecl(*ImpVar);
1455           CGF.EmitStoreThroughLValue(
1456               CGF.EmitAnyExpr(Ch),
1457               CGF.MakeAddrLValue(CGF.GetAddrOfLocalVar(ImpVar),
1458                                  ImpVar->getType()));
1459         } else {
1460           Ch = ImpRef;
1461         }
1462       }
1463       if (!C->getHelperChunkSize() || !OuterRegion) {
1464         Chunk = CGF.EmitScalarExpr(Ch);
1465         Chunk = CGF.EmitScalarConversion(Chunk, Ch->getType(),
1466                                          S.getIterationVariable()->getType(),
1467                                          S.getLocStart());
1468       }
1469     }
1470   }
1471   return std::make_pair(Chunk, ScheduleKindModifiersTy(ScheduleKind, M1, M2));
1472 }
1473 
1474 bool CodeGenFunction::EmitOMPWorksharingLoop(const OMPLoopDirective &S) {
1475   // Emit the loop iteration variable.
1476   auto IVExpr = cast<DeclRefExpr>(S.getIterationVariable());
1477   auto IVDecl = cast<VarDecl>(IVExpr->getDecl());
1478   EmitVarDecl(*IVDecl);
1479 
1480   // Emit the iterations count variable.
1481   // If it is not a variable, Sema decided to calculate iterations count on each
1482   // iteration (e.g., it is foldable into a constant).
1483   if (auto LIExpr = dyn_cast<DeclRefExpr>(S.getLastIteration())) {
1484     EmitVarDecl(*cast<VarDecl>(LIExpr->getDecl()));
1485     // Emit calculation of the iterations count.
1486     EmitIgnoredExpr(S.getCalcLastIteration());
1487   }
1488 
1489   auto &RT = CGM.getOpenMPRuntime();
1490 
1491   bool HasLastprivateClause;
1492   // Check pre-condition.
1493   {
1494     // Skip the entire loop if we don't meet the precondition.
1495     // If the condition constant folds and can be elided, avoid emitting the
1496     // whole loop.
1497     bool CondConstant;
1498     llvm::BasicBlock *ContBlock = nullptr;
1499     if (ConstantFoldsToSimpleInteger(S.getPreCond(), CondConstant)) {
1500       if (!CondConstant)
1501         return false;
1502     } else {
1503       auto *ThenBlock = createBasicBlock("omp.precond.then");
1504       ContBlock = createBasicBlock("omp.precond.end");
1505       emitPreCond(*this, S, S.getPreCond(), ThenBlock, ContBlock,
1506                   getProfileCount(&S));
1507       EmitBlock(ThenBlock);
1508       incrementProfileCounter(&S);
1509     }
1510 
1511     emitAlignedClause(*this, S);
1512     EmitOMPLinearClauseInit(S);
1513     // Emit 'then' code.
1514     {
1515       // Emit helper vars inits.
1516       LValue LB =
1517           EmitOMPHelperVar(*this, cast<DeclRefExpr>(S.getLowerBoundVariable()));
1518       LValue UB =
1519           EmitOMPHelperVar(*this, cast<DeclRefExpr>(S.getUpperBoundVariable()));
1520       LValue ST =
1521           EmitOMPHelperVar(*this, cast<DeclRefExpr>(S.getStrideVariable()));
1522       LValue IL =
1523           EmitOMPHelperVar(*this, cast<DeclRefExpr>(S.getIsLastIterVariable()));
1524 
1525       OMPPrivateScope LoopScope(*this);
1526       if (EmitOMPFirstprivateClause(S, LoopScope)) {
1527         // Emit implicit barrier to synchronize threads and avoid data races on
1528         // initialization of firstprivate variables.
1529         CGM.getOpenMPRuntime().emitBarrierCall(
1530             *this, S.getLocStart(), OMPD_unknown, /*EmitChecks=*/false,
1531             /*ForceSimpleCall=*/true);
1532       }
1533       EmitOMPPrivateClause(S, LoopScope);
1534       HasLastprivateClause = EmitOMPLastprivateClauseInit(S, LoopScope);
1535       EmitOMPReductionClauseInit(S, LoopScope);
1536       emitPrivateLoopCounters(*this, LoopScope, S.counters(),
1537                               S.private_counters());
1538       emitPrivateLinearVars(*this, S, LoopScope);
1539       (void)LoopScope.Privatize();
1540 
1541       // Detect the loop schedule kind and chunk.
1542       llvm::Value *Chunk;
1543       OpenMPScheduleClauseKind ScheduleKind;
1544       auto ScheduleInfo =
1545           emitScheduleClause(*this, S, /*OuterRegion=*/false);
1546       Chunk = ScheduleInfo.first;
1547       ScheduleKind = ScheduleInfo.second.Kind;
1548       const OpenMPScheduleClauseModifier M1 = ScheduleInfo.second.M1;
1549       const OpenMPScheduleClauseModifier M2 = ScheduleInfo.second.M2;
1550       const unsigned IVSize = getContext().getTypeSize(IVExpr->getType());
1551       const bool IVSigned = IVExpr->getType()->hasSignedIntegerRepresentation();
1552       const bool Ordered = S.getSingleClause<OMPOrderedClause>() != nullptr;
1553       // OpenMP 4.5, 2.7.1 Loop Construct, Description.
1554       // If the static schedule kind is specified or if the ordered clause is
1555       // specified, and if no monotonic modifier is specified, the effect will
1556       // be as if the monotonic modifier was specified.
1557       if (RT.isStaticNonchunked(ScheduleKind,
1558                                 /* Chunked */ Chunk != nullptr) &&
1559           !Ordered) {
1560         if (isOpenMPSimdDirective(S.getDirectiveKind()))
1561           EmitOMPSimdInit(S, /*IsMonotonic=*/true);
1562         // OpenMP [2.7.1, Loop Construct, Description, table 2-1]
1563         // When no chunk_size is specified, the iteration space is divided into
1564         // chunks that are approximately equal in size, and at most one chunk is
1565         // distributed to each thread. Note that the size of the chunks is
1566         // unspecified in this case.
1567         RT.emitForStaticInit(*this, S.getLocStart(), ScheduleKind,
1568                              IVSize, IVSigned, Ordered,
1569                              IL.getAddress(), LB.getAddress(),
1570                              UB.getAddress(), ST.getAddress());
1571         auto LoopExit =
1572             getJumpDestInCurrentScope(createBasicBlock("omp.loop.exit"));
1573         // UB = min(UB, GlobalUB);
1574         EmitIgnoredExpr(S.getEnsureUpperBound());
1575         // IV = LB;
1576         EmitIgnoredExpr(S.getInit());
1577         // while (idx <= UB) { BODY; ++idx; }
1578         EmitOMPInnerLoop(S, LoopScope.requiresCleanups(), S.getCond(),
1579                          S.getInc(),
1580                          [&S, LoopExit](CodeGenFunction &CGF) {
1581                            CGF.EmitOMPLoopBody(S, LoopExit);
1582                            CGF.EmitStopPoint(&S);
1583                          },
1584                          [](CodeGenFunction &) {});
1585         EmitBlock(LoopExit.getBlock());
1586         // Tell the runtime we are done.
1587         RT.emitForStaticFinish(*this, S.getLocStart());
1588       } else {
1589         const bool IsMonotonic = Ordered ||
1590                                  ScheduleKind == OMPC_SCHEDULE_static ||
1591                                  ScheduleKind == OMPC_SCHEDULE_unknown ||
1592                                  M1 == OMPC_SCHEDULE_MODIFIER_monotonic ||
1593                                  M2 == OMPC_SCHEDULE_MODIFIER_monotonic;
1594         // Emit the outer loop, which requests its work chunk [LB..UB] from
1595         // runtime and runs the inner loop to process it.
1596         EmitOMPForOuterLoop(ScheduleKind, IsMonotonic, S, LoopScope, Ordered,
1597                             LB.getAddress(), UB.getAddress(), ST.getAddress(),
1598                             IL.getAddress(), Chunk);
1599       }
1600       EmitOMPReductionClauseFinal(S);
1601       // Emit final copy of the lastprivate variables if IsLastIter != 0.
1602       if (HasLastprivateClause)
1603         EmitOMPLastprivateClauseFinal(
1604             S, Builder.CreateIsNotNull(EmitLoadOfScalar(IL, S.getLocStart())));
1605     }
1606     if (isOpenMPSimdDirective(S.getDirectiveKind())) {
1607       EmitOMPSimdFinal(S);
1608     }
1609     // We're now done with the loop, so jump to the continuation block.
1610     if (ContBlock) {
1611       EmitBranch(ContBlock);
1612       EmitBlock(ContBlock, true);
1613     }
1614   }
1615   return HasLastprivateClause;
1616 }
1617 
1618 void CodeGenFunction::EmitOMPForDirective(const OMPForDirective &S) {
1619   LexicalScope Scope(*this, S.getSourceRange());
1620   bool HasLastprivates = false;
1621   auto &&CodeGen = [&S, &HasLastprivates](CodeGenFunction &CGF) {
1622     HasLastprivates = CGF.EmitOMPWorksharingLoop(S);
1623   };
1624   CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_for, CodeGen,
1625                                               S.hasCancel());
1626 
1627   // Emit an implicit barrier at the end.
1628   if (!S.getSingleClause<OMPNowaitClause>() || HasLastprivates) {
1629     CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getLocStart(), OMPD_for);
1630   }
1631 }
1632 
1633 void CodeGenFunction::EmitOMPForSimdDirective(const OMPForSimdDirective &S) {
1634   LexicalScope Scope(*this, S.getSourceRange());
1635   bool HasLastprivates = false;
1636   auto &&CodeGen = [&S, &HasLastprivates](CodeGenFunction &CGF) {
1637     HasLastprivates = CGF.EmitOMPWorksharingLoop(S);
1638   };
1639   CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_simd, CodeGen);
1640 
1641   // Emit an implicit barrier at the end.
1642   if (!S.getSingleClause<OMPNowaitClause>() || HasLastprivates) {
1643     CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getLocStart(), OMPD_for);
1644   }
1645 }
1646 
1647 static LValue createSectionLVal(CodeGenFunction &CGF, QualType Ty,
1648                                 const Twine &Name,
1649                                 llvm::Value *Init = nullptr) {
1650   auto LVal = CGF.MakeAddrLValue(CGF.CreateMemTemp(Ty, Name), Ty);
1651   if (Init)
1652     CGF.EmitScalarInit(Init, LVal);
1653   return LVal;
1654 }
1655 
1656 OpenMPDirectiveKind
1657 CodeGenFunction::EmitSections(const OMPExecutableDirective &S) {
1658   auto *Stmt = cast<CapturedStmt>(S.getAssociatedStmt())->getCapturedStmt();
1659   auto *CS = dyn_cast<CompoundStmt>(Stmt);
1660   bool HasLastprivates = false;
1661   auto &&CodeGen = [&S, Stmt, CS, &HasLastprivates](CodeGenFunction &CGF) {
1662     auto &C = CGF.CGM.getContext();
1663     auto KmpInt32Ty = C.getIntTypeForBitwidth(/*DestWidth=*/32, /*Signed=*/1);
1664     // Emit helper vars inits.
1665     LValue LB = createSectionLVal(CGF, KmpInt32Ty, ".omp.sections.lb.",
1666                                   CGF.Builder.getInt32(0));
1667     auto *GlobalUBVal = CS != nullptr ? CGF.Builder.getInt32(CS->size() - 1)
1668                                       : CGF.Builder.getInt32(0);
1669     LValue UB =
1670         createSectionLVal(CGF, KmpInt32Ty, ".omp.sections.ub.", GlobalUBVal);
1671     LValue ST = createSectionLVal(CGF, KmpInt32Ty, ".omp.sections.st.",
1672                                   CGF.Builder.getInt32(1));
1673     LValue IL = createSectionLVal(CGF, KmpInt32Ty, ".omp.sections.il.",
1674                                   CGF.Builder.getInt32(0));
1675     // Loop counter.
1676     LValue IV = createSectionLVal(CGF, KmpInt32Ty, ".omp.sections.iv.");
1677     OpaqueValueExpr IVRefExpr(S.getLocStart(), KmpInt32Ty, VK_LValue);
1678     CodeGenFunction::OpaqueValueMapping OpaqueIV(CGF, &IVRefExpr, IV);
1679     OpaqueValueExpr UBRefExpr(S.getLocStart(), KmpInt32Ty, VK_LValue);
1680     CodeGenFunction::OpaqueValueMapping OpaqueUB(CGF, &UBRefExpr, UB);
1681     // Generate condition for loop.
1682     BinaryOperator Cond(&IVRefExpr, &UBRefExpr, BO_LE, C.BoolTy, VK_RValue,
1683                         OK_Ordinary, S.getLocStart(),
1684                         /*fpContractable=*/false);
1685     // Increment for loop counter.
1686     UnaryOperator Inc(&IVRefExpr, UO_PreInc, KmpInt32Ty, VK_RValue, OK_Ordinary,
1687                       S.getLocStart());
1688     auto BodyGen = [Stmt, CS, &S, &IV](CodeGenFunction &CGF) {
1689       // Iterate through all sections and emit a switch construct:
1690       // switch (IV) {
1691       //   case 0:
1692       //     <SectionStmt[0]>;
1693       //     break;
1694       // ...
1695       //   case <NumSection> - 1:
1696       //     <SectionStmt[<NumSection> - 1]>;
1697       //     break;
1698       // }
1699       // .omp.sections.exit:
1700       auto *ExitBB = CGF.createBasicBlock(".omp.sections.exit");
1701       auto *SwitchStmt = CGF.Builder.CreateSwitch(
1702           CGF.EmitLoadOfLValue(IV, S.getLocStart()).getScalarVal(), ExitBB,
1703           CS == nullptr ? 1 : CS->size());
1704       if (CS) {
1705         unsigned CaseNumber = 0;
1706         for (auto *SubStmt : CS->children()) {
1707           auto CaseBB = CGF.createBasicBlock(".omp.sections.case");
1708           CGF.EmitBlock(CaseBB);
1709           SwitchStmt->addCase(CGF.Builder.getInt32(CaseNumber), CaseBB);
1710           CGF.EmitStmt(SubStmt);
1711           CGF.EmitBranch(ExitBB);
1712           ++CaseNumber;
1713         }
1714       } else {
1715         auto CaseBB = CGF.createBasicBlock(".omp.sections.case");
1716         CGF.EmitBlock(CaseBB);
1717         SwitchStmt->addCase(CGF.Builder.getInt32(0), CaseBB);
1718         CGF.EmitStmt(Stmt);
1719         CGF.EmitBranch(ExitBB);
1720       }
1721       CGF.EmitBlock(ExitBB, /*IsFinished=*/true);
1722     };
1723 
1724     CodeGenFunction::OMPPrivateScope LoopScope(CGF);
1725     if (CGF.EmitOMPFirstprivateClause(S, LoopScope)) {
1726       // Emit implicit barrier to synchronize threads and avoid data races on
1727       // initialization of firstprivate variables.
1728       CGF.CGM.getOpenMPRuntime().emitBarrierCall(
1729           CGF, S.getLocStart(), OMPD_unknown, /*EmitChecks=*/false,
1730           /*ForceSimpleCall=*/true);
1731     }
1732     CGF.EmitOMPPrivateClause(S, LoopScope);
1733     HasLastprivates = CGF.EmitOMPLastprivateClauseInit(S, LoopScope);
1734     CGF.EmitOMPReductionClauseInit(S, LoopScope);
1735     (void)LoopScope.Privatize();
1736 
1737     // Emit static non-chunked loop.
1738     CGF.CGM.getOpenMPRuntime().emitForStaticInit(
1739         CGF, S.getLocStart(), OMPC_SCHEDULE_static, /*IVSize=*/32,
1740         /*IVSigned=*/true, /*Ordered=*/false, IL.getAddress(), LB.getAddress(),
1741         UB.getAddress(), ST.getAddress());
1742     // UB = min(UB, GlobalUB);
1743     auto *UBVal = CGF.EmitLoadOfScalar(UB, S.getLocStart());
1744     auto *MinUBGlobalUB = CGF.Builder.CreateSelect(
1745         CGF.Builder.CreateICmpSLT(UBVal, GlobalUBVal), UBVal, GlobalUBVal);
1746     CGF.EmitStoreOfScalar(MinUBGlobalUB, UB);
1747     // IV = LB;
1748     CGF.EmitStoreOfScalar(CGF.EmitLoadOfScalar(LB, S.getLocStart()), IV);
1749     // while (idx <= UB) { BODY; ++idx; }
1750     CGF.EmitOMPInnerLoop(S, /*RequiresCleanup=*/false, &Cond, &Inc, BodyGen,
1751                          [](CodeGenFunction &) {});
1752     // Tell the runtime we are done.
1753     CGF.CGM.getOpenMPRuntime().emitForStaticFinish(CGF, S.getLocStart());
1754     CGF.EmitOMPReductionClauseFinal(S);
1755 
1756     // Emit final copy of the lastprivate variables if IsLastIter != 0.
1757     if (HasLastprivates)
1758       CGF.EmitOMPLastprivateClauseFinal(
1759           S, CGF.Builder.CreateIsNotNull(
1760                  CGF.EmitLoadOfScalar(IL, S.getLocStart())));
1761   };
1762 
1763   bool HasCancel = false;
1764   if (auto *OSD = dyn_cast<OMPSectionsDirective>(&S))
1765     HasCancel = OSD->hasCancel();
1766   else if (auto *OPSD = dyn_cast<OMPParallelSectionsDirective>(&S))
1767     HasCancel = OPSD->hasCancel();
1768   CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_sections, CodeGen,
1769                                               HasCancel);
1770   // Emit barrier for lastprivates only if 'sections' directive has 'nowait'
1771   // clause. Otherwise the barrier will be generated by the codegen for the
1772   // directive.
1773   if (HasLastprivates && S.getSingleClause<OMPNowaitClause>()) {
1774     // Emit implicit barrier to synchronize threads and avoid data races on
1775     // initialization of firstprivate variables.
1776     CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getLocStart(),
1777                                            OMPD_unknown);
1778   }
1779   return OMPD_sections;
1780 }
1781 
1782 void CodeGenFunction::EmitOMPSectionsDirective(const OMPSectionsDirective &S) {
1783   LexicalScope Scope(*this, S.getSourceRange());
1784   OpenMPDirectiveKind EmittedAs = EmitSections(S);
1785   // Emit an implicit barrier at the end.
1786   if (!S.getSingleClause<OMPNowaitClause>()) {
1787     CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getLocStart(), EmittedAs);
1788   }
1789 }
1790 
1791 void CodeGenFunction::EmitOMPSectionDirective(const OMPSectionDirective &S) {
1792   LexicalScope Scope(*this, S.getSourceRange());
1793   auto &&CodeGen = [&S](CodeGenFunction &CGF) {
1794     CGF.EmitStmt(cast<CapturedStmt>(S.getAssociatedStmt())->getCapturedStmt());
1795   };
1796   CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_section, CodeGen,
1797                                               S.hasCancel());
1798 }
1799 
1800 void CodeGenFunction::EmitOMPSingleDirective(const OMPSingleDirective &S) {
1801   llvm::SmallVector<const Expr *, 8> CopyprivateVars;
1802   llvm::SmallVector<const Expr *, 8> DestExprs;
1803   llvm::SmallVector<const Expr *, 8> SrcExprs;
1804   llvm::SmallVector<const Expr *, 8> AssignmentOps;
1805   // Check if there are any 'copyprivate' clauses associated with this
1806   // 'single'
1807   // construct.
1808   // Build a list of copyprivate variables along with helper expressions
1809   // (<source>, <destination>, <destination>=<source> expressions)
1810   for (const auto *C : S.getClausesOfKind<OMPCopyprivateClause>()) {
1811     CopyprivateVars.append(C->varlists().begin(), C->varlists().end());
1812     DestExprs.append(C->destination_exprs().begin(),
1813                      C->destination_exprs().end());
1814     SrcExprs.append(C->source_exprs().begin(), C->source_exprs().end());
1815     AssignmentOps.append(C->assignment_ops().begin(),
1816                          C->assignment_ops().end());
1817   }
1818   LexicalScope Scope(*this, S.getSourceRange());
1819   // Emit code for 'single' region along with 'copyprivate' clauses
1820   bool HasFirstprivates;
1821   auto &&CodeGen = [&S, &HasFirstprivates](CodeGenFunction &CGF) {
1822     CodeGenFunction::OMPPrivateScope SingleScope(CGF);
1823     HasFirstprivates = CGF.EmitOMPFirstprivateClause(S, SingleScope);
1824     CGF.EmitOMPPrivateClause(S, SingleScope);
1825     (void)SingleScope.Privatize();
1826 
1827     CGF.EmitStmt(cast<CapturedStmt>(S.getAssociatedStmt())->getCapturedStmt());
1828   };
1829   CGM.getOpenMPRuntime().emitSingleRegion(*this, CodeGen, S.getLocStart(),
1830                                           CopyprivateVars, DestExprs, SrcExprs,
1831                                           AssignmentOps);
1832   // Emit an implicit barrier at the end (to avoid data race on firstprivate
1833   // init or if no 'nowait' clause was specified and no 'copyprivate' clause).
1834   if ((!S.getSingleClause<OMPNowaitClause>() || HasFirstprivates) &&
1835       CopyprivateVars.empty()) {
1836     CGM.getOpenMPRuntime().emitBarrierCall(
1837         *this, S.getLocStart(),
1838         S.getSingleClause<OMPNowaitClause>() ? OMPD_unknown : OMPD_single);
1839   }
1840 }
1841 
1842 void CodeGenFunction::EmitOMPMasterDirective(const OMPMasterDirective &S) {
1843   LexicalScope Scope(*this, S.getSourceRange());
1844   auto &&CodeGen = [&S](CodeGenFunction &CGF) {
1845     CGF.EmitStmt(cast<CapturedStmt>(S.getAssociatedStmt())->getCapturedStmt());
1846   };
1847   CGM.getOpenMPRuntime().emitMasterRegion(*this, CodeGen, S.getLocStart());
1848 }
1849 
1850 void CodeGenFunction::EmitOMPCriticalDirective(const OMPCriticalDirective &S) {
1851   LexicalScope Scope(*this, S.getSourceRange());
1852   auto &&CodeGen = [&S](CodeGenFunction &CGF) {
1853     CGF.EmitStmt(cast<CapturedStmt>(S.getAssociatedStmt())->getCapturedStmt());
1854   };
1855   Expr *Hint = nullptr;
1856   if (auto *HintClause = S.getSingleClause<OMPHintClause>())
1857     Hint = HintClause->getHint();
1858   CGM.getOpenMPRuntime().emitCriticalRegion(*this,
1859                                             S.getDirectiveName().getAsString(),
1860                                             CodeGen, S.getLocStart(), Hint);
1861 }
1862 
1863 void CodeGenFunction::EmitOMPParallelForDirective(
1864     const OMPParallelForDirective &S) {
1865   // Emit directive as a combined directive that consists of two implicit
1866   // directives: 'parallel' with 'for' directive.
1867   LexicalScope Scope(*this, S.getSourceRange());
1868   (void)emitScheduleClause(*this, S, /*OuterRegion=*/true);
1869   auto &&CodeGen = [&S](CodeGenFunction &CGF) {
1870     CGF.EmitOMPWorksharingLoop(S);
1871   };
1872   emitCommonOMPParallelDirective(*this, S, OMPD_for, CodeGen);
1873 }
1874 
1875 void CodeGenFunction::EmitOMPParallelForSimdDirective(
1876     const OMPParallelForSimdDirective &S) {
1877   // Emit directive as a combined directive that consists of two implicit
1878   // directives: 'parallel' with 'for' directive.
1879   LexicalScope Scope(*this, S.getSourceRange());
1880   (void)emitScheduleClause(*this, S, /*OuterRegion=*/true);
1881   auto &&CodeGen = [&S](CodeGenFunction &CGF) {
1882     CGF.EmitOMPWorksharingLoop(S);
1883   };
1884   emitCommonOMPParallelDirective(*this, S, OMPD_simd, CodeGen);
1885 }
1886 
1887 void CodeGenFunction::EmitOMPParallelSectionsDirective(
1888     const OMPParallelSectionsDirective &S) {
1889   // Emit directive as a combined directive that consists of two implicit
1890   // directives: 'parallel' with 'sections' directive.
1891   LexicalScope Scope(*this, S.getSourceRange());
1892   auto &&CodeGen = [&S](CodeGenFunction &CGF) {
1893     (void)CGF.EmitSections(S);
1894   };
1895   emitCommonOMPParallelDirective(*this, S, OMPD_sections, CodeGen);
1896 }
1897 
1898 void CodeGenFunction::EmitOMPTaskDirective(const OMPTaskDirective &S) {
1899   // Emit outlined function for task construct.
1900   LexicalScope Scope(*this, S.getSourceRange());
1901   auto CS = cast<CapturedStmt>(S.getAssociatedStmt());
1902   auto CapturedStruct = GenerateCapturedStmtArgument(*CS);
1903   auto *I = CS->getCapturedDecl()->param_begin();
1904   auto *PartId = std::next(I);
1905   // The first function argument for tasks is a thread id, the second one is a
1906   // part id (0 for tied tasks, >=0 for untied task).
1907   llvm::DenseSet<const VarDecl *> EmittedAsPrivate;
1908   // Get list of private variables.
1909   llvm::SmallVector<const Expr *, 8> PrivateVars;
1910   llvm::SmallVector<const Expr *, 8> PrivateCopies;
1911   for (const auto *C : S.getClausesOfKind<OMPPrivateClause>()) {
1912     auto IRef = C->varlist_begin();
1913     for (auto *IInit : C->private_copies()) {
1914       auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
1915       if (EmittedAsPrivate.insert(OrigVD->getCanonicalDecl()).second) {
1916         PrivateVars.push_back(*IRef);
1917         PrivateCopies.push_back(IInit);
1918       }
1919       ++IRef;
1920     }
1921   }
1922   EmittedAsPrivate.clear();
1923   // Get list of firstprivate variables.
1924   llvm::SmallVector<const Expr *, 8> FirstprivateVars;
1925   llvm::SmallVector<const Expr *, 8> FirstprivateCopies;
1926   llvm::SmallVector<const Expr *, 8> FirstprivateInits;
1927   for (const auto *C : S.getClausesOfKind<OMPFirstprivateClause>()) {
1928     auto IRef = C->varlist_begin();
1929     auto IElemInitRef = C->inits().begin();
1930     for (auto *IInit : C->private_copies()) {
1931       auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
1932       if (EmittedAsPrivate.insert(OrigVD->getCanonicalDecl()).second) {
1933         FirstprivateVars.push_back(*IRef);
1934         FirstprivateCopies.push_back(IInit);
1935         FirstprivateInits.push_back(*IElemInitRef);
1936       }
1937       ++IRef, ++IElemInitRef;
1938     }
1939   }
1940   // Build list of dependences.
1941   llvm::SmallVector<std::pair<OpenMPDependClauseKind, const Expr *>, 8>
1942       Dependences;
1943   for (const auto *C : S.getClausesOfKind<OMPDependClause>()) {
1944     for (auto *IRef : C->varlists()) {
1945       Dependences.push_back(std::make_pair(C->getDependencyKind(), IRef));
1946     }
1947   }
1948   auto &&CodeGen = [PartId, &S, &PrivateVars, &FirstprivateVars](
1949       CodeGenFunction &CGF) {
1950     // Set proper addresses for generated private copies.
1951     auto *CS = cast<CapturedStmt>(S.getAssociatedStmt());
1952     OMPPrivateScope Scope(CGF);
1953     if (!PrivateVars.empty() || !FirstprivateVars.empty()) {
1954       auto *CopyFn = CGF.Builder.CreateLoad(
1955           CGF.GetAddrOfLocalVar(CS->getCapturedDecl()->getParam(3)));
1956       auto *PrivatesPtr = CGF.Builder.CreateLoad(
1957           CGF.GetAddrOfLocalVar(CS->getCapturedDecl()->getParam(2)));
1958       // Map privates.
1959       llvm::SmallVector<std::pair<const VarDecl *, Address>, 16>
1960           PrivatePtrs;
1961       llvm::SmallVector<llvm::Value *, 16> CallArgs;
1962       CallArgs.push_back(PrivatesPtr);
1963       for (auto *E : PrivateVars) {
1964         auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
1965         Address PrivatePtr =
1966             CGF.CreateMemTemp(CGF.getContext().getPointerType(E->getType()));
1967         PrivatePtrs.push_back(std::make_pair(VD, PrivatePtr));
1968         CallArgs.push_back(PrivatePtr.getPointer());
1969       }
1970       for (auto *E : FirstprivateVars) {
1971         auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
1972         Address PrivatePtr =
1973             CGF.CreateMemTemp(CGF.getContext().getPointerType(E->getType()));
1974         PrivatePtrs.push_back(std::make_pair(VD, PrivatePtr));
1975         CallArgs.push_back(PrivatePtr.getPointer());
1976       }
1977       CGF.EmitRuntimeCall(CopyFn, CallArgs);
1978       for (auto &&Pair : PrivatePtrs) {
1979         Address Replacement(CGF.Builder.CreateLoad(Pair.second),
1980                             CGF.getContext().getDeclAlign(Pair.first));
1981         Scope.addPrivate(Pair.first, [Replacement]() { return Replacement; });
1982       }
1983     }
1984     (void)Scope.Privatize();
1985     if (*PartId) {
1986       // TODO: emit code for untied tasks.
1987     }
1988     CGF.EmitStmt(CS->getCapturedStmt());
1989   };
1990   auto OutlinedFn = CGM.getOpenMPRuntime().emitTaskOutlinedFunction(
1991       S, *I, OMPD_task, CodeGen);
1992   // Check if we should emit tied or untied task.
1993   bool Tied = !S.getSingleClause<OMPUntiedClause>();
1994   // Check if the task is final
1995   llvm::PointerIntPair<llvm::Value *, 1, bool> Final;
1996   if (const auto *Clause = S.getSingleClause<OMPFinalClause>()) {
1997     // If the condition constant folds and can be elided, try to avoid emitting
1998     // the condition and the dead arm of the if/else.
1999     auto *Cond = Clause->getCondition();
2000     bool CondConstant;
2001     if (ConstantFoldsToSimpleInteger(Cond, CondConstant))
2002       Final.setInt(CondConstant);
2003     else
2004       Final.setPointer(EvaluateExprAsBool(Cond));
2005   } else {
2006     // By default the task is not final.
2007     Final.setInt(/*IntVal=*/false);
2008   }
2009   auto SharedsTy = getContext().getRecordType(CS->getCapturedRecordDecl());
2010   const Expr *IfCond = nullptr;
2011   for (const auto *C : S.getClausesOfKind<OMPIfClause>()) {
2012     if (C->getNameModifier() == OMPD_unknown ||
2013         C->getNameModifier() == OMPD_task) {
2014       IfCond = C->getCondition();
2015       break;
2016     }
2017   }
2018   CGM.getOpenMPRuntime().emitTaskCall(
2019       *this, S.getLocStart(), S, Tied, Final, OutlinedFn, SharedsTy,
2020       CapturedStruct, IfCond, PrivateVars, PrivateCopies, FirstprivateVars,
2021       FirstprivateCopies, FirstprivateInits, Dependences);
2022 }
2023 
2024 void CodeGenFunction::EmitOMPTaskyieldDirective(
2025     const OMPTaskyieldDirective &S) {
2026   CGM.getOpenMPRuntime().emitTaskyieldCall(*this, S.getLocStart());
2027 }
2028 
2029 void CodeGenFunction::EmitOMPBarrierDirective(const OMPBarrierDirective &S) {
2030   CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getLocStart(), OMPD_barrier);
2031 }
2032 
2033 void CodeGenFunction::EmitOMPTaskwaitDirective(const OMPTaskwaitDirective &S) {
2034   CGM.getOpenMPRuntime().emitTaskwaitCall(*this, S.getLocStart());
2035 }
2036 
2037 void CodeGenFunction::EmitOMPTaskgroupDirective(
2038     const OMPTaskgroupDirective &S) {
2039   LexicalScope Scope(*this, S.getSourceRange());
2040   auto &&CodeGen = [&S](CodeGenFunction &CGF) {
2041     CGF.EmitStmt(cast<CapturedStmt>(S.getAssociatedStmt())->getCapturedStmt());
2042   };
2043   CGM.getOpenMPRuntime().emitTaskgroupRegion(*this, CodeGen, S.getLocStart());
2044 }
2045 
2046 void CodeGenFunction::EmitOMPFlushDirective(const OMPFlushDirective &S) {
2047   CGM.getOpenMPRuntime().emitFlush(*this, [&]() -> ArrayRef<const Expr *> {
2048     if (const auto *FlushClause = S.getSingleClause<OMPFlushClause>()) {
2049       return llvm::makeArrayRef(FlushClause->varlist_begin(),
2050                                 FlushClause->varlist_end());
2051     }
2052     return llvm::None;
2053   }(), S.getLocStart());
2054 }
2055 
2056 void CodeGenFunction::EmitOMPDistributeDirective(
2057     const OMPDistributeDirective &S) {
2058   llvm_unreachable("CodeGen for 'omp distribute' is not supported yet.");
2059 }
2060 
2061 static llvm::Function *emitOutlinedOrderedFunction(CodeGenModule &CGM,
2062                                                    const CapturedStmt *S) {
2063   CodeGenFunction CGF(CGM, /*suppressNewContext=*/true);
2064   CodeGenFunction::CGCapturedStmtInfo CapStmtInfo;
2065   CGF.CapturedStmtInfo = &CapStmtInfo;
2066   auto *Fn = CGF.GenerateOpenMPCapturedStmtFunction(*S);
2067   Fn->addFnAttr(llvm::Attribute::NoInline);
2068   return Fn;
2069 }
2070 
2071 void CodeGenFunction::EmitOMPOrderedDirective(const OMPOrderedDirective &S) {
2072   if (!S.getAssociatedStmt())
2073     return;
2074   LexicalScope Scope(*this, S.getSourceRange());
2075   auto *C = S.getSingleClause<OMPSIMDClause>();
2076   auto &&CodeGen = [&S, C, this](CodeGenFunction &CGF) {
2077     if (C) {
2078       auto CS = cast<CapturedStmt>(S.getAssociatedStmt());
2079       llvm::SmallVector<llvm::Value *, 16> CapturedVars;
2080       CGF.GenerateOpenMPCapturedVars(*CS, CapturedVars);
2081       auto *OutlinedFn = emitOutlinedOrderedFunction(CGM, CS);
2082       CGF.EmitNounwindRuntimeCall(OutlinedFn, CapturedVars);
2083     } else {
2084       CGF.EmitStmt(
2085           cast<CapturedStmt>(S.getAssociatedStmt())->getCapturedStmt());
2086     }
2087   };
2088   CGM.getOpenMPRuntime().emitOrderedRegion(*this, CodeGen, S.getLocStart(), !C);
2089 }
2090 
2091 static llvm::Value *convertToScalarValue(CodeGenFunction &CGF, RValue Val,
2092                                          QualType SrcType, QualType DestType,
2093                                          SourceLocation Loc) {
2094   assert(CGF.hasScalarEvaluationKind(DestType) &&
2095          "DestType must have scalar evaluation kind.");
2096   assert(!Val.isAggregate() && "Must be a scalar or complex.");
2097   return Val.isScalar()
2098              ? CGF.EmitScalarConversion(Val.getScalarVal(), SrcType, DestType,
2099                                         Loc)
2100              : CGF.EmitComplexToScalarConversion(Val.getComplexVal(), SrcType,
2101                                                  DestType, Loc);
2102 }
2103 
2104 static CodeGenFunction::ComplexPairTy
2105 convertToComplexValue(CodeGenFunction &CGF, RValue Val, QualType SrcType,
2106                       QualType DestType, SourceLocation Loc) {
2107   assert(CGF.getEvaluationKind(DestType) == TEK_Complex &&
2108          "DestType must have complex evaluation kind.");
2109   CodeGenFunction::ComplexPairTy ComplexVal;
2110   if (Val.isScalar()) {
2111     // Convert the input element to the element type of the complex.
2112     auto DestElementType = DestType->castAs<ComplexType>()->getElementType();
2113     auto ScalarVal = CGF.EmitScalarConversion(Val.getScalarVal(), SrcType,
2114                                               DestElementType, Loc);
2115     ComplexVal = CodeGenFunction::ComplexPairTy(
2116         ScalarVal, llvm::Constant::getNullValue(ScalarVal->getType()));
2117   } else {
2118     assert(Val.isComplex() && "Must be a scalar or complex.");
2119     auto SrcElementType = SrcType->castAs<ComplexType>()->getElementType();
2120     auto DestElementType = DestType->castAs<ComplexType>()->getElementType();
2121     ComplexVal.first = CGF.EmitScalarConversion(
2122         Val.getComplexVal().first, SrcElementType, DestElementType, Loc);
2123     ComplexVal.second = CGF.EmitScalarConversion(
2124         Val.getComplexVal().second, SrcElementType, DestElementType, Loc);
2125   }
2126   return ComplexVal;
2127 }
2128 
2129 static void emitSimpleAtomicStore(CodeGenFunction &CGF, bool IsSeqCst,
2130                                   LValue LVal, RValue RVal) {
2131   if (LVal.isGlobalReg()) {
2132     CGF.EmitStoreThroughGlobalRegLValue(RVal, LVal);
2133   } else {
2134     CGF.EmitAtomicStore(RVal, LVal, IsSeqCst ? llvm::SequentiallyConsistent
2135                                              : llvm::Monotonic,
2136                         LVal.isVolatile(), /*IsInit=*/false);
2137   }
2138 }
2139 
2140 void CodeGenFunction::emitOMPSimpleStore(LValue LVal, RValue RVal,
2141                                          QualType RValTy, SourceLocation Loc) {
2142   switch (getEvaluationKind(LVal.getType())) {
2143   case TEK_Scalar:
2144     EmitStoreThroughLValue(RValue::get(convertToScalarValue(
2145                                *this, RVal, RValTy, LVal.getType(), Loc)),
2146                            LVal);
2147     break;
2148   case TEK_Complex:
2149     EmitStoreOfComplex(
2150         convertToComplexValue(*this, RVal, RValTy, LVal.getType(), Loc), LVal,
2151         /*isInit=*/false);
2152     break;
2153   case TEK_Aggregate:
2154     llvm_unreachable("Must be a scalar or complex.");
2155   }
2156 }
2157 
2158 static void EmitOMPAtomicReadExpr(CodeGenFunction &CGF, bool IsSeqCst,
2159                                   const Expr *X, const Expr *V,
2160                                   SourceLocation Loc) {
2161   // v = x;
2162   assert(V->isLValue() && "V of 'omp atomic read' is not lvalue");
2163   assert(X->isLValue() && "X of 'omp atomic read' is not lvalue");
2164   LValue XLValue = CGF.EmitLValue(X);
2165   LValue VLValue = CGF.EmitLValue(V);
2166   RValue Res = XLValue.isGlobalReg()
2167                    ? CGF.EmitLoadOfLValue(XLValue, Loc)
2168                    : CGF.EmitAtomicLoad(XLValue, Loc,
2169                                         IsSeqCst ? llvm::SequentiallyConsistent
2170                                                  : llvm::Monotonic,
2171                                         XLValue.isVolatile());
2172   // OpenMP, 2.12.6, atomic Construct
2173   // Any atomic construct with a seq_cst clause forces the atomically
2174   // performed operation to include an implicit flush operation without a
2175   // list.
2176   if (IsSeqCst)
2177     CGF.CGM.getOpenMPRuntime().emitFlush(CGF, llvm::None, Loc);
2178   CGF.emitOMPSimpleStore(VLValue, Res, X->getType().getNonReferenceType(), Loc);
2179 }
2180 
2181 static void EmitOMPAtomicWriteExpr(CodeGenFunction &CGF, bool IsSeqCst,
2182                                    const Expr *X, const Expr *E,
2183                                    SourceLocation Loc) {
2184   // x = expr;
2185   assert(X->isLValue() && "X of 'omp atomic write' is not lvalue");
2186   emitSimpleAtomicStore(CGF, IsSeqCst, CGF.EmitLValue(X), CGF.EmitAnyExpr(E));
2187   // OpenMP, 2.12.6, atomic Construct
2188   // Any atomic construct with a seq_cst clause forces the atomically
2189   // performed operation to include an implicit flush operation without a
2190   // list.
2191   if (IsSeqCst)
2192     CGF.CGM.getOpenMPRuntime().emitFlush(CGF, llvm::None, Loc);
2193 }
2194 
2195 static std::pair<bool, RValue> emitOMPAtomicRMW(CodeGenFunction &CGF, LValue X,
2196                                                 RValue Update,
2197                                                 BinaryOperatorKind BO,
2198                                                 llvm::AtomicOrdering AO,
2199                                                 bool IsXLHSInRHSPart) {
2200   auto &Context = CGF.CGM.getContext();
2201   // Allow atomicrmw only if 'x' and 'update' are integer values, lvalue for 'x'
2202   // expression is simple and atomic is allowed for the given type for the
2203   // target platform.
2204   if (BO == BO_Comma || !Update.isScalar() ||
2205       !Update.getScalarVal()->getType()->isIntegerTy() ||
2206       !X.isSimple() || (!isa<llvm::ConstantInt>(Update.getScalarVal()) &&
2207                         (Update.getScalarVal()->getType() !=
2208                          X.getAddress().getElementType())) ||
2209       !X.getAddress().getElementType()->isIntegerTy() ||
2210       !Context.getTargetInfo().hasBuiltinAtomic(
2211           Context.getTypeSize(X.getType()), Context.toBits(X.getAlignment())))
2212     return std::make_pair(false, RValue::get(nullptr));
2213 
2214   llvm::AtomicRMWInst::BinOp RMWOp;
2215   switch (BO) {
2216   case BO_Add:
2217     RMWOp = llvm::AtomicRMWInst::Add;
2218     break;
2219   case BO_Sub:
2220     if (!IsXLHSInRHSPart)
2221       return std::make_pair(false, RValue::get(nullptr));
2222     RMWOp = llvm::AtomicRMWInst::Sub;
2223     break;
2224   case BO_And:
2225     RMWOp = llvm::AtomicRMWInst::And;
2226     break;
2227   case BO_Or:
2228     RMWOp = llvm::AtomicRMWInst::Or;
2229     break;
2230   case BO_Xor:
2231     RMWOp = llvm::AtomicRMWInst::Xor;
2232     break;
2233   case BO_LT:
2234     RMWOp = X.getType()->hasSignedIntegerRepresentation()
2235                 ? (IsXLHSInRHSPart ? llvm::AtomicRMWInst::Min
2236                                    : llvm::AtomicRMWInst::Max)
2237                 : (IsXLHSInRHSPart ? llvm::AtomicRMWInst::UMin
2238                                    : llvm::AtomicRMWInst::UMax);
2239     break;
2240   case BO_GT:
2241     RMWOp = X.getType()->hasSignedIntegerRepresentation()
2242                 ? (IsXLHSInRHSPart ? llvm::AtomicRMWInst::Max
2243                                    : llvm::AtomicRMWInst::Min)
2244                 : (IsXLHSInRHSPart ? llvm::AtomicRMWInst::UMax
2245                                    : llvm::AtomicRMWInst::UMin);
2246     break;
2247   case BO_Assign:
2248     RMWOp = llvm::AtomicRMWInst::Xchg;
2249     break;
2250   case BO_Mul:
2251   case BO_Div:
2252   case BO_Rem:
2253   case BO_Shl:
2254   case BO_Shr:
2255   case BO_LAnd:
2256   case BO_LOr:
2257     return std::make_pair(false, RValue::get(nullptr));
2258   case BO_PtrMemD:
2259   case BO_PtrMemI:
2260   case BO_LE:
2261   case BO_GE:
2262   case BO_EQ:
2263   case BO_NE:
2264   case BO_AddAssign:
2265   case BO_SubAssign:
2266   case BO_AndAssign:
2267   case BO_OrAssign:
2268   case BO_XorAssign:
2269   case BO_MulAssign:
2270   case BO_DivAssign:
2271   case BO_RemAssign:
2272   case BO_ShlAssign:
2273   case BO_ShrAssign:
2274   case BO_Comma:
2275     llvm_unreachable("Unsupported atomic update operation");
2276   }
2277   auto *UpdateVal = Update.getScalarVal();
2278   if (auto *IC = dyn_cast<llvm::ConstantInt>(UpdateVal)) {
2279     UpdateVal = CGF.Builder.CreateIntCast(
2280         IC, X.getAddress().getElementType(),
2281         X.getType()->hasSignedIntegerRepresentation());
2282   }
2283   auto *Res = CGF.Builder.CreateAtomicRMW(RMWOp, X.getPointer(), UpdateVal, AO);
2284   return std::make_pair(true, RValue::get(Res));
2285 }
2286 
2287 std::pair<bool, RValue> CodeGenFunction::EmitOMPAtomicSimpleUpdateExpr(
2288     LValue X, RValue E, BinaryOperatorKind BO, bool IsXLHSInRHSPart,
2289     llvm::AtomicOrdering AO, SourceLocation Loc,
2290     const llvm::function_ref<RValue(RValue)> &CommonGen) {
2291   // Update expressions are allowed to have the following forms:
2292   // x binop= expr; -> xrval + expr;
2293   // x++, ++x -> xrval + 1;
2294   // x--, --x -> xrval - 1;
2295   // x = x binop expr; -> xrval binop expr
2296   // x = expr Op x; - > expr binop xrval;
2297   auto Res = emitOMPAtomicRMW(*this, X, E, BO, AO, IsXLHSInRHSPart);
2298   if (!Res.first) {
2299     if (X.isGlobalReg()) {
2300       // Emit an update expression: 'xrval' binop 'expr' or 'expr' binop
2301       // 'xrval'.
2302       EmitStoreThroughLValue(CommonGen(EmitLoadOfLValue(X, Loc)), X);
2303     } else {
2304       // Perform compare-and-swap procedure.
2305       EmitAtomicUpdate(X, AO, CommonGen, X.getType().isVolatileQualified());
2306     }
2307   }
2308   return Res;
2309 }
2310 
2311 static void EmitOMPAtomicUpdateExpr(CodeGenFunction &CGF, bool IsSeqCst,
2312                                     const Expr *X, const Expr *E,
2313                                     const Expr *UE, bool IsXLHSInRHSPart,
2314                                     SourceLocation Loc) {
2315   assert(isa<BinaryOperator>(UE->IgnoreImpCasts()) &&
2316          "Update expr in 'atomic update' must be a binary operator.");
2317   auto *BOUE = cast<BinaryOperator>(UE->IgnoreImpCasts());
2318   // Update expressions are allowed to have the following forms:
2319   // x binop= expr; -> xrval + expr;
2320   // x++, ++x -> xrval + 1;
2321   // x--, --x -> xrval - 1;
2322   // x = x binop expr; -> xrval binop expr
2323   // x = expr Op x; - > expr binop xrval;
2324   assert(X->isLValue() && "X of 'omp atomic update' is not lvalue");
2325   LValue XLValue = CGF.EmitLValue(X);
2326   RValue ExprRValue = CGF.EmitAnyExpr(E);
2327   auto AO = IsSeqCst ? llvm::SequentiallyConsistent : llvm::Monotonic;
2328   auto *LHS = cast<OpaqueValueExpr>(BOUE->getLHS()->IgnoreImpCasts());
2329   auto *RHS = cast<OpaqueValueExpr>(BOUE->getRHS()->IgnoreImpCasts());
2330   auto *XRValExpr = IsXLHSInRHSPart ? LHS : RHS;
2331   auto *ERValExpr = IsXLHSInRHSPart ? RHS : LHS;
2332   auto Gen =
2333       [&CGF, UE, ExprRValue, XRValExpr, ERValExpr](RValue XRValue) -> RValue {
2334         CodeGenFunction::OpaqueValueMapping MapExpr(CGF, ERValExpr, ExprRValue);
2335         CodeGenFunction::OpaqueValueMapping MapX(CGF, XRValExpr, XRValue);
2336         return CGF.EmitAnyExpr(UE);
2337       };
2338   (void)CGF.EmitOMPAtomicSimpleUpdateExpr(
2339       XLValue, ExprRValue, BOUE->getOpcode(), IsXLHSInRHSPart, AO, Loc, Gen);
2340   // OpenMP, 2.12.6, atomic Construct
2341   // Any atomic construct with a seq_cst clause forces the atomically
2342   // performed operation to include an implicit flush operation without a
2343   // list.
2344   if (IsSeqCst)
2345     CGF.CGM.getOpenMPRuntime().emitFlush(CGF, llvm::None, Loc);
2346 }
2347 
2348 static RValue convertToType(CodeGenFunction &CGF, RValue Value,
2349                             QualType SourceType, QualType ResType,
2350                             SourceLocation Loc) {
2351   switch (CGF.getEvaluationKind(ResType)) {
2352   case TEK_Scalar:
2353     return RValue::get(
2354         convertToScalarValue(CGF, Value, SourceType, ResType, Loc));
2355   case TEK_Complex: {
2356     auto Res = convertToComplexValue(CGF, Value, SourceType, ResType, Loc);
2357     return RValue::getComplex(Res.first, Res.second);
2358   }
2359   case TEK_Aggregate:
2360     break;
2361   }
2362   llvm_unreachable("Must be a scalar or complex.");
2363 }
2364 
2365 static void EmitOMPAtomicCaptureExpr(CodeGenFunction &CGF, bool IsSeqCst,
2366                                      bool IsPostfixUpdate, const Expr *V,
2367                                      const Expr *X, const Expr *E,
2368                                      const Expr *UE, bool IsXLHSInRHSPart,
2369                                      SourceLocation Loc) {
2370   assert(X->isLValue() && "X of 'omp atomic capture' is not lvalue");
2371   assert(V->isLValue() && "V of 'omp atomic capture' is not lvalue");
2372   RValue NewVVal;
2373   LValue VLValue = CGF.EmitLValue(V);
2374   LValue XLValue = CGF.EmitLValue(X);
2375   RValue ExprRValue = CGF.EmitAnyExpr(E);
2376   auto AO = IsSeqCst ? llvm::SequentiallyConsistent : llvm::Monotonic;
2377   QualType NewVValType;
2378   if (UE) {
2379     // 'x' is updated with some additional value.
2380     assert(isa<BinaryOperator>(UE->IgnoreImpCasts()) &&
2381            "Update expr in 'atomic capture' must be a binary operator.");
2382     auto *BOUE = cast<BinaryOperator>(UE->IgnoreImpCasts());
2383     // Update expressions are allowed to have the following forms:
2384     // x binop= expr; -> xrval + expr;
2385     // x++, ++x -> xrval + 1;
2386     // x--, --x -> xrval - 1;
2387     // x = x binop expr; -> xrval binop expr
2388     // x = expr Op x; - > expr binop xrval;
2389     auto *LHS = cast<OpaqueValueExpr>(BOUE->getLHS()->IgnoreImpCasts());
2390     auto *RHS = cast<OpaqueValueExpr>(BOUE->getRHS()->IgnoreImpCasts());
2391     auto *XRValExpr = IsXLHSInRHSPart ? LHS : RHS;
2392     NewVValType = XRValExpr->getType();
2393     auto *ERValExpr = IsXLHSInRHSPart ? RHS : LHS;
2394     auto &&Gen = [&CGF, &NewVVal, UE, ExprRValue, XRValExpr, ERValExpr,
2395                   IsSeqCst, IsPostfixUpdate](RValue XRValue) -> RValue {
2396       CodeGenFunction::OpaqueValueMapping MapExpr(CGF, ERValExpr, ExprRValue);
2397       CodeGenFunction::OpaqueValueMapping MapX(CGF, XRValExpr, XRValue);
2398       RValue Res = CGF.EmitAnyExpr(UE);
2399       NewVVal = IsPostfixUpdate ? XRValue : Res;
2400       return Res;
2401     };
2402     auto Res = CGF.EmitOMPAtomicSimpleUpdateExpr(
2403         XLValue, ExprRValue, BOUE->getOpcode(), IsXLHSInRHSPart, AO, Loc, Gen);
2404     if (Res.first) {
2405       // 'atomicrmw' instruction was generated.
2406       if (IsPostfixUpdate) {
2407         // Use old value from 'atomicrmw'.
2408         NewVVal = Res.second;
2409       } else {
2410         // 'atomicrmw' does not provide new value, so evaluate it using old
2411         // value of 'x'.
2412         CodeGenFunction::OpaqueValueMapping MapExpr(CGF, ERValExpr, ExprRValue);
2413         CodeGenFunction::OpaqueValueMapping MapX(CGF, XRValExpr, Res.second);
2414         NewVVal = CGF.EmitAnyExpr(UE);
2415       }
2416     }
2417   } else {
2418     // 'x' is simply rewritten with some 'expr'.
2419     NewVValType = X->getType().getNonReferenceType();
2420     ExprRValue = convertToType(CGF, ExprRValue, E->getType(),
2421                                X->getType().getNonReferenceType(), Loc);
2422     auto &&Gen = [&CGF, &NewVVal, ExprRValue](RValue XRValue) -> RValue {
2423       NewVVal = XRValue;
2424       return ExprRValue;
2425     };
2426     // Try to perform atomicrmw xchg, otherwise simple exchange.
2427     auto Res = CGF.EmitOMPAtomicSimpleUpdateExpr(
2428         XLValue, ExprRValue, /*BO=*/BO_Assign, /*IsXLHSInRHSPart=*/false, AO,
2429         Loc, Gen);
2430     if (Res.first) {
2431       // 'atomicrmw' instruction was generated.
2432       NewVVal = IsPostfixUpdate ? Res.second : ExprRValue;
2433     }
2434   }
2435   // Emit post-update store to 'v' of old/new 'x' value.
2436   CGF.emitOMPSimpleStore(VLValue, NewVVal, NewVValType, Loc);
2437   // OpenMP, 2.12.6, atomic Construct
2438   // Any atomic construct with a seq_cst clause forces the atomically
2439   // performed operation to include an implicit flush operation without a
2440   // list.
2441   if (IsSeqCst)
2442     CGF.CGM.getOpenMPRuntime().emitFlush(CGF, llvm::None, Loc);
2443 }
2444 
2445 static void EmitOMPAtomicExpr(CodeGenFunction &CGF, OpenMPClauseKind Kind,
2446                               bool IsSeqCst, bool IsPostfixUpdate,
2447                               const Expr *X, const Expr *V, const Expr *E,
2448                               const Expr *UE, bool IsXLHSInRHSPart,
2449                               SourceLocation Loc) {
2450   switch (Kind) {
2451   case OMPC_read:
2452     EmitOMPAtomicReadExpr(CGF, IsSeqCst, X, V, Loc);
2453     break;
2454   case OMPC_write:
2455     EmitOMPAtomicWriteExpr(CGF, IsSeqCst, X, E, Loc);
2456     break;
2457   case OMPC_unknown:
2458   case OMPC_update:
2459     EmitOMPAtomicUpdateExpr(CGF, IsSeqCst, X, E, UE, IsXLHSInRHSPart, Loc);
2460     break;
2461   case OMPC_capture:
2462     EmitOMPAtomicCaptureExpr(CGF, IsSeqCst, IsPostfixUpdate, V, X, E, UE,
2463                              IsXLHSInRHSPart, Loc);
2464     break;
2465   case OMPC_if:
2466   case OMPC_final:
2467   case OMPC_num_threads:
2468   case OMPC_private:
2469   case OMPC_firstprivate:
2470   case OMPC_lastprivate:
2471   case OMPC_reduction:
2472   case OMPC_safelen:
2473   case OMPC_simdlen:
2474   case OMPC_collapse:
2475   case OMPC_default:
2476   case OMPC_seq_cst:
2477   case OMPC_shared:
2478   case OMPC_linear:
2479   case OMPC_aligned:
2480   case OMPC_copyin:
2481   case OMPC_copyprivate:
2482   case OMPC_flush:
2483   case OMPC_proc_bind:
2484   case OMPC_schedule:
2485   case OMPC_ordered:
2486   case OMPC_nowait:
2487   case OMPC_untied:
2488   case OMPC_threadprivate:
2489   case OMPC_depend:
2490   case OMPC_mergeable:
2491   case OMPC_device:
2492   case OMPC_threads:
2493   case OMPC_simd:
2494   case OMPC_map:
2495   case OMPC_num_teams:
2496   case OMPC_thread_limit:
2497   case OMPC_priority:
2498   case OMPC_grainsize:
2499   case OMPC_nogroup:
2500   case OMPC_num_tasks:
2501   case OMPC_hint:
2502   case OMPC_dist_schedule:
2503     llvm_unreachable("Clause is not allowed in 'omp atomic'.");
2504   }
2505 }
2506 
2507 void CodeGenFunction::EmitOMPAtomicDirective(const OMPAtomicDirective &S) {
2508   bool IsSeqCst = S.getSingleClause<OMPSeqCstClause>();
2509   OpenMPClauseKind Kind = OMPC_unknown;
2510   for (auto *C : S.clauses()) {
2511     // Find first clause (skip seq_cst clause, if it is first).
2512     if (C->getClauseKind() != OMPC_seq_cst) {
2513       Kind = C->getClauseKind();
2514       break;
2515     }
2516   }
2517 
2518   const auto *CS =
2519       S.getAssociatedStmt()->IgnoreContainers(/*IgnoreCaptured=*/true);
2520   if (const auto *EWC = dyn_cast<ExprWithCleanups>(CS)) {
2521     enterFullExpression(EWC);
2522   }
2523   // Processing for statements under 'atomic capture'.
2524   if (const auto *Compound = dyn_cast<CompoundStmt>(CS)) {
2525     for (const auto *C : Compound->body()) {
2526       if (const auto *EWC = dyn_cast<ExprWithCleanups>(C)) {
2527         enterFullExpression(EWC);
2528       }
2529     }
2530   }
2531 
2532   LexicalScope Scope(*this, S.getSourceRange());
2533   auto &&CodeGen = [&S, Kind, IsSeqCst, CS](CodeGenFunction &CGF) {
2534     CGF.EmitStopPoint(CS);
2535     EmitOMPAtomicExpr(CGF, Kind, IsSeqCst, S.isPostfixUpdate(), S.getX(),
2536                       S.getV(), S.getExpr(), S.getUpdateExpr(),
2537                       S.isXLHSInRHSPart(), S.getLocStart());
2538   };
2539   CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_atomic, CodeGen);
2540 }
2541 
2542 void CodeGenFunction::EmitOMPTargetDirective(const OMPTargetDirective &S) {
2543   LexicalScope Scope(*this, S.getSourceRange());
2544   const CapturedStmt &CS = *cast<CapturedStmt>(S.getAssociatedStmt());
2545 
2546   llvm::SmallVector<llvm::Value *, 16> CapturedVars;
2547   GenerateOpenMPCapturedVars(CS, CapturedVars);
2548 
2549   llvm::Function *Fn = nullptr;
2550   llvm::Constant *FnID = nullptr;
2551 
2552   // Check if we have any if clause associated with the directive.
2553   const Expr *IfCond = nullptr;
2554 
2555   if (auto *C = S.getSingleClause<OMPIfClause>()) {
2556     IfCond = C->getCondition();
2557   }
2558 
2559   // Check if we have any device clause associated with the directive.
2560   const Expr *Device = nullptr;
2561   if (auto *C = S.getSingleClause<OMPDeviceClause>()) {
2562     Device = C->getDevice();
2563   }
2564 
2565   // Check if we have an if clause whose conditional always evaluates to false
2566   // or if we do not have any targets specified. If so the target region is not
2567   // an offload entry point.
2568   bool IsOffloadEntry = true;
2569   if (IfCond) {
2570     bool Val;
2571     if (ConstantFoldsToSimpleInteger(IfCond, Val) && !Val)
2572       IsOffloadEntry = false;
2573   }
2574   if (CGM.getLangOpts().OMPTargetTriples.empty())
2575     IsOffloadEntry = false;
2576 
2577   assert(CurFuncDecl && "No parent declaration for target region!");
2578   StringRef ParentName;
2579   // In case we have Ctors/Dtors we use the complete type variant to produce
2580   // the mangling of the device outlined kernel.
2581   if (auto *D = dyn_cast<CXXConstructorDecl>(CurFuncDecl))
2582     ParentName = CGM.getMangledName(GlobalDecl(D, Ctor_Complete));
2583   else if (auto *D = dyn_cast<CXXDestructorDecl>(CurFuncDecl))
2584     ParentName = CGM.getMangledName(GlobalDecl(D, Dtor_Complete));
2585   else
2586     ParentName =
2587         CGM.getMangledName(GlobalDecl(cast<FunctionDecl>(CurFuncDecl)));
2588 
2589   CGM.getOpenMPRuntime().emitTargetOutlinedFunction(S, ParentName, Fn, FnID,
2590                                                     IsOffloadEntry);
2591 
2592   CGM.getOpenMPRuntime().emitTargetCall(*this, S, Fn, FnID, IfCond, Device,
2593                                         CapturedVars);
2594 }
2595 
2596 void CodeGenFunction::EmitOMPTeamsDirective(const OMPTeamsDirective &) {
2597   llvm_unreachable("CodeGen for 'omp teams' is not supported yet.");
2598 }
2599 
2600 void CodeGenFunction::EmitOMPCancellationPointDirective(
2601     const OMPCancellationPointDirective &S) {
2602   CGM.getOpenMPRuntime().emitCancellationPointCall(*this, S.getLocStart(),
2603                                                    S.getCancelRegion());
2604 }
2605 
2606 void CodeGenFunction::EmitOMPCancelDirective(const OMPCancelDirective &S) {
2607   const Expr *IfCond = nullptr;
2608   for (const auto *C : S.getClausesOfKind<OMPIfClause>()) {
2609     if (C->getNameModifier() == OMPD_unknown ||
2610         C->getNameModifier() == OMPD_cancel) {
2611       IfCond = C->getCondition();
2612       break;
2613     }
2614   }
2615   CGM.getOpenMPRuntime().emitCancelCall(*this, S.getLocStart(), IfCond,
2616                                         S.getCancelRegion());
2617 }
2618 
2619 CodeGenFunction::JumpDest
2620 CodeGenFunction::getOMPCancelDestination(OpenMPDirectiveKind Kind) {
2621   if (Kind == OMPD_parallel || Kind == OMPD_task)
2622     return ReturnBlock;
2623   assert(Kind == OMPD_for || Kind == OMPD_section || Kind == OMPD_sections ||
2624          Kind == OMPD_parallel_sections || Kind == OMPD_parallel_for);
2625   return BreakContinueStack.back().BreakBlock;
2626 }
2627 
2628 // Generate the instructions for '#pragma omp target data' directive.
2629 void CodeGenFunction::EmitOMPTargetDataDirective(
2630     const OMPTargetDataDirective &S) {
2631   // emit the code inside the construct for now
2632   auto CS = cast<CapturedStmt>(S.getAssociatedStmt());
2633   CGM.getOpenMPRuntime().emitInlinedDirective(
2634       *this, OMPD_target_data,
2635       [&CS](CodeGenFunction &CGF) { CGF.EmitStmt(CS->getCapturedStmt()); });
2636 }
2637 
2638 void CodeGenFunction::EmitOMPTargetEnterDataDirective(
2639     const OMPTargetEnterDataDirective &S) {
2640   // TODO: codegen for target enter data.
2641 }
2642 
2643 void CodeGenFunction::EmitOMPTargetExitDataDirective(
2644     const OMPTargetExitDataDirective &S) {
2645   // TODO: codegen for target exit data.
2646 }
2647 
2648 void CodeGenFunction::EmitOMPTaskLoopDirective(const OMPTaskLoopDirective &S) {
2649   // emit the code inside the construct for now
2650   auto CS = cast<CapturedStmt>(S.getAssociatedStmt());
2651   CGM.getOpenMPRuntime().emitInlinedDirective(
2652       *this, OMPD_taskloop,
2653       [&CS](CodeGenFunction &CGF) { CGF.EmitStmt(CS->getCapturedStmt()); });
2654 }
2655 
2656 void CodeGenFunction::EmitOMPTaskLoopSimdDirective(
2657     const OMPTaskLoopSimdDirective &S) {
2658   // emit the code inside the construct for now
2659   auto CS = cast<CapturedStmt>(S.getAssociatedStmt());
2660   CGM.getOpenMPRuntime().emitInlinedDirective(
2661       *this, OMPD_taskloop_simd,
2662       [&CS](CodeGenFunction &CGF) { CGF.EmitStmt(CS->getCapturedStmt()); });
2663 }
2664 
2665