lib/CodeGen/CGStmtOpenMP.cpp

//===--- CGStmtOpenMP.cpp - Emit LLVM Code from Statements ----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This contains code to emit OpenMP nodes as LLVM code.
//
//===----------------------------------------------------------------------===//

#include "CGCleanup.h"
#include "CGOpenMPRuntime.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "TargetInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Stmt.h"
#include "clang/AST/StmtOpenMP.h"
#include "clang/AST/DeclOpenMP.h"
#include "clang/Basic/PrettyStackTrace.h"
using namespace clang;
using namespace CodeGen;

namespace {
/// Lexical scope for OpenMP executable constructs, that handles correct codegen
/// for captured expressions.
class OMPLexicalScope : public CodeGenFunction::LexicalScope {
  void emitPreInitStmt(CodeGenFunction &CGF, const OMPExecutableDirective &S) {
    for (const auto *C : S.clauses()) {
      if (const auto *CPI = OMPClauseWithPreInit::get(C)) {
        if (const auto *PreInit =
                cast_or_null<DeclStmt>(CPI->getPreInitStmt())) {
          for (const auto *I : PreInit->decls()) {
            if (!I->hasAttr<OMPCaptureNoInitAttr>()) {
              CGF.EmitVarDecl(cast<VarDecl>(*I));
            } else {
              CodeGenFunction::AutoVarEmission Emission =
                  CGF.EmitAutoVarAlloca(cast<VarDecl>(*I));
              CGF.EmitAutoVarCleanups(Emission);
            }
          }
        }
      }
    }
  }
  CodeGenFunction::OMPPrivateScope InlinedShareds;

  static bool isCapturedVar(CodeGenFunction &CGF, const VarDecl *VD) {
    return CGF.LambdaCaptureFields.lookup(VD) ||
           (CGF.CapturedStmtInfo && CGF.CapturedStmtInfo->lookup(VD)) ||
           (CGF.CurCodeDecl && isa<BlockDecl>(CGF.CurCodeDecl));
  }

public:
  OMPLexicalScope(
      CodeGenFunction &CGF, const OMPExecutableDirective &S,
      const llvm::Optional<OpenMPDirectiveKind> CapturedRegion = llvm::None,
      const bool EmitPreInitStmt = true)
      : CodeGenFunction::LexicalScope(CGF, S.getSourceRange()),
        InlinedShareds(CGF) {
    if (EmitPreInitStmt)
      emitPreInitStmt(CGF, S);
    if (!CapturedRegion.hasValue())
      return;
    assert(S.hasAssociatedStmt() &&
           "Expected associated statement for inlined directive.");
    const CapturedStmt *CS = S.getCapturedStmt(*CapturedRegion);
    for (const auto &C : CS->captures()) {
      if (C.capturesVariable() || C.capturesVariableByCopy()) {
        auto *VD = C.getCapturedVar();
        assert(VD == VD->getCanonicalDecl() &&
               "Canonical decl must be captured.");
        DeclRefExpr DRE(
            CGF.getContext(), const_cast<VarDecl *>(VD),
            isCapturedVar(CGF, VD) || (CGF.CapturedStmtInfo &&
                                       InlinedShareds.isGlobalVarCaptured(VD)),
            VD->getType().getNonReferenceType(), VK_LValue, C.getLocation());
        InlinedShareds.addPrivate(VD, [&CGF, &DRE]() -> Address {
          return CGF.EmitLValue(&DRE).getAddress(CGF);
        });
      }
    }
    (void)InlinedShareds.Privatize();
  }
};

/// Lexical scope for OpenMP parallel construct, that handles correct codegen
/// for captured expressions.
class OMPParallelScope final : public OMPLexicalScope {
  bool EmitPreInitStmt(const OMPExecutableDirective &S) {
    OpenMPDirectiveKind Kind = S.getDirectiveKind();
    return !(isOpenMPTargetExecutionDirective(Kind) ||
             isOpenMPLoopBoundSharingDirective(Kind)) &&
           isOpenMPParallelDirective(Kind);
  }

public:
  OMPParallelScope(CodeGenFunction &CGF, const OMPExecutableDirective &S)
      : OMPLexicalScope(CGF, S, /*CapturedRegion=*/llvm::None,
                        EmitPreInitStmt(S)) {}
};

/// Lexical scope for OpenMP teams construct, that handles correct codegen
/// for captured expressions.
class OMPTeamsScope final : public OMPLexicalScope {
  bool EmitPreInitStmt(const OMPExecutableDirective &S) {
    OpenMPDirectiveKind Kind = S.getDirectiveKind();
    return !isOpenMPTargetExecutionDirective(Kind) &&
           isOpenMPTeamsDirective(Kind);
  }

public:
  OMPTeamsScope(CodeGenFunction &CGF, const OMPExecutableDirective &S)
      : OMPLexicalScope(CGF, S, /*CapturedRegion=*/llvm::None,
                        EmitPreInitStmt(S)) {}
};

/// Private scope for OpenMP loop-based directives, that supports capturing
/// of used expression from loop statement.
class OMPLoopScope : public CodeGenFunction::RunCleanupsScope {
  void emitPreInitStmt(CodeGenFunction &CGF, const OMPLoopDirective &S) {
    CodeGenFunction::OMPMapVars PreCondVars;
    llvm::DenseSet<const VarDecl *> EmittedAsPrivate;
    for (const auto *E : S.counters()) {
      const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
      EmittedAsPrivate.insert(VD->getCanonicalDecl());
      (void)PreCondVars.setVarAddr(
          CGF, VD, CGF.CreateMemTemp(VD->getType().getNonReferenceType()));
    }
    // Mark private vars as undefs.
    for (const auto *C : S.getClausesOfKind<OMPPrivateClause>()) {
      for (const Expr *IRef : C->varlists()) {
        const auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(IRef)->getDecl());
        if (EmittedAsPrivate.insert(OrigVD->getCanonicalDecl()).second) {
          (void)PreCondVars.setVarAddr(
              CGF, OrigVD,
              Address(llvm::UndefValue::get(
                          CGF.ConvertTypeForMem(CGF.getContext().getPointerType(
                              OrigVD->getType().getNonReferenceType()))),
                      CGF.getContext().getDeclAlign(OrigVD)));
        }
      }
    }
    (void)PreCondVars.apply(CGF);
    // Emit init, __range and __end variables for C++ range loops.
    const Stmt *Body =
        S.getInnermostCapturedStmt()->getCapturedStmt()->IgnoreContainers();
    for (unsigned Cnt = 0; Cnt < S.getCollapsedNumber(); ++Cnt) {
      Body = OMPLoopDirective::tryToFindNextInnerLoop(
          Body, /*TryImperfectlyNestedLoops=*/true);
      if (auto *For = dyn_cast<ForStmt>(Body)) {
        Body = For->getBody();
      } else {
        assert(isa<CXXForRangeStmt>(Body) &&
               "Expected canonical for loop or range-based for loop.");
        auto *CXXFor = cast<CXXForRangeStmt>(Body);
        if (const Stmt *Init = CXXFor->getInit())
          CGF.EmitStmt(Init);
        CGF.EmitStmt(CXXFor->getRangeStmt());
        CGF.EmitStmt(CXXFor->getEndStmt());
        Body = CXXFor->getBody();
      }
    }
    if (const auto *PreInits = cast_or_null<DeclStmt>(S.getPreInits())) {
      for (const auto *I : PreInits->decls())
        CGF.EmitVarDecl(cast<VarDecl>(*I));
    }
    PreCondVars.restore(CGF);
  }

public:
  OMPLoopScope(CodeGenFunction &CGF, const OMPLoopDirective &S)
      : CodeGenFunction::RunCleanupsScope(CGF) {
    emitPreInitStmt(CGF, S);
  }
};

class OMPSimdLexicalScope : public CodeGenFunction::LexicalScope {
  CodeGenFunction::OMPPrivateScope InlinedShareds;

  static bool isCapturedVar(CodeGenFunction &CGF, const VarDecl *VD) {
    return CGF.LambdaCaptureFields.lookup(VD) ||
           (CGF.CapturedStmtInfo && CGF.CapturedStmtInfo->lookup(VD)) ||
           (CGF.CurCodeDecl && isa<BlockDecl>(CGF.CurCodeDecl) &&
            cast<BlockDecl>(CGF.CurCodeDecl)->capturesVariable(VD));
  }

public:
  OMPSimdLexicalScope(CodeGenFunction &CGF, const OMPExecutableDirective &S)
      : CodeGenFunction::LexicalScope(CGF, S.getSourceRange()),
        InlinedShareds(CGF) {
    for (const auto *C : S.clauses()) {
      if (const auto *CPI = OMPClauseWithPreInit::get(C)) {
        if (const auto *PreInit =
                cast_or_null<DeclStmt>(CPI->getPreInitStmt())) {
          for (const auto *I : PreInit->decls()) {
            if (!I->hasAttr<OMPCaptureNoInitAttr>()) {
              CGF.EmitVarDecl(cast<VarDecl>(*I));
            } else {
              CodeGenFunction::AutoVarEmission Emission =
                  CGF.EmitAutoVarAlloca(cast<VarDecl>(*I));
              CGF.EmitAutoVarCleanups(Emission);
            }
          }
        }
      } else if (const auto *UDP = dyn_cast<OMPUseDevicePtrClause>(C)) {
        for (const Expr *E : UDP->varlists()) {
          const Decl *D = cast<DeclRefExpr>(E)->getDecl();
          if (const auto *OED = dyn_cast<OMPCapturedExprDecl>(D))
            CGF.EmitVarDecl(*OED);
        }
      }
    }
    if (!isOpenMPSimdDirective(S.getDirectiveKind()))
      CGF.EmitOMPPrivateClause(S, InlinedShareds);
    if (const auto *TG = dyn_cast<OMPTaskgroupDirective>(&S)) {
      if (const Expr *E = TG->getReductionRef())
        CGF.EmitVarDecl(*cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl()));
    }
    const auto *CS = cast_or_null<CapturedStmt>(S.getAssociatedStmt());
    while (CS) {
      for (auto &C : CS->captures()) {
        if (C.capturesVariable() || C.capturesVariableByCopy()) {
          auto *VD = C.getCapturedVar();
          assert(VD == VD->getCanonicalDecl() &&
                 "Canonical decl must be captured.");
          DeclRefExpr DRE(CGF.getContext(), const_cast<VarDecl *>(VD),
                          isCapturedVar(CGF, VD) ||
                              (CGF.CapturedStmtInfo &&
                               InlinedShareds.isGlobalVarCaptured(VD)),
                          VD->getType().getNonReferenceType(), VK_LValue,
                          C.getLocation());
          InlinedShareds.addPrivate(VD, [&CGF, &DRE]() -> Address {
            return CGF.EmitLValue(&DRE).getAddress(CGF);
          });
        }
      }
      CS = dyn_cast<CapturedStmt>(CS->getCapturedStmt());
    }
    (void)InlinedShareds.Privatize();
  }
};

} // namespace

static void emitCommonOMPTargetDirective(CodeGenFunction &CGF,
                                         const OMPExecutableDirective &S,
                                         const RegionCodeGenTy &CodeGen);

LValue CodeGenFunction::EmitOMPSharedLValue(const Expr *E) {
  if (const auto *OrigDRE = dyn_cast<DeclRefExpr>(E)) {
    if (const auto *OrigVD = dyn_cast<VarDecl>(OrigDRE->getDecl())) {
      OrigVD = OrigVD->getCanonicalDecl();
      bool IsCaptured =
          LambdaCaptureFields.lookup(OrigVD) ||
          (CapturedStmtInfo && CapturedStmtInfo->lookup(OrigVD)) ||
          (CurCodeDecl && isa<BlockDecl>(CurCodeDecl));
      DeclRefExpr DRE(getContext(), const_cast<VarDecl *>(OrigVD), IsCaptured,
                      OrigDRE->getType(), VK_LValue, OrigDRE->getExprLoc());
      return EmitLValue(&DRE);
    }
  }
  return EmitLValue(E);
}

llvm::Value *CodeGenFunction::getTypeSize(QualType Ty) {
  ASTContext &C = getContext();
  llvm::Value *Size = nullptr;
  auto SizeInChars = C.getTypeSizeInChars(Ty);
  if (SizeInChars.isZero()) {
    // getTypeSizeInChars() returns 0 for a VLA.
    while (const VariableArrayType *VAT = C.getAsVariableArrayType(Ty)) {
      VlaSizePair VlaSize = getVLASize(VAT);
      Ty = VlaSize.Type;
      Size = Size ? Builder.CreateNUWMul(Size, VlaSize.NumElts)
                  : VlaSize.NumElts;
    }
    SizeInChars = C.getTypeSizeInChars(Ty);
    if (SizeInChars.isZero())
      return llvm::ConstantInt::get(SizeTy, /*V=*/0);
    return Builder.CreateNUWMul(Size, CGM.getSize(SizeInChars));
  }
  return CGM.getSize(SizeInChars);
}

void CodeGenFunction::GenerateOpenMPCapturedVars(
    const CapturedStmt &S, SmallVectorImpl<llvm::Value *> &CapturedVars) {
  const RecordDecl *RD = S.getCapturedRecordDecl();
  auto CurField = RD->field_begin();
  auto CurCap = S.captures().begin();
  for (CapturedStmt::const_capture_init_iterator I = S.capture_init_begin(),
                                                 E = S.capture_init_end();
       I != E; ++I, ++CurField, ++CurCap) {
    if (CurField->hasCapturedVLAType()) {
      const VariableArrayType *VAT = CurField->getCapturedVLAType();
      llvm::Value *Val = VLASizeMap[VAT->getSizeExpr()];
      CapturedVars.push_back(Val);
    } else if (CurCap->capturesThis()) {
      CapturedVars.push_back(CXXThisValue);
    } else if (CurCap->capturesVariableByCopy()) {
      llvm::Value *CV = EmitLoadOfScalar(EmitLValue(*I), CurCap->getLocation());

      // If the field is not a pointer, we need to save the actual value
      // and load it as a void pointer.
      if (!CurField->getType()->isAnyPointerType()) {
        ASTContext &Ctx = getContext();
        Address DstAddr = CreateMemTemp(
            Ctx.getUIntPtrType(),
            Twine(CurCap->getCapturedVar()->getName(), ".casted"));
        LValue DstLV = MakeAddrLValue(DstAddr, Ctx.getUIntPtrType());

        llvm::Value *SrcAddrVal = EmitScalarConversion(
            DstAddr.getPointer(), Ctx.getPointerType(Ctx.getUIntPtrType()),
            Ctx.getPointerType(CurField->getType()), CurCap->getLocation());
        LValue SrcLV =
            MakeNaturalAlignAddrLValue(SrcAddrVal, CurField->getType());

        // Store the value using the source type pointer.
        EmitStoreThroughLValue(RValue::get(CV), SrcLV);

        // Load the value using the destination type pointer.
        CV = EmitLoadOfScalar(DstLV, CurCap->getLocation());
      }
      CapturedVars.push_back(CV);
    } else {
      assert(CurCap->capturesVariable() && "Expected capture by reference.");
      CapturedVars.push_back(EmitLValue(*I).getAddress(*this).getPointer());
    }
  }
}

static Address castValueFromUintptr(CodeGenFunction &CGF, SourceLocation Loc,
                                    QualType DstType, StringRef Name,
                                    LValue AddrLV) {
  ASTContext &Ctx = CGF.getContext();

  llvm::Value *CastedPtr = CGF.EmitScalarConversion(
      AddrLV.getAddress(CGF).getPointer(), Ctx.getUIntPtrType(),
      Ctx.getPointerType(DstType), Loc);
  Address TmpAddr =
      CGF.MakeNaturalAlignAddrLValue(CastedPtr, Ctx.getPointerType(DstType))
          .getAddress(CGF);
  return TmpAddr;
}

static QualType getCanonicalParamType(ASTContext &C, QualType T) {
  if (T->isLValueReferenceType())
    return C.getLValueReferenceType(
        getCanonicalParamType(C, T.getNonReferenceType()),
        /*SpelledAsLValue=*/false);
  if (T->isPointerType())
    return C.getPointerType(getCanonicalParamType(C, T->getPointeeType()));
  if (const ArrayType *A = T->getAsArrayTypeUnsafe()) {
    if (const auto *VLA = dyn_cast<VariableArrayType>(A))
      return getCanonicalParamType(C, VLA->getElementType());
    if (!A->isVariablyModifiedType())
      return C.getCanonicalType(T);
  }
  return C.getCanonicalParamType(T);
}

namespace {
  /// Contains required data for proper outlined function codegen.
  struct FunctionOptions {
    /// Captured statement for which the function is generated.
    const CapturedStmt *S = nullptr;
    /// true if cast to/from  UIntPtr is required for variables captured by
    /// value.
    const bool UIntPtrCastRequired = true;
    /// true if only casted arguments must be registered as local args or VLA
    /// sizes.
    const bool RegisterCastedArgsOnly = false;
    /// Name of the generated function.
    const StringRef FunctionName;
    explicit FunctionOptions(const CapturedStmt *S, bool UIntPtrCastRequired,
                             bool RegisterCastedArgsOnly,
                             StringRef FunctionName)
        : S(S), UIntPtrCastRequired(UIntPtrCastRequired),
          RegisterCastedArgsOnly(UIntPtrCastRequired && RegisterCastedArgsOnly),
          FunctionName(FunctionName) {}
  };
}

static llvm::Function *emitOutlinedFunctionPrologue(
    CodeGenFunction &CGF, FunctionArgList &Args,
    llvm::MapVector<const Decl *, std::pair<const VarDecl *, Address>>
        &LocalAddrs,
    llvm::DenseMap<const Decl *, std::pair<const Expr *, llvm::Value *>>
        &VLASizes,
    llvm::Value *&CXXThisValue, const FunctionOptions &FO) {
  const CapturedDecl *CD = FO.S->getCapturedDecl();
  const RecordDecl *RD = FO.S->getCapturedRecordDecl();
  assert(CD->hasBody() && "missing CapturedDecl body");

  CXXThisValue = nullptr;
  // Build the argument list.
  CodeGenModule &CGM = CGF.CGM;
  ASTContext &Ctx = CGM.getContext();
  FunctionArgList TargetArgs;
  Args.append(CD->param_begin(),
              std::next(CD->param_begin(), CD->getContextParamPosition()));
  TargetArgs.append(
      CD->param_begin(),
      std::next(CD->param_begin(), CD->getContextParamPosition()));
  auto I = FO.S->captures().begin();
  FunctionDecl *DebugFunctionDecl = nullptr;
  if (!FO.UIntPtrCastRequired) {
    FunctionProtoType::ExtProtoInfo EPI;
    QualType FunctionTy = Ctx.getFunctionType(Ctx.VoidTy, llvm::None, EPI);
    DebugFunctionDecl = FunctionDecl::Create(
        Ctx, Ctx.getTranslationUnitDecl(), FO.S->getBeginLoc(),
        SourceLocation(), DeclarationName(), FunctionTy,
        Ctx.getTrivialTypeSourceInfo(FunctionTy), SC_Static,
        /*isInlineSpecified=*/false, /*hasWrittenPrototype=*/false);
  }
  for (const FieldDecl *FD : RD->fields()) {
    QualType ArgType = FD->getType();
    IdentifierInfo *II = nullptr;
    VarDecl *CapVar = nullptr;

    // If this is a capture by copy and the type is not a pointer, the outlined
    // function argument type should be uintptr and the value properly casted to
    // uintptr. This is necessary given that the runtime library is only able to
    // deal with pointers. We can pass in the same way the VLA type sizes to the
    // outlined function.
    if (FO.UIntPtrCastRequired &&
        ((I->capturesVariableByCopy() && !ArgType->isAnyPointerType()) ||
         I->capturesVariableArrayType()))
      ArgType = Ctx.getUIntPtrType();

    if (I->capturesVariable() || I->capturesVariableByCopy()) {
      CapVar = I->getCapturedVar();
      II = CapVar->getIdentifier();
    } else if (I->capturesThis()) {
      II = &Ctx.Idents.get("this");
    } else {
      assert(I->capturesVariableArrayType());
      II = &Ctx.Idents.get("vla");
    }
    if (ArgType->isVariablyModifiedType())
      ArgType = getCanonicalParamType(Ctx, ArgType);
    VarDecl *Arg;
    if (DebugFunctionDecl && (CapVar || I->capturesThis())) {
      Arg = ParmVarDecl::Create(
          Ctx, DebugFunctionDecl,
          CapVar ? CapVar->getBeginLoc() : FD->getBeginLoc(),
          CapVar ? CapVar->getLocation() : FD->getLocation(), II, ArgType,
          /*TInfo=*/nullptr, SC_None, /*DefArg=*/nullptr);
    } else {
      Arg = ImplicitParamDecl::Create(Ctx, /*DC=*/nullptr, FD->getLocation(),
                                      II, ArgType, ImplicitParamDecl::Other);
    }
    Args.emplace_back(Arg);
    // Do not cast arguments if we emit function with non-original types.
    TargetArgs.emplace_back(
        FO.UIntPtrCastRequired
            ? Arg
            : CGM.getOpenMPRuntime().translateParameter(FD, Arg));
    ++I;
  }
  Args.append(
      std::next(CD->param_begin(), CD->getContextParamPosition() + 1),
      CD->param_end());
  TargetArgs.append(
      std::next(CD->param_begin(), CD->getContextParamPosition() + 1),
      CD->param_end());

  // Create the function declaration.
  const CGFunctionInfo &FuncInfo =
      CGM.getTypes().arrangeBuiltinFunctionDeclaration(Ctx.VoidTy, TargetArgs);
  llvm::FunctionType *FuncLLVMTy = CGM.getTypes().GetFunctionType(FuncInfo);

  auto *F =
      llvm::Function::Create(FuncLLVMTy, llvm::GlobalValue::InternalLinkage,
                             FO.FunctionName, &CGM.getModule());
  CGM.SetInternalFunctionAttributes(CD, F, FuncInfo);
  if (CD->isNothrow())
    F->setDoesNotThrow();
  F->setDoesNotRecurse();

  // Generate the function.
  CGF.StartFunction(CD, Ctx.VoidTy, F, FuncInfo, TargetArgs,
                    FO.S->getBeginLoc(), CD->getBody()->getBeginLoc());
  unsigned Cnt = CD->getContextParamPosition();
  I = FO.S->captures().begin();
  for (const FieldDecl *FD : RD->fields()) {
    // Do not map arguments if we emit function with non-original types.
    Address LocalAddr(Address::invalid());
    if (!FO.UIntPtrCastRequired && Args[Cnt] != TargetArgs[Cnt]) {
      LocalAddr = CGM.getOpenMPRuntime().getParameterAddress(CGF, Args[Cnt],
                                                             TargetArgs[Cnt]);
    } else {
      LocalAddr = CGF.GetAddrOfLocalVar(Args[Cnt]);
    }
    // If we are capturing a pointer by copy we don't need to do anything, just
    // use the value that we get from the arguments.
    if (I->capturesVariableByCopy() && FD->getType()->isAnyPointerType()) {
      const VarDecl *CurVD = I->getCapturedVar();
      if (!FO.RegisterCastedArgsOnly)
        LocalAddrs.insert({Args[Cnt], {CurVD, LocalAddr}});
      ++Cnt;
      ++I;
      continue;
    }

    LValue ArgLVal = CGF.MakeAddrLValue(LocalAddr, Args[Cnt]->getType(),
                                        AlignmentSource::Decl);
    if (FD->hasCapturedVLAType()) {
      if (FO.UIntPtrCastRequired) {
        ArgLVal = CGF.MakeAddrLValue(
            castValueFromUintptr(CGF, I->getLocation(), FD->getType(),
                                 Args[Cnt]->getName(), ArgLVal),
            FD->getType(), AlignmentSource::Decl);
      }
      llvm::Value *ExprArg = CGF.EmitLoadOfScalar(ArgLVal, I->getLocation());
      const VariableArrayType *VAT = FD->getCapturedVLAType();
      VLASizes.try_emplace(Args[Cnt], VAT->getSizeExpr(), ExprArg);
    } else if (I->capturesVariable()) {
      const VarDecl *Var = I->getCapturedVar();
      QualType VarTy = Var->getType();
      Address ArgAddr = ArgLVal.getAddress(CGF);
      if (ArgLVal.getType()->isLValueReferenceType()) {
        ArgAddr = CGF.EmitLoadOfReference(ArgLVal);
      } else if (!VarTy->isVariablyModifiedType() || !VarTy->isPointerType()) {
        assert(ArgLVal.getType()->isPointerType());
        ArgAddr = CGF.EmitLoadOfPointer(
            ArgAddr, ArgLVal.getType()->castAs<PointerType>());
      }
      if (!FO.RegisterCastedArgsOnly) {
        LocalAddrs.insert(
            {Args[Cnt],
             {Var, Address(ArgAddr.getPointer(), Ctx.getDeclAlign(Var))}});
      }
    } else if (I->capturesVariableByCopy()) {
      assert(!FD->getType()->isAnyPointerType() &&
             "Not expecting a captured pointer.");
      const VarDecl *Var = I->getCapturedVar();
      LocalAddrs.insert({Args[Cnt],
                         {Var, FO.UIntPtrCastRequired
                                   ? castValueFromUintptr(
                                         CGF, I->getLocation(), FD->getType(),
                                         Args[Cnt]->getName(), ArgLVal)
                                   : ArgLVal.getAddress(CGF)}});
    } else {
      // If 'this' is captured, load it into CXXThisValue.
      assert(I->capturesThis());
      CXXThisValue = CGF.EmitLoadOfScalar(ArgLVal, I->getLocation());
      LocalAddrs.insert({Args[Cnt], {nullptr, ArgLVal.getAddress(CGF)}});
    }
    ++Cnt;
    ++I;
  }

  return F;
}

llvm::Function *
CodeGenFunction::GenerateOpenMPCapturedStmtFunction(const CapturedStmt &S) {
  assert(
      CapturedStmtInfo &&
      "CapturedStmtInfo should be set when generating the captured function");
  const CapturedDecl *CD = S.getCapturedDecl();
  // Build the argument list.
  bool NeedWrapperFunction =
      getDebugInfo() &&
      CGM.getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo;
  FunctionArgList Args;
  llvm::MapVector<const Decl *, std::pair<const VarDecl *, Address>> LocalAddrs;
  llvm::DenseMap<const Decl *, std::pair<const Expr *, llvm::Value *>> VLASizes;
  SmallString<256> Buffer;
  llvm::raw_svector_ostream Out(Buffer);
  Out << CapturedStmtInfo->getHelperName();
  if (NeedWrapperFunction)
    Out << "_debug__";
  FunctionOptions FO(&S, !NeedWrapperFunction, /*RegisterCastedArgsOnly=*/false,
                     Out.str());
  llvm::Function *F = emitOutlinedFunctionPrologue(*this, Args, LocalAddrs,
                                                   VLASizes, CXXThisValue, FO);
  CodeGenFunction::OMPPrivateScope LocalScope(*this);
  for (const auto &LocalAddrPair : LocalAddrs) {
    if (LocalAddrPair.second.first) {
      LocalScope.addPrivate(LocalAddrPair.second.first, [&LocalAddrPair]() {
        return LocalAddrPair.second.second;
      });
    }
  }
  (void)LocalScope.Privatize();
  for (const auto &VLASizePair : VLASizes)
    VLASizeMap[VLASizePair.second.first] = VLASizePair.second.second;
  PGO.assignRegionCounters(GlobalDecl(CD), F);
  CapturedStmtInfo->EmitBody(*this, CD->getBody());
  (void)LocalScope.ForceCleanup();
  FinishFunction(CD->getBodyRBrace());
  if (!NeedWrapperFunction)
    return F;

  FunctionOptions WrapperFO(&S, /*UIntPtrCastRequired=*/true,
                            /*RegisterCastedArgsOnly=*/true,
                            CapturedStmtInfo->getHelperName());
  CodeGenFunction WrapperCGF(CGM, /*suppressNewContext=*/true);
  WrapperCGF.CapturedStmtInfo = CapturedStmtInfo;
  Args.clear();
  LocalAddrs.clear();
  VLASizes.clear();
  llvm::Function *WrapperF =
      emitOutlinedFunctionPrologue(WrapperCGF, Args, LocalAddrs, VLASizes,
                                   WrapperCGF.CXXThisValue, WrapperFO);
  llvm::SmallVector<llvm::Value *, 4> CallArgs;
  for (const auto *Arg : Args) {
    llvm::Value *CallArg;
    auto I = LocalAddrs.find(Arg);
    if (I != LocalAddrs.end()) {
      LValue LV = WrapperCGF.MakeAddrLValue(
          I->second.second,
          I->second.first ? I->second.first->getType() : Arg->getType(),
          AlignmentSource::Decl);
      CallArg = WrapperCGF.EmitLoadOfScalar(LV, S.getBeginLoc());
    } else {
      auto EI = VLASizes.find(Arg);
      if (EI != VLASizes.end()) {
        CallArg = EI->second.second;
      } else {
        LValue LV = WrapperCGF.MakeAddrLValue(WrapperCGF.GetAddrOfLocalVar(Arg),
                                              Arg->getType(),
                                              AlignmentSource::Decl);
        CallArg = WrapperCGF.EmitLoadOfScalar(LV, S.getBeginLoc());
      }
    }
    CallArgs.emplace_back(WrapperCGF.EmitFromMemory(CallArg, Arg->getType()));
  }
  CGM.getOpenMPRuntime().emitOutlinedFunctionCall(WrapperCGF, S.getBeginLoc(),
                                                  F, CallArgs);
  WrapperCGF.FinishFunction();
  return WrapperF;
}

//===----------------------------------------------------------------------===//
//                              OpenMP Directive Emission
//===----------------------------------------------------------------------===//
void CodeGenFunction::EmitOMPAggregateAssign(
    Address DestAddr, Address SrcAddr, QualType OriginalType,
    const llvm::function_ref<void(Address, Address)> CopyGen) {
  // Perform element-by-element initialization.
  QualType ElementTy;

  // Drill down to the base element type on both arrays.
  const ArrayType *ArrayTy = OriginalType->getAsArrayTypeUnsafe();
  llvm::Value *NumElements = emitArrayLength(ArrayTy, ElementTy, DestAddr);
  SrcAddr = Builder.CreateElementBitCast(SrcAddr, DestAddr.getElementType());

  llvm::Value *SrcBegin = SrcAddr.getPointer();
  llvm::Value *DestBegin = DestAddr.getPointer();
  // Cast from pointer to array type to pointer to single element.
  llvm::Value *DestEnd = Builder.CreateGEP(DestBegin, NumElements);
  // The basic structure here is a while-do loop.
  llvm::BasicBlock *BodyBB = createBasicBlock("omp.arraycpy.body");
  llvm::BasicBlock *DoneBB = createBasicBlock("omp.arraycpy.done");
  llvm::Value *IsEmpty =
      Builder.CreateICmpEQ(DestBegin, DestEnd, "omp.arraycpy.isempty");
  Builder.CreateCondBr(IsEmpty, DoneBB, BodyBB);

  // Enter the loop body, making that address the current address.
  llvm::BasicBlock *EntryBB = Builder.GetInsertBlock();
  EmitBlock(BodyBB);

  CharUnits ElementSize = getContext().getTypeSizeInChars(ElementTy);

  llvm::PHINode *SrcElementPHI =
    Builder.CreatePHI(SrcBegin->getType(), 2, "omp.arraycpy.srcElementPast");
  SrcElementPHI->addIncoming(SrcBegin, EntryBB);
  Address SrcElementCurrent =
      Address(SrcElementPHI,
              SrcAddr.getAlignment().alignmentOfArrayElement(ElementSize));

  llvm::PHINode *DestElementPHI =
    Builder.CreatePHI(DestBegin->getType(), 2, "omp.arraycpy.destElementPast");
  DestElementPHI->addIncoming(DestBegin, EntryBB);
  Address DestElementCurrent =
    Address(DestElementPHI,
            DestAddr.getAlignment().alignmentOfArrayElement(ElementSize));

  // Emit copy.
  CopyGen(DestElementCurrent, SrcElementCurrent);

  // Shift the address forward by one element.
  llvm::Value *DestElementNext = Builder.CreateConstGEP1_32(
      DestElementPHI, /*Idx0=*/1, "omp.arraycpy.dest.element");
  llvm::Value *SrcElementNext = Builder.CreateConstGEP1_32(
      SrcElementPHI, /*Idx0=*/1, "omp.arraycpy.src.element");
  // Check whether we've reached the end.
  llvm::Value *Done =
      Builder.CreateICmpEQ(DestElementNext, DestEnd, "omp.arraycpy.done");
  Builder.CreateCondBr(Done, DoneBB, BodyBB);
  DestElementPHI->addIncoming(DestElementNext, Builder.GetInsertBlock());
  SrcElementPHI->addIncoming(SrcElementNext, Builder.GetInsertBlock());

  // Done.
  EmitBlock(DoneBB, /*IsFinished=*/true);
}

void CodeGenFunction::EmitOMPCopy(QualType OriginalType, Address DestAddr,
                                  Address SrcAddr, const VarDecl *DestVD,
                                  const VarDecl *SrcVD, const Expr *Copy) {
  if (OriginalType->isArrayType()) {
    const auto *BO = dyn_cast<BinaryOperator>(Copy);
    if (BO && BO->getOpcode() == BO_Assign) {
      // Perform simple memcpy for simple copying.
      LValue Dest = MakeAddrLValue(DestAddr, OriginalType);
      LValue Src = MakeAddrLValue(SrcAddr, OriginalType);
      EmitAggregateAssign(Dest, Src, OriginalType);
    } else {
      // For arrays with complex element types perform element by element
      // copying.
      EmitOMPAggregateAssign(
          DestAddr, SrcAddr, OriginalType,
          [this, Copy, SrcVD, DestVD](Address DestElement, Address SrcElement) {
            // Working with the single array element, so have to remap
            // destination and source variables to corresponding array
            // elements.
            CodeGenFunction::OMPPrivateScope Remap(*this);
            Remap.addPrivate(DestVD, [DestElement]() { return DestElement; });
            Remap.addPrivate(SrcVD, [SrcElement]() { return SrcElement; });
            (void)Remap.Privatize();
            EmitIgnoredExpr(Copy);
          });
    }
  } else {
    // Remap pseudo source variable to private copy.
    CodeGenFunction::OMPPrivateScope Remap(*this);
    Remap.addPrivate(SrcVD, [SrcAddr]() { return SrcAddr; });
    Remap.addPrivate(DestVD, [DestAddr]() { return DestAddr; });
    (void)Remap.Privatize();
    // Emit copying of the whole variable.
    EmitIgnoredExpr(Copy);
  }
}

bool CodeGenFunction::EmitOMPFirstprivateClause(const OMPExecutableDirective &D,
                                                OMPPrivateScope &PrivateScope) {
  if (!HaveInsertPoint())
    return false;
  bool DeviceConstTarget =
      getLangOpts().OpenMPIsDevice &&
      isOpenMPTargetExecutionDirective(D.getDirectiveKind());
  bool FirstprivateIsLastprivate = false;
  llvm::DenseSet<const VarDecl *> Lastprivates;
  for (const auto *C : D.getClausesOfKind<OMPLastprivateClause>()) {
    for (const auto *D : C->varlists())
      Lastprivates.insert(
          cast<VarDecl>(cast<DeclRefExpr>(D)->getDecl())->getCanonicalDecl());
  }
  llvm::DenseSet<const VarDecl *> EmittedAsFirstprivate;
  llvm::SmallVector<OpenMPDirectiveKind, 4> CaptureRegions;
  getOpenMPCaptureRegions(CaptureRegions, D.getDirectiveKind());
  // Force emission of the firstprivate copy if the directive does not emit
  // outlined function, like omp for, omp simd, omp distribute etc.
  bool MustEmitFirstprivateCopy =
      CaptureRegions.size() == 1 && CaptureRegions.back() == OMPD_unknown;
  for (const auto *C : D.getClausesOfKind<OMPFirstprivateClause>()) {
    auto IRef = C->varlist_begin();
    auto InitsRef = C->inits().begin();
    for (const Expr *IInit : C->private_copies()) {
      const auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
      bool ThisFirstprivateIsLastprivate =
          Lastprivates.count(OrigVD->getCanonicalDecl()) > 0;
      const FieldDecl *FD = CapturedStmtInfo->lookup(OrigVD);
      const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(IInit)->getDecl());
      if (!MustEmitFirstprivateCopy && !ThisFirstprivateIsLastprivate && FD &&
          !FD->getType()->isReferenceType() &&
          (!VD || !VD->hasAttr<OMPAllocateDeclAttr>())) {
        EmittedAsFirstprivate.insert(OrigVD->getCanonicalDecl());
        ++IRef;
        ++InitsRef;
        continue;
      }
      // Do not emit copy for firstprivate constant variables in target regions,
      // captured by reference.
      if (DeviceConstTarget && OrigVD->getType().isConstant(getContext()) &&
          FD && FD->getType()->isReferenceType() &&
          (!VD || !VD->hasAttr<OMPAllocateDeclAttr>())) {
        (void)CGM.getOpenMPRuntime().registerTargetFirstprivateCopy(*this,
                                                                    OrigVD);
        ++IRef;
        ++InitsRef;
        continue;
      }
      FirstprivateIsLastprivate =
          FirstprivateIsLastprivate || ThisFirstprivateIsLastprivate;
      if (EmittedAsFirstprivate.insert(OrigVD->getCanonicalDecl()).second) {
        const auto *VDInit =
            cast<VarDecl>(cast<DeclRefExpr>(*InitsRef)->getDecl());
        bool IsRegistered;
        DeclRefExpr DRE(getContext(), const_cast<VarDecl *>(OrigVD),
                        /*RefersToEnclosingVariableOrCapture=*/FD != nullptr,
                        (*IRef)->getType(), VK_LValue, (*IRef)->getExprLoc());
        LValue OriginalLVal;
        if (!FD) {
          // Check if the firstprivate variable is just a constant value.
          ConstantEmission CE = tryEmitAsConstant(&DRE);
          if (CE && !CE.isReference()) {
            // Constant value, no need to create a copy.
            ++IRef;
            ++InitsRef;
            continue;
          }
          if (CE && CE.isReference()) {
            OriginalLVal = CE.getReferenceLValue(*this, &DRE);
          } else {
            assert(!CE && "Expected non-constant firstprivate.");
            OriginalLVal = EmitLValue(&DRE);
          }
        } else {
          OriginalLVal = EmitLValue(&DRE);
        }
        QualType Type = VD->getType();
        if (Type->isArrayType()) {
          // Emit VarDecl with copy init for arrays.
          // Get the address of the original variable captured in current
          // captured region.
          IsRegistered = PrivateScope.addPrivate(
              OrigVD, [this, VD, Type, OriginalLVal, VDInit]() {
                AutoVarEmission Emission = EmitAutoVarAlloca(*VD);
                const Expr *Init = VD->getInit();
                if (!isa<CXXConstructExpr>(Init) ||
                    isTrivialInitializer(Init)) {
                  // Perform simple memcpy.
                  LValue Dest =
                      MakeAddrLValue(Emission.getAllocatedAddress(), Type);
                  EmitAggregateAssign(Dest, OriginalLVal, Type);
                } else {
                  EmitOMPAggregateAssign(
                      Emission.getAllocatedAddress(),
                      OriginalLVal.getAddress(*this), Type,
                      [this, VDInit, Init](Address DestElement,
                                           Address SrcElement) {
                        // Clean up any temporaries needed by the
                        // initialization.
                        RunCleanupsScope InitScope(*this);
                        // Emit initialization for single element.
                        setAddrOfLocalVar(VDInit, SrcElement);
                        EmitAnyExprToMem(Init, DestElement,
                                         Init->getType().getQualifiers(),
                                         /*IsInitializer*/ false);
                        LocalDeclMap.erase(VDInit);
                      });
                }
                EmitAutoVarCleanups(Emission);
                return Emission.getAllocatedAddress();
              });
        } else {
          Address OriginalAddr = OriginalLVal.getAddress(*this);
          IsRegistered = PrivateScope.addPrivate(
              OrigVD, [this, VDInit, OriginalAddr, VD]() {
                // Emit private VarDecl with copy init.
                // Remap temp VDInit variable to the address of the original
                // variable (for proper handling of captured global variables).
                setAddrOfLocalVar(VDInit, OriginalAddr);
                EmitDecl(*VD);
                LocalDeclMap.erase(VDInit);
                return GetAddrOfLocalVar(VD);
              });
        }
        assert(IsRegistered &&
               "firstprivate var already registered as private");
        // Silence the warning about unused variable.
        (void)IsRegistered;
      }
      ++IRef;
      ++InitsRef;
    }
  }
  return FirstprivateIsLastprivate && !EmittedAsFirstprivate.empty();
}

void CodeGenFunction::EmitOMPPrivateClause(
    const OMPExecutableDirective &D,
    CodeGenFunction::OMPPrivateScope &PrivateScope) {
  if (!HaveInsertPoint())
    return;
  llvm::DenseSet<const VarDecl *> EmittedAsPrivate;
  for (const auto *C : D.getClausesOfKind<OMPPrivateClause>()) {
    auto IRef = C->varlist_begin();
    for (const Expr *IInit : C->private_copies()) {
      const auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
      if (EmittedAsPrivate.insert(OrigVD->getCanonicalDecl()).second) {
        const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(IInit)->getDecl());
        bool IsRegistered = PrivateScope.addPrivate(OrigVD, [this, VD]() {
          // Emit private VarDecl with copy init.
          EmitDecl(*VD);
          return GetAddrOfLocalVar(VD);
        });
        assert(IsRegistered && "private var already registered as private");
        // Silence the warning about unused variable.
        (void)IsRegistered;
      }
      ++IRef;
    }
  }
}

bool CodeGenFunction::EmitOMPCopyinClause(const OMPExecutableDirective &D) {
  if (!HaveInsertPoint())
    return false;
  // threadprivate_var1 = master_threadprivate_var1;
  // operator=(threadprivate_var2, master_threadprivate_var2);
  // ...
  // __kmpc_barrier(&loc, global_tid);
  llvm::DenseSet<const VarDecl *> CopiedVars;
  llvm::BasicBlock *CopyBegin = nullptr, *CopyEnd = nullptr;
  for (const auto *C : D.getClausesOfKind<OMPCopyinClause>()) {
    auto IRef = C->varlist_begin();
    auto ISrcRef = C->source_exprs().begin();
    auto IDestRef = C->destination_exprs().begin();
    for (const Expr *AssignOp : C->assignment_ops()) {
      const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
      QualType Type = VD->getType();
      if (CopiedVars.insert(VD->getCanonicalDecl()).second) {
        // Get the address of the master variable. If we are emitting code with
        // TLS support, the address is passed from the master as field in the
        // captured declaration.
        Address MasterAddr = Address::invalid();
        if (getLangOpts().OpenMPUseTLS &&
            getContext().getTargetInfo().isTLSSupported()) {
          assert(CapturedStmtInfo->lookup(VD) &&
                 "Copyin threadprivates should have been captured!");
          DeclRefExpr DRE(getContext(), const_cast<VarDecl *>(VD), true,
                          (*IRef)->getType(), VK_LValue, (*IRef)->getExprLoc());
          MasterAddr = EmitLValue(&DRE).getAddress(*this);
          LocalDeclMap.erase(VD);
        } else {
          MasterAddr =
            Address(VD->isStaticLocal() ? CGM.getStaticLocalDeclAddress(VD)
                                        : CGM.GetAddrOfGlobal(VD),
                    getContext().getDeclAlign(VD));
        }
        // Get the address of the threadprivate variable.
        Address PrivateAddr = EmitLValue(*IRef).getAddress(*this);
        if (CopiedVars.size() == 1) {
          // At first check if current thread is a master thread. If it is, no
          // need to copy data.
          CopyBegin = createBasicBlock("copyin.not.master");
          CopyEnd = createBasicBlock("copyin.not.master.end");
          Builder.CreateCondBr(
              Builder.CreateICmpNE(
                  Builder.CreatePtrToInt(MasterAddr.getPointer(), CGM.IntPtrTy),
                  Builder.CreatePtrToInt(PrivateAddr.getPointer(),
                                         CGM.IntPtrTy)),
              CopyBegin, CopyEnd);
          EmitBlock(CopyBegin);
        }
        const auto *SrcVD =
            cast<VarDecl>(cast<DeclRefExpr>(*ISrcRef)->getDecl());
        const auto *DestVD =
            cast<VarDecl>(cast<DeclRefExpr>(*IDestRef)->getDecl());
        EmitOMPCopy(Type, PrivateAddr, MasterAddr, DestVD, SrcVD, AssignOp);
      }
      ++IRef;
      ++ISrcRef;
      ++IDestRef;
    }
  }
  if (CopyEnd) {
    // Exit out of copying procedure for non-master thread.
    EmitBlock(CopyEnd, /*IsFinished=*/true);
    return true;
  }
  return false;
}

bool CodeGenFunction::EmitOMPLastprivateClauseInit(
    const OMPExecutableDirective &D, OMPPrivateScope &PrivateScope) {
  if (!HaveInsertPoint())
    return false;
  bool HasAtLeastOneLastprivate = false;
  llvm::DenseSet<const VarDecl *> SIMDLCVs;
  if (isOpenMPSimdDirective(D.getDirectiveKind())) {
    const auto *LoopDirective = cast<OMPLoopDirective>(&D);
    for (const Expr *C : LoopDirective->counters()) {
      SIMDLCVs.insert(
          cast<VarDecl>(cast<DeclRefExpr>(C)->getDecl())->getCanonicalDecl());
    }
  }
  llvm::DenseSet<const VarDecl *> AlreadyEmittedVars;
  for (const auto *C : D.getClausesOfKind<OMPLastprivateClause>()) {
    HasAtLeastOneLastprivate = true;
    if (isOpenMPTaskLoopDirective(D.getDirectiveKind()) &&
        !getLangOpts().OpenMPSimd)
      break;
    auto IRef = C->varlist_begin();
    auto IDestRef = C->destination_exprs().begin();
    for (const Expr *IInit : C->private_copies()) {
      // Keep the address of the original variable for future update at the end
      // of the loop.
      const auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
      // Taskloops do not require additional initialization, it is done in
      // runtime support library.
      if (AlreadyEmittedVars.insert(OrigVD->getCanonicalDecl()).second) {
        const auto *DestVD =
            cast<VarDecl>(cast<DeclRefExpr>(*IDestRef)->getDecl());
        PrivateScope.addPrivate(DestVD, [this, OrigVD, IRef]() {
          DeclRefExpr DRE(getContext(), const_cast<VarDecl *>(OrigVD),
                          /*RefersToEnclosingVariableOrCapture=*/
                              CapturedStmtInfo->lookup(OrigVD) != nullptr,
                          (*IRef)->getType(), VK_LValue, (*IRef)->getExprLoc());
          return EmitLValue(&DRE).getAddress(*this);
        });
        // Check if the variable is also a firstprivate: in this case IInit is
        // not generated. Initialization of this variable will happen in codegen
        // for 'firstprivate' clause.
        if (IInit && !SIMDLCVs.count(OrigVD->getCanonicalDecl())) {
          const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(IInit)->getDecl());
          bool IsRegistered = PrivateScope.addPrivate(OrigVD, [this, VD]() {
            // Emit private VarDecl with copy init.
            EmitDecl(*VD);
            return GetAddrOfLocalVar(VD);
          });
          assert(IsRegistered &&
                 "lastprivate var already registered as private");
          (void)IsRegistered;
        }
      }
      ++IRef;
      ++IDestRef;
    }
  }
  return HasAtLeastOneLastprivate;
}

void CodeGenFunction::EmitOMPLastprivateClauseFinal(
    const OMPExecutableDirective &D, bool NoFinals,
    llvm::Value *IsLastIterCond) {
  if (!HaveInsertPoint())
    return;
  // Emit following code:
  // if (<IsLastIterCond>) {
  //   orig_var1 = private_orig_var1;
  //   ...
  //   orig_varn = private_orig_varn;
  // }
  llvm::BasicBlock *ThenBB = nullptr;
  llvm::BasicBlock *DoneBB = nullptr;
  if (IsLastIterCond) {
    ThenBB = createBasicBlock(".omp.lastprivate.then");
    DoneBB = createBasicBlock(".omp.lastprivate.done");
    Builder.CreateCondBr(IsLastIterCond, ThenBB, DoneBB);
    EmitBlock(ThenBB);
  }
  llvm::DenseSet<const VarDecl *> AlreadyEmittedVars;
  llvm::DenseMap<const VarDecl *, const Expr *> LoopCountersAndUpdates;
  if (const auto *LoopDirective = dyn_cast<OMPLoopDirective>(&D)) {
    auto IC = LoopDirective->counters().begin();
    for (const Expr *F : LoopDirective->finals()) {
      const auto *D =
          cast<VarDecl>(cast<DeclRefExpr>(*IC)->getDecl())->getCanonicalDecl();
      if (NoFinals)
        AlreadyEmittedVars.insert(D);
      else
        LoopCountersAndUpdates[D] = F;
      ++IC;
    }
  }
  for (const auto *C : D.getClausesOfKind<OMPLastprivateClause>()) {
    auto IRef = C->varlist_begin();
    auto ISrcRef = C->source_exprs().begin();
    auto IDestRef = C->destination_exprs().begin();
    for (const Expr *AssignOp : C->assignment_ops()) {
      const auto *PrivateVD =
          cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
      QualType Type = PrivateVD->getType();
      const auto *CanonicalVD = PrivateVD->getCanonicalDecl();
      if (AlreadyEmittedVars.insert(CanonicalVD).second) {
        // If lastprivate variable is a loop control variable for loop-based
        // directive, update its value before copyin back to original
        // variable.
        if (const Expr *FinalExpr = LoopCountersAndUpdates.lookup(CanonicalVD))
          EmitIgnoredExpr(FinalExpr);
        const auto *SrcVD =
            cast<VarDecl>(cast<DeclRefExpr>(*ISrcRef)->getDecl());
        const auto *DestVD =
            cast<VarDecl>(cast<DeclRefExpr>(*IDestRef)->getDecl());
        // Get the address of the original variable.
        Address OriginalAddr = GetAddrOfLocalVar(DestVD);
        // Get the address of the private variable.
        Address PrivateAddr = GetAddrOfLocalVar(PrivateVD);
        if (const auto *RefTy = PrivateVD->getType()->getAs<ReferenceType>())
          PrivateAddr =
              Address(Builder.CreateLoad(PrivateAddr),
                      getNaturalTypeAlignment(RefTy->getPointeeType()));
        EmitOMPCopy(Type, OriginalAddr, PrivateAddr, DestVD, SrcVD, AssignOp);
      }
      ++IRef;
      ++ISrcRef;
      ++IDestRef;
    }
    if (const Expr *PostUpdate = C->getPostUpdateExpr())
      EmitIgnoredExpr(PostUpdate);
  }
  if (IsLastIterCond)
    EmitBlock(DoneBB, /*IsFinished=*/true);
}

void CodeGenFunction::EmitOMPReductionClauseInit(
    const OMPExecutableDirective &D,
    CodeGenFunction::OMPPrivateScope &PrivateScope) {
  if (!HaveInsertPoint())
    return;
  SmallVector<const Expr *, 4> Shareds;
  SmallVector<const Expr *, 4> Privates;
  SmallVector<const Expr *, 4> ReductionOps;
  SmallVector<const Expr *, 4> LHSs;
  SmallVector<const Expr *, 4> RHSs;
  for (const auto *C : D.getClausesOfKind<OMPReductionClause>()) {
    auto IPriv = C->privates().begin();
    auto IRed = C->reduction_ops().begin();
    auto ILHS = C->lhs_exprs().begin();
    auto IRHS = C->rhs_exprs().begin();
    for (const Expr *Ref : C->varlists()) {
      Shareds.emplace_back(Ref);
      Privates.emplace_back(*IPriv);
      ReductionOps.emplace_back(*IRed);
      LHSs.emplace_back(*ILHS);
      RHSs.emplace_back(*IRHS);
      std::advance(IPriv, 1);
      std::advance(IRed, 1);
      std::advance(ILHS, 1);
      std::advance(IRHS, 1);
    }
  }
  ReductionCodeGen RedCG(Shareds, Privates, ReductionOps);
  unsigned Count = 0;
  auto ILHS = LHSs.begin();
  auto IRHS = RHSs.begin();
  auto IPriv = Privates.begin();
  for (const Expr *IRef : Shareds) {
    const auto *PrivateVD = cast<VarDecl>(cast<DeclRefExpr>(*IPriv)->getDecl());
    // Emit private VarDecl with reduction init.
    RedCG.emitSharedLValue(*this, Count);
    RedCG.emitAggregateType(*this, Count);
    AutoVarEmission Emission = EmitAutoVarAlloca(*PrivateVD);
    RedCG.emitInitialization(*this, Count, Emission.getAllocatedAddress(),
                             RedCG.getSharedLValue(Count),
                             [&Emission](CodeGenFunction &CGF) {
                               CGF.EmitAutoVarInit(Emission);
                               return true;
                             });
    EmitAutoVarCleanups(Emission);
    Address BaseAddr = RedCG.adjustPrivateAddress(
        *this, Count, Emission.getAllocatedAddress());
    bool IsRegistered = PrivateScope.addPrivate(
        RedCG.getBaseDecl(Count), [BaseAddr]() { return BaseAddr; });
    assert(IsRegistered && "private var already registered as private");
    // Silence the warning about unused variable.
    (void)IsRegistered;

    const auto *LHSVD = cast<VarDecl>(cast<DeclRefExpr>(*ILHS)->getDecl());
    const auto *RHSVD = cast<VarDecl>(cast<DeclRefExpr>(*IRHS)->getDecl());
    QualType Type = PrivateVD->getType();
    bool isaOMPArraySectionExpr = isa<OMPArraySectionExpr>(IRef);
    if (isaOMPArraySectionExpr && Type->isVariablyModifiedType()) {
      // Store the address of the original variable associated with the LHS
      // implicit variable.
      PrivateScope.addPrivate(LHSVD, [&RedCG, Count, this]() {
        return RedCG.getSharedLValue(Count).getAddress(*this);
      });
      PrivateScope.addPrivate(
          RHSVD, [this, PrivateVD]() { return GetAddrOfLocalVar(PrivateVD); });
    } else if ((isaOMPArraySectionExpr && Type->isScalarType()) ||
               isa<ArraySubscriptExpr>(IRef)) {
      // Store the address of the original variable associated with the LHS
      // implicit variable.
      PrivateScope.addPrivate(LHSVD, [&RedCG, Count, this]() {
        return RedCG.getSharedLValue(Count).getAddress(*this);
      });
      PrivateScope.addPrivate(RHSVD, [this, PrivateVD, RHSVD]() {
        return Builder.CreateElementBitCast(GetAddrOfLocalVar(PrivateVD),
                                            ConvertTypeForMem(RHSVD->getType()),
                                            "rhs.begin");
      });
    } else {
      QualType Type = PrivateVD->getType();
      bool IsArray = getContext().getAsArrayType(Type) != nullptr;
      Address OriginalAddr = RedCG.getSharedLValue(Count).getAddress(*this);
      // Store the address of the original variable associated with the LHS
      // implicit variable.
      if (IsArray) {
        OriginalAddr = Builder.CreateElementBitCast(
            OriginalAddr, ConvertTypeForMem(LHSVD->getType()), "lhs.begin");
      }
      PrivateScope.addPrivate(LHSVD, [OriginalAddr]() { return OriginalAddr; });
      PrivateScope.addPrivate(
          RHSVD, [this, PrivateVD, RHSVD, IsArray]() {
            return IsArray
                       ? Builder.CreateElementBitCast(
                             GetAddrOfLocalVar(PrivateVD),
                             ConvertTypeForMem(RHSVD->getType()), "rhs.begin")
                       : GetAddrOfLocalVar(PrivateVD);
          });
    }
    ++ILHS;
    ++IRHS;
    ++IPriv;
    ++Count;
  }
}

void CodeGenFunction::EmitOMPReductionClauseFinal(
    const OMPExecutableDirective &D, const OpenMPDirectiveKind ReductionKind) {
  if (!HaveInsertPoint())
    return;
  llvm::SmallVector<const Expr *, 8> Privates;
  llvm::SmallVector<const Expr *, 8> LHSExprs;
  llvm::SmallVector<const Expr *, 8> RHSExprs;
  llvm::SmallVector<const Expr *, 8> ReductionOps;
  bool HasAtLeastOneReduction = false;
  for (const auto *C : D.getClausesOfKind<OMPReductionClause>()) {
    HasAtLeastOneReduction = true;
    Privates.append(C->privates().begin(), C->privates().end());
    LHSExprs.append(C->lhs_exprs().begin(), C->lhs_exprs().end());
    RHSExprs.append(C->rhs_exprs().begin(), C->rhs_exprs().end());
    ReductionOps.append(C->reduction_ops().begin(), C->reduction_ops().end());
  }
  if (HasAtLeastOneReduction) {
    bool WithNowait = D.getSingleClause<OMPNowaitClause>() ||
                      isOpenMPParallelDirective(D.getDirectiveKind()) ||
                      ReductionKind == OMPD_simd;
    bool SimpleReduction = ReductionKind == OMPD_simd;
    // Emit nowait reduction if nowait clause is present or directive is a
    // parallel directive (it always has implicit barrier).
    CGM.getOpenMPRuntime().emitReduction(
        *this, D.getEndLoc(), Privates, LHSExprs, RHSExprs, ReductionOps,
        {WithNowait, SimpleReduction, ReductionKind});
  }
}

static void emitPostUpdateForReductionClause(
    CodeGenFunction &CGF, const OMPExecutableDirective &D,
    const llvm::function_ref<llvm::Value *(CodeGenFunction &)> CondGen) {
  if (!CGF.HaveInsertPoint())
    return;
  llvm::BasicBlock *DoneBB = nullptr;
  for (const auto *C : D.getClausesOfKind<OMPReductionClause>()) {
    if (const Expr *PostUpdate = C->getPostUpdateExpr()) {
      if (!DoneBB) {
        if (llvm::Value *Cond = CondGen(CGF)) {
          // If the first post-update expression is found, emit conditional
          // block if it was requested.
          llvm::BasicBlock *ThenBB = CGF.createBasicBlock(".omp.reduction.pu");
          DoneBB = CGF.createBasicBlock(".omp.reduction.pu.done");
          CGF.Builder.CreateCondBr(Cond, ThenBB, DoneBB);
          CGF.EmitBlock(ThenBB);
        }
      }
      CGF.EmitIgnoredExpr(PostUpdate);
    }
  }
  if (DoneBB)
    CGF.EmitBlock(DoneBB, /*IsFinished=*/true);
}

namespace {
/// Codegen lambda for appending distribute lower and upper bounds to outlined
/// parallel function. This is necessary for combined constructs such as
/// 'distribute parallel for'
typedef llvm::function_ref<void(CodeGenFunction &,
                                const OMPExecutableDirective &,
                                llvm::SmallVectorImpl<llvm::Value *> &)>
    CodeGenBoundParametersTy;
} // anonymous namespace

static void emitCommonOMPParallelDirective(
    CodeGenFunction &CGF, const OMPExecutableDirective &S,
    OpenMPDirectiveKind InnermostKind, const RegionCodeGenTy &CodeGen,
    const CodeGenBoundParametersTy &CodeGenBoundParameters) {
  const CapturedStmt *CS = S.getCapturedStmt(OMPD_parallel);
  llvm::Function *OutlinedFn =
      CGF.CGM.getOpenMPRuntime().emitParallelOutlinedFunction(
          S, *CS->getCapturedDecl()->param_begin(), InnermostKind, CodeGen);
  if (const auto *NumThreadsClause = S.getSingleClause<OMPNumThreadsClause>()) {
    CodeGenFunction::RunCleanupsScope NumThreadsScope(CGF);
    llvm::Value *NumThreads =
        CGF.EmitScalarExpr(NumThreadsClause->getNumThreads(),
                           /*IgnoreResultAssign=*/true);
    CGF.CGM.getOpenMPRuntime().emitNumThreadsClause(
        CGF, NumThreads, NumThreadsClause->getBeginLoc());
  }
  if (const auto *ProcBindClause = S.getSingleClause<OMPProcBindClause>()) {
    CodeGenFunction::RunCleanupsScope ProcBindScope(CGF);
    CGF.CGM.getOpenMPRuntime().emitProcBindClause(
        CGF, ProcBindClause->getProcBindKind(), ProcBindClause->getBeginLoc());
  }
  const Expr *IfCond = nullptr;
  for (const auto *C : S.getClausesOfKind<OMPIfClause>()) {
    if (C->getNameModifier() == OMPD_unknown ||
        C->getNameModifier() == OMPD_parallel) {
      IfCond = C->getCondition();
      break;
    }
  }

  OMPParallelScope Scope(CGF, S);
  llvm::SmallVector<llvm::Value *, 16> CapturedVars;
  // Combining 'distribute' with 'for' requires sharing each 'distribute' chunk
  // lower and upper bounds with the pragma 'for' chunking mechanism.
  // The following lambda takes care of appending the lower and upper bound
  // parameters when necessary
  CodeGenBoundParameters(CGF, S, CapturedVars);
  CGF.GenerateOpenMPCapturedVars(*CS, CapturedVars);
  CGF.CGM.getOpenMPRuntime().emitParallelCall(CGF, S.getBeginLoc(), OutlinedFn,
                                              CapturedVars, IfCond);
}

static void emitEmptyBoundParameters(CodeGenFunction &,
                                     const OMPExecutableDirective &,
                                     llvm::SmallVectorImpl<llvm::Value *> &) {}

void CodeGenFunction::EmitOMPParallelDirective(const OMPParallelDirective &S) {
  // Emit parallel region as a standalone region.
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    OMPPrivateScope PrivateScope(CGF);
    bool Copyins = CGF.EmitOMPCopyinClause(S);
    (void)CGF.EmitOMPFirstprivateClause(S, PrivateScope);
    if (Copyins) {
      // Emit implicit barrier to synchronize threads and avoid data races on
      // propagation master's thread values of threadprivate variables to local
      // instances of that variables of all other implicit threads.
      CGF.CGM.getOpenMPRuntime().emitBarrierCall(
          CGF, S.getBeginLoc(), OMPD_unknown, /*EmitChecks=*/false,
          /*ForceSimpleCall=*/true);
    }
    CGF.EmitOMPPrivateClause(S, PrivateScope);
    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
    (void)PrivateScope.Privatize();
    CGF.EmitStmt(S.getCapturedStmt(OMPD_parallel)->getCapturedStmt());
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_parallel);
  };
  emitCommonOMPParallelDirective(*this, S, OMPD_parallel, CodeGen,
                                 emitEmptyBoundParameters);
  emitPostUpdateForReductionClause(*this, S,
                                   [](CodeGenFunction &) { return nullptr; });
}

static void emitBody(CodeGenFunction &CGF, const Stmt *S, const Stmt *NextLoop,
                     int MaxLevel, int Level = 0) {
  assert(Level < MaxLevel && "Too deep lookup during loop body codegen.");
  const Stmt *SimplifiedS = S->IgnoreContainers();
  if (const auto *CS = dyn_cast<CompoundStmt>(SimplifiedS)) {
    PrettyStackTraceLoc CrashInfo(
        CGF.getContext().getSourceManager(), CS->getLBracLoc(),
        "LLVM IR generation of compound statement ('{}')");

    // Keep track of the current cleanup stack depth, including debug scopes.
    CodeGenFunction::LexicalScope Scope(CGF, S->getSourceRange());
    for (const Stmt *CurStmt : CS->body())
      emitBody(CGF, CurStmt, NextLoop, MaxLevel, Level);
    return;
  }
  if (SimplifiedS == NextLoop) {
    if (const auto *For = dyn_cast<ForStmt>(SimplifiedS)) {
      S = For->getBody();
    } else {
      assert(isa<CXXForRangeStmt>(SimplifiedS) &&
             "Expected canonical for loop or range-based for loop.");
      const auto *CXXFor = cast<CXXForRangeStmt>(SimplifiedS);
      CGF.EmitStmt(CXXFor->getLoopVarStmt());
      S = CXXFor->getBody();
    }
    if (Level + 1 < MaxLevel) {
      NextLoop = OMPLoopDirective::tryToFindNextInnerLoop(
          S, /*TryImperfectlyNestedLoops=*/true);
      emitBody(CGF, S, NextLoop, MaxLevel, Level + 1);
      return;
    }
  }
  CGF.EmitStmt(S);
}

void CodeGenFunction::EmitOMPLoopBody(const OMPLoopDirective &D,
                                      JumpDest LoopExit) {
  RunCleanupsScope BodyScope(*this);
  // Update counters values on current iteration.
  for (const Expr *UE : D.updates())
    EmitIgnoredExpr(UE);
  // Update the linear variables.
  // In distribute directives only loop counters may be marked as linear, no
  // need to generate the code for them.
  if (!isOpenMPDistributeDirective(D.getDirectiveKind())) {
    for (const auto *C : D.getClausesOfKind<OMPLinearClause>()) {
      for (const Expr *UE : C->updates())
        EmitIgnoredExpr(UE);
    }
  }

  // On a continue in the body, jump to the end.
  JumpDest Continue = getJumpDestInCurrentScope("omp.body.continue");
  BreakContinueStack.push_back(BreakContinue(LoopExit, Continue));
  for (const Expr *E : D.finals_conditions()) {
    if (!E)
      continue;
    // Check that loop counter in non-rectangular nest fits into the iteration
    // space.
    llvm::BasicBlock *NextBB = createBasicBlock("omp.body.next");
    EmitBranchOnBoolExpr(E, NextBB, Continue.getBlock(),
                         getProfileCount(D.getBody()));
    EmitBlock(NextBB);
  }
  // Emit loop variables for C++ range loops.
  const Stmt *Body =
      D.getInnermostCapturedStmt()->getCapturedStmt()->IgnoreContainers();
  // Emit loop body.
  emitBody(*this, Body,
           OMPLoopDirective::tryToFindNextInnerLoop(
               Body, /*TryImperfectlyNestedLoops=*/true),
           D.getCollapsedNumber());

  // The end (updates/cleanups).
  EmitBlock(Continue.getBlock());
  BreakContinueStack.pop_back();
}

void CodeGenFunction::EmitOMPInnerLoop(
    const Stmt &S, bool RequiresCleanup, const Expr *LoopCond,
    const Expr *IncExpr,
    const llvm::function_ref<void(CodeGenFunction &)> BodyGen,
    const llvm::function_ref<void(CodeGenFunction &)> PostIncGen) {
  auto LoopExit = getJumpDestInCurrentScope("omp.inner.for.end");

  // Start the loop with a block that tests the condition.
  auto CondBlock = createBasicBlock("omp.inner.for.cond");
  EmitBlock(CondBlock);
  const SourceRange R = S.getSourceRange();
  LoopStack.push(CondBlock, SourceLocToDebugLoc(R.getBegin()),
                 SourceLocToDebugLoc(R.getEnd()));

  // If there are any cleanups between here and the loop-exit scope,
  // create a block to stage a loop exit along.
  llvm::BasicBlock *ExitBlock = LoopExit.getBlock();
  if (RequiresCleanup)
    ExitBlock = createBasicBlock("omp.inner.for.cond.cleanup");

  llvm::BasicBlock *LoopBody = createBasicBlock("omp.inner.for.body");

  // Emit condition.
  EmitBranchOnBoolExpr(LoopCond, LoopBody, ExitBlock, getProfileCount(&S));
  if (ExitBlock != LoopExit.getBlock()) {
    EmitBlock(ExitBlock);
    EmitBranchThroughCleanup(LoopExit);
  }

  EmitBlock(LoopBody);
  incrementProfileCounter(&S);

  // Create a block for the increment.
  JumpDest Continue = getJumpDestInCurrentScope("omp.inner.for.inc");
  BreakContinueStack.push_back(BreakContinue(LoopExit, Continue));

  BodyGen(*this);

  // Emit "IV = IV + 1" and a back-edge to the condition block.
  EmitBlock(Continue.getBlock());
  EmitIgnoredExpr(IncExpr);
  PostIncGen(*this);
  BreakContinueStack.pop_back();
  EmitBranch(CondBlock);
  LoopStack.pop();
  // Emit the fall-through block.
  EmitBlock(LoopExit.getBlock());
}

bool CodeGenFunction::EmitOMPLinearClauseInit(const OMPLoopDirective &D) {
  if (!HaveInsertPoint())
    return false;
  // Emit inits for the linear variables.
  bool HasLinears = false;
  for (const auto *C : D.getClausesOfKind<OMPLinearClause>()) {
    for (const Expr *Init : C->inits()) {
      HasLinears = true;
      const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(Init)->getDecl());
      if (const auto *Ref =
              dyn_cast<DeclRefExpr>(VD->getInit()->IgnoreImpCasts())) {
        AutoVarEmission Emission = EmitAutoVarAlloca(*VD);
        const auto *OrigVD = cast<VarDecl>(Ref->getDecl());
        DeclRefExpr DRE(getContext(), const_cast<VarDecl *>(OrigVD),
                        CapturedStmtInfo->lookup(OrigVD) != nullptr,
                        VD->getInit()->getType(), VK_LValue,
                        VD->getInit()->getExprLoc());
        EmitExprAsInit(&DRE, VD, MakeAddrLValue(Emission.getAllocatedAddress(),
                                                VD->getType()),
                       /*capturedByInit=*/false);
        EmitAutoVarCleanups(Emission);
      } else {
        EmitVarDecl(*VD);
      }
    }
    // Emit the linear steps for the linear clauses.
    // If a step is not constant, it is pre-calculated before the loop.
    if (const auto *CS = cast_or_null<BinaryOperator>(C->getCalcStep()))
      if (const auto *SaveRef = cast<DeclRefExpr>(CS->getLHS())) {
        EmitVarDecl(*cast<VarDecl>(SaveRef->getDecl()));
        // Emit calculation of the linear step.
        EmitIgnoredExpr(CS);
      }
  }
  return HasLinears;
}

void CodeGenFunction::EmitOMPLinearClauseFinal(
    const OMPLoopDirective &D,
    const llvm::function_ref<llvm::Value *(CodeGenFunction &)> CondGen) {
  if (!HaveInsertPoint())
    return;
  llvm::BasicBlock *DoneBB = nullptr;
  // Emit the final values of the linear variables.
  for (const auto *C : D.getClausesOfKind<OMPLinearClause>()) {
    auto IC = C->varlist_begin();
    for (const Expr *F : C->finals()) {
      if (!DoneBB) {
        if (llvm::Value *Cond = CondGen(*this)) {
          // If the first post-update expression is found, emit conditional
          // block if it was requested.
          llvm::BasicBlock *ThenBB = createBasicBlock(".omp.linear.pu");
          DoneBB = createBasicBlock(".omp.linear.pu.done");
          Builder.CreateCondBr(Cond, ThenBB, DoneBB);
          EmitBlock(ThenBB);
        }
      }
      const auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IC)->getDecl());
      DeclRefExpr DRE(getContext(), const_cast<VarDecl *>(OrigVD),
                      CapturedStmtInfo->lookup(OrigVD) != nullptr,
                      (*IC)->getType(), VK_LValue, (*IC)->getExprLoc());
      Address OrigAddr = EmitLValue(&DRE).getAddress(*this);
      CodeGenFunction::OMPPrivateScope VarScope(*this);
      VarScope.addPrivate(OrigVD, [OrigAddr]() { return OrigAddr; });
      (void)VarScope.Privatize();
      EmitIgnoredExpr(F);
      ++IC;
    }
    if (const Expr *PostUpdate = C->getPostUpdateExpr())
      EmitIgnoredExpr(PostUpdate);
  }
  if (DoneBB)
    EmitBlock(DoneBB, /*IsFinished=*/true);
}

static void emitAlignedClause(CodeGenFunction &CGF,
                              const OMPExecutableDirective &D) {
  if (!CGF.HaveInsertPoint())
    return;
  for (const auto *Clause : D.getClausesOfKind<OMPAlignedClause>()) {
    llvm::APInt ClauseAlignment(64, 0);
    if (const Expr *AlignmentExpr = Clause->getAlignment()) {
      auto *AlignmentCI =
          cast<llvm::ConstantInt>(CGF.EmitScalarExpr(AlignmentExpr));
      ClauseAlignment = AlignmentCI->getValue();
    }
    for (const Expr *E : Clause->varlists()) {
      llvm::APInt Alignment(ClauseAlignment);
      if (Alignment == 0) {
        // OpenMP [2.8.1, Description]
        // If no optional parameter is specified, implementation-defined default
        // alignments for SIMD instructions on the target platforms are assumed.
        Alignment =
            CGF.getContext()
                .toCharUnitsFromBits(CGF.getContext().getOpenMPDefaultSimdAlign(
                    E->getType()->getPointeeType()))
                .getQuantity();
      }
      assert((Alignment == 0 || Alignment.isPowerOf2()) &&
             "alignment is not power of 2");
      if (Alignment != 0) {
        llvm::Value *PtrValue = CGF.EmitScalarExpr(E);
        CGF.EmitAlignmentAssumption(
            PtrValue, E, /*No second loc needed*/ SourceLocation(),
            llvm::ConstantInt::get(CGF.getLLVMContext(), Alignment));
      }
    }
  }
}

void CodeGenFunction::EmitOMPPrivateLoopCounters(
    const OMPLoopDirective &S, CodeGenFunction::OMPPrivateScope &LoopScope) {
  if (!HaveInsertPoint())
    return;
  auto I = S.private_counters().begin();
  for (const Expr *E : S.counters()) {
    const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
    const auto *PrivateVD = cast<VarDecl>(cast<DeclRefExpr>(*I)->getDecl());
    // Emit var without initialization.
    AutoVarEmission VarEmission = EmitAutoVarAlloca(*PrivateVD);
    EmitAutoVarCleanups(VarEmission);
    LocalDeclMap.erase(PrivateVD);
    (void)LoopScope.addPrivate(VD, [&VarEmission]() {
      return VarEmission.getAllocatedAddress();
    });
    if (LocalDeclMap.count(VD) || CapturedStmtInfo->lookup(VD) ||
        VD->hasGlobalStorage()) {
      (void)LoopScope.addPrivate(PrivateVD, [this, VD, E]() {
        DeclRefExpr DRE(getContext(), const_cast<VarDecl *>(VD),
                        LocalDeclMap.count(VD) || CapturedStmtInfo->lookup(VD),
                        E->getType(), VK_LValue, E->getExprLoc());
        return EmitLValue(&DRE).getAddress(*this);
      });
    } else {
      (void)LoopScope.addPrivate(PrivateVD, [&VarEmission]() {
        return VarEmission.getAllocatedAddress();
      });
    }
    ++I;
  }
  // Privatize extra loop counters used in loops for ordered(n) clauses.
  for (const auto *C : S.getClausesOfKind<OMPOrderedClause>()) {
    if (!C->getNumForLoops())
      continue;
    for (unsigned I = S.getCollapsedNumber(),
                  E = C->getLoopNumIterations().size();
         I < E; ++I) {
      const auto *DRE = cast<DeclRefExpr>(C->getLoopCounter(I));
      const auto *VD = cast<VarDecl>(DRE->getDecl());
      // Override only those variables that can be captured to avoid re-emission
      // of the variables declared within the loops.
      if (DRE->refersToEnclosingVariableOrCapture()) {
        (void)LoopScope.addPrivate(VD, [this, DRE, VD]() {
          return CreateMemTemp(DRE->getType(), VD->getName());
        });
      }
    }
  }
}

static void emitPreCond(CodeGenFunction &CGF, const OMPLoopDirective &S,
                        const Expr *Cond, llvm::BasicBlock *TrueBlock,
                        llvm::BasicBlock *FalseBlock, uint64_t TrueCount) {
  if (!CGF.HaveInsertPoint())
    return;
  {
    CodeGenFunction::OMPPrivateScope PreCondScope(CGF);
    CGF.EmitOMPPrivateLoopCounters(S, PreCondScope);
    (void)PreCondScope.Privatize();
    // Get initial values of real counters.
    for (const Expr *I : S.inits()) {
      CGF.EmitIgnoredExpr(I);
    }
  }
  // Create temp loop control variables with their init values to support
  // non-rectangular loops.
  CodeGenFunction::OMPMapVars PreCondVars;
  for (const Expr * E: S.dependent_counters()) {
    if (!E)
      continue;
    assert(!E->getType().getNonReferenceType()->isRecordType() &&
           "dependent counter must not be an iterator.");
    const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
    Address CounterAddr =
        CGF.CreateMemTemp(VD->getType().getNonReferenceType());
    (void)PreCondVars.setVarAddr(CGF, VD, CounterAddr);
  }
  (void)PreCondVars.apply(CGF);
  for (const Expr *E : S.dependent_inits()) {
    if (!E)
      continue;
    CGF.EmitIgnoredExpr(E);
  }
  // Check that loop is executed at least one time.
  CGF.EmitBranchOnBoolExpr(Cond, TrueBlock, FalseBlock, TrueCount);
  PreCondVars.restore(CGF);
}

void CodeGenFunction::EmitOMPLinearClause(
    const OMPLoopDirective &D, CodeGenFunction::OMPPrivateScope &PrivateScope) {
  if (!HaveInsertPoint())
    return;
  llvm::DenseSet<const VarDecl *> SIMDLCVs;
  if (isOpenMPSimdDirective(D.getDirectiveKind())) {
    const auto *LoopDirective = cast<OMPLoopDirective>(&D);
    for (const Expr *C : LoopDirective->counters()) {
      SIMDLCVs.insert(
          cast<VarDecl>(cast<DeclRefExpr>(C)->getDecl())->getCanonicalDecl());
    }
  }
  for (const auto *C : D.getClausesOfKind<OMPLinearClause>()) {
    auto CurPrivate = C->privates().begin();
    for (const Expr *E : C->varlists()) {
      const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
      const auto *PrivateVD =
          cast<VarDecl>(cast<DeclRefExpr>(*CurPrivate)->getDecl());
      if (!SIMDLCVs.count(VD->getCanonicalDecl())) {
        bool IsRegistered = PrivateScope.addPrivate(VD, [this, PrivateVD]() {
          // Emit private VarDecl with copy init.
          EmitVarDecl(*PrivateVD);
          return GetAddrOfLocalVar(PrivateVD);
        });
        assert(IsRegistered && "linear var already registered as private");
        // Silence the warning about unused variable.
        (void)IsRegistered;
      } else {
        EmitVarDecl(*PrivateVD);
      }
      ++CurPrivate;
    }
  }
}

static void emitSimdlenSafelenClause(CodeGenFunction &CGF,
                                     const OMPExecutableDirective &D,
                                     bool IsMonotonic) {
  if (!CGF.HaveInsertPoint())
    return;
  if (const auto *C = D.getSingleClause<OMPSimdlenClause>()) {
    RValue Len = CGF.EmitAnyExpr(C->getSimdlen(), AggValueSlot::ignored(),
                                 /*ignoreResult=*/true);
    auto *Val = cast<llvm::ConstantInt>(Len.getScalarVal());
    CGF.LoopStack.setVectorizeWidth(Val->getZExtValue());
    // In presence of finite 'safelen', it may be unsafe to mark all
    // the memory instructions parallel, because loop-carried
    // dependences of 'safelen' iterations are possible.
    if (!IsMonotonic)
      CGF.LoopStack.setParallel(!D.getSingleClause<OMPSafelenClause>());
  } else if (const auto *C = D.getSingleClause<OMPSafelenClause>()) {
    RValue Len = CGF.EmitAnyExpr(C->getSafelen(), AggValueSlot::ignored(),
                                 /*ignoreResult=*/true);
    auto *Val = cast<llvm::ConstantInt>(Len.getScalarVal());
    CGF.LoopStack.setVectorizeWidth(Val->getZExtValue());
    // In presence of finite 'safelen', it may be unsafe to mark all
    // the memory instructions parallel, because loop-carried
    // dependences of 'safelen' iterations are possible.
    CGF.LoopStack.setParallel(/*Enable=*/false);
  }
}

void CodeGenFunction::EmitOMPSimdInit(const OMPLoopDirective &D,
                                      bool IsMonotonic) {
  // Walk clauses and process safelen/lastprivate.
  LoopStack.setParallel(!IsMonotonic);
  LoopStack.setVectorizeEnable();
  emitSimdlenSafelenClause(*this, D, IsMonotonic);
}

void CodeGenFunction::EmitOMPSimdFinal(
    const OMPLoopDirective &D,
    const llvm::function_ref<llvm::Value *(CodeGenFunction &)> CondGen) {
  if (!HaveInsertPoint())
    return;
  llvm::BasicBlock *DoneBB = nullptr;
  auto IC = D.counters().begin();
  auto IPC = D.private_counters().begin();
  for (const Expr *F : D.finals()) {
    const auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>((*IC))->getDecl());
    const auto *PrivateVD = cast<VarDecl>(cast<DeclRefExpr>((*IPC))->getDecl());
    const auto *CED = dyn_cast<OMPCapturedExprDecl>(OrigVD);
    if (LocalDeclMap.count(OrigVD) || CapturedStmtInfo->lookup(OrigVD) ||
        OrigVD->hasGlobalStorage() || CED) {
      if (!DoneBB) {
        if (llvm::Value *Cond = CondGen(*this)) {
          // If the first post-update expression is found, emit conditional
          // block if it was requested.
          llvm::BasicBlock *ThenBB = createBasicBlock(".omp.final.then");
          DoneBB = createBasicBlock(".omp.final.done");
          Builder.CreateCondBr(Cond, ThenBB, DoneBB);
          EmitBlock(ThenBB);
        }
      }
      Address OrigAddr = Address::invalid();
      if (CED) {
        OrigAddr =
            EmitLValue(CED->getInit()->IgnoreImpCasts()).getAddress(*this);
      } else {
        DeclRefExpr DRE(getContext(), const_cast<VarDecl *>(PrivateVD),
                        /*RefersToEnclosingVariableOrCapture=*/false,
                        (*IPC)->getType(), VK_LValue, (*IPC)->getExprLoc());
        OrigAddr = EmitLValue(&DRE).getAddress(*this);
      }
      OMPPrivateScope VarScope(*this);
      VarScope.addPrivate(OrigVD, [OrigAddr]() { return OrigAddr; });
      (void)VarScope.Privatize();
      EmitIgnoredExpr(F);
    }
    ++IC;
    ++IPC;
  }
  if (DoneBB)
    EmitBlock(DoneBB, /*IsFinished=*/true);
}

static void emitOMPLoopBodyWithStopPoint(CodeGenFunction &CGF,
                                         const OMPLoopDirective &S,
                                         CodeGenFunction::JumpDest LoopExit) {
  CGF.EmitOMPLoopBody(S, LoopExit);
  CGF.EmitStopPoint(&S);
}

/// Emit a helper variable and return corresponding lvalue.
static LValue EmitOMPHelperVar(CodeGenFunction &CGF,
                               const DeclRefExpr *Helper) {
  auto VDecl = cast<VarDecl>(Helper->getDecl());
  CGF.EmitVarDecl(*VDecl);
  return CGF.EmitLValue(Helper);
}

static void emitCommonSimdLoop(CodeGenFunction &CGF, const OMPLoopDirective &S,
                               const RegionCodeGenTy &SimdInitGen,
                               const RegionCodeGenTy &BodyCodeGen) {
  auto &&ThenGen = [&SimdInitGen, &BodyCodeGen](CodeGenFunction &CGF,
                                                PrePostActionTy &) {
    CodeGenFunction::OMPLocalDeclMapRAII Scope(CGF);
    SimdInitGen(CGF);

    BodyCodeGen(CGF);
  };
  auto &&ElseGen = [&BodyCodeGen](CodeGenFunction &CGF, PrePostActionTy &) {
    CodeGenFunction::OMPLocalDeclMapRAII Scope(CGF);
    CGF.LoopStack.setVectorizeEnable(/*Enable=*/false);

    BodyCodeGen(CGF);
  };
  const Expr *IfCond = nullptr;
  for (const auto *C : S.getClausesOfKind<OMPIfClause>()) {
    if (CGF.getLangOpts().OpenMP >= 50 &&
        (C->getNameModifier() == OMPD_unknown ||
         C->getNameModifier() == OMPD_simd)) {
      IfCond = C->getCondition();
      break;
    }
  }
  if (IfCond) {
    CGF.CGM.getOpenMPRuntime().emitIfClause(CGF, IfCond, ThenGen, ElseGen);
  } else {
    RegionCodeGenTy ThenRCG(ThenGen);
    ThenRCG(CGF);
  }
}

static void emitOMPSimdRegion(CodeGenFunction &CGF, const OMPLoopDirective &S,
                              PrePostActionTy &Action) {
  Action.Enter(CGF);
  assert(isOpenMPSimdDirective(S.getDirectiveKind()) &&
         "Expected simd directive");
  OMPLoopScope PreInitScope(CGF, S);
  // if (PreCond) {
  //   for (IV in 0..LastIteration) BODY;
  //   <Final counter/linear vars updates>;
  // }
  //
  if (isOpenMPDistributeDirective(S.getDirectiveKind()) ||
      isOpenMPWorksharingDirective(S.getDirectiveKind()) ||
      isOpenMPTaskLoopDirective(S.getDirectiveKind())) {
    (void)EmitOMPHelperVar(CGF, cast<DeclRefExpr>(S.getLowerBoundVariable()));
    (void)EmitOMPHelperVar(CGF, cast<DeclRefExpr>(S.getUpperBoundVariable()));
  }

  // Emit: if (PreCond) - begin.
  // If the condition constant folds and can be elided, avoid emitting the
  // whole loop.
  bool CondConstant;
  llvm::BasicBlock *ContBlock = nullptr;
  if (CGF.ConstantFoldsToSimpleInteger(S.getPreCond(), CondConstant)) {
    if (!CondConstant)
      return;
  } else {
    llvm::BasicBlock *ThenBlock = CGF.createBasicBlock("simd.if.then");
    ContBlock = CGF.createBasicBlock("simd.if.end");
    emitPreCond(CGF, S, S.getPreCond(), ThenBlock, ContBlock,
                CGF.getProfileCount(&S));
    CGF.EmitBlock(ThenBlock);
    CGF.incrementProfileCounter(&S);
  }

  // Emit the loop iteration variable.
  const Expr *IVExpr = S.getIterationVariable();
  const auto *IVDecl = cast<VarDecl>(cast<DeclRefExpr>(IVExpr)->getDecl());
  CGF.EmitVarDecl(*IVDecl);
  CGF.EmitIgnoredExpr(S.getInit());

  // Emit the iterations count variable.
  // If it is not a variable, Sema decided to calculate iterations count on
  // each iteration (e.g., it is foldable into a constant).
  if (const auto *LIExpr = dyn_cast<DeclRefExpr>(S.getLastIteration())) {
    CGF.EmitVarDecl(*cast<VarDecl>(LIExpr->getDecl()));
    // Emit calculation of the iterations count.
    CGF.EmitIgnoredExpr(S.getCalcLastIteration());
  }

  emitAlignedClause(CGF, S);
  (void)CGF.EmitOMPLinearClauseInit(S);
  {
    CodeGenFunction::OMPPrivateScope LoopScope(CGF);
    CGF.EmitOMPPrivateLoopCounters(S, LoopScope);
    CGF.EmitOMPLinearClause(S, LoopScope);
    CGF.EmitOMPPrivateClause(S, LoopScope);
    CGF.EmitOMPReductionClauseInit(S, LoopScope);
    bool HasLastprivateClause = CGF.EmitOMPLastprivateClauseInit(S, LoopScope);
    (void)LoopScope.Privatize();
    if (isOpenMPTargetExecutionDirective(S.getDirectiveKind()))
      CGF.CGM.getOpenMPRuntime().adjustTargetSpecificDataForLambdas(CGF, S);

    emitCommonSimdLoop(
        CGF, S,
        [&S](CodeGenFunction &CGF, PrePostActionTy &) {
          CGF.EmitOMPSimdInit(S);
        },
        [&S, &LoopScope](CodeGenFunction &CGF, PrePostActionTy &) {
          CGF.EmitOMPInnerLoop(
              S, LoopScope.requiresCleanups(), S.getCond(), S.getInc(),
              [&S](CodeGenFunction &CGF) {
                CGF.EmitOMPLoopBody(S, CodeGenFunction::JumpDest());
                CGF.EmitStopPoint(&S);
              },
              [](CodeGenFunction &) {});
        });
    CGF.EmitOMPSimdFinal(S, [](CodeGenFunction &) { return nullptr; });
    // Emit final copy of the lastprivate variables at the end of loops.
    if (HasLastprivateClause)
      CGF.EmitOMPLastprivateClauseFinal(S, /*NoFinals=*/true);
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_simd);
    emitPostUpdateForReductionClause(CGF, S,
                                     [](CodeGenFunction &) { return nullptr; });
  }
  CGF.EmitOMPLinearClauseFinal(S, [](CodeGenFunction &) { return nullptr; });
  // Emit: if (PreCond) - end.
  if (ContBlock) {
    CGF.EmitBranch(ContBlock);
    CGF.EmitBlock(ContBlock, true);
  }
}

void CodeGenFunction::EmitOMPSimdDirective(const OMPSimdDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitOMPSimdRegion(CGF, S, Action);
  };
  OMPLexicalScope Scope(*this, S, OMPD_unknown);
  CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_simd, CodeGen);
}

void CodeGenFunction::EmitOMPOuterLoop(
    bool DynamicOrOrdered, bool IsMonotonic, const OMPLoopDirective &S,
    CodeGenFunction::OMPPrivateScope &LoopScope,
    const CodeGenFunction::OMPLoopArguments &LoopArgs,
    const CodeGenFunction::CodeGenLoopTy &CodeGenLoop,
    const CodeGenFunction::CodeGenOrderedTy &CodeGenOrdered) {
  CGOpenMPRuntime &RT = CGM.getOpenMPRuntime();

  const Expr *IVExpr = S.getIterationVariable();
  const unsigned IVSize = getContext().getTypeSize(IVExpr->getType());
  const bool IVSigned = IVExpr->getType()->hasSignedIntegerRepresentation();

  JumpDest LoopExit = getJumpDestInCurrentScope("omp.dispatch.end");

  // Start the loop with a block that tests the condition.
  llvm::BasicBlock *CondBlock = createBasicBlock("omp.dispatch.cond");
  EmitBlock(CondBlock);
  const SourceRange R = S.getSourceRange();
  LoopStack.push(CondBlock, SourceLocToDebugLoc(R.getBegin()),
                 SourceLocToDebugLoc(R.getEnd()));

  llvm::Value *BoolCondVal = nullptr;
  if (!DynamicOrOrdered) {
    // UB = min(UB, GlobalUB) or
    // UB = min(UB, PrevUB) for combined loop sharing constructs (e.g.
    // 'distribute parallel for')
    EmitIgnoredExpr(LoopArgs.EUB);
    // IV = LB
    EmitIgnoredExpr(LoopArgs.Init);
    // IV < UB
    BoolCondVal = EvaluateExprAsBool(LoopArgs.Cond);
  } else {
    BoolCondVal =
        RT.emitForNext(*this, S.getBeginLoc(), IVSize, IVSigned, LoopArgs.IL,
                       LoopArgs.LB, LoopArgs.UB, LoopArgs.ST);
  }

  // If there are any cleanups between here and the loop-exit scope,
  // create a block to stage a loop exit along.
  llvm::BasicBlock *ExitBlock = LoopExit.getBlock();
  if (LoopScope.requiresCleanups())
    ExitBlock = createBasicBlock("omp.dispatch.cleanup");

  llvm::BasicBlock *LoopBody = createBasicBlock("omp.dispatch.body");
  Builder.CreateCondBr(BoolCondVal, LoopBody, ExitBlock);
  if (ExitBlock != LoopExit.getBlock()) {
    EmitBlock(ExitBlock);
    EmitBranchThroughCleanup(LoopExit);
  }
  EmitBlock(LoopBody);

  // Emit "IV = LB" (in case of static schedule, we have already calculated new
  // LB for loop condition and emitted it above).
  if (DynamicOrOrdered)
    EmitIgnoredExpr(LoopArgs.Init);

  // Create a block for the increment.
  JumpDest Continue = getJumpDestInCurrentScope("omp.dispatch.inc");
  BreakContinueStack.push_back(BreakContinue(LoopExit, Continue));

  emitCommonSimdLoop(
      *this, S,
      [&S, IsMonotonic](CodeGenFunction &CGF, PrePostActionTy &) {
        // Generate !llvm.loop.parallel metadata for loads and stores for loops
        // with dynamic/guided scheduling and without ordered clause.
        if (!isOpenMPSimdDirective(S.getDirectiveKind()))
          CGF.LoopStack.setParallel(!IsMonotonic);
        else
          CGF.EmitOMPSimdInit(S, IsMonotonic);
      },
      [&S, &LoopArgs, LoopExit, &CodeGenLoop, IVSize, IVSigned, &CodeGenOrdered,
       &LoopScope](CodeGenFunction &CGF, PrePostActionTy &) {
        SourceLocation Loc = S.getBeginLoc();
        // when 'distribute' is not combined with a 'for':
        // while (idx <= UB) { BODY; ++idx; }
        // when 'distribute' is combined with a 'for'
        // (e.g. 'distribute parallel for')
        // while (idx <= UB) { <CodeGen rest of pragma>; idx += ST; }
        CGF.EmitOMPInnerLoop(
            S, LoopScope.requiresCleanups(), LoopArgs.Cond, LoopArgs.IncExpr,
            [&S, LoopExit, &CodeGenLoop](CodeGenFunction &CGF) {
              CodeGenLoop(CGF, S, LoopExit);
            },
            [IVSize, IVSigned, Loc, &CodeGenOrdered](CodeGenFunction &CGF) {
              CodeGenOrdered(CGF, Loc, IVSize, IVSigned);
            });
      });

  EmitBlock(Continue.getBlock());
  BreakContinueStack.pop_back();
  if (!DynamicOrOrdered) {
    // Emit "LB = LB + Stride", "UB = UB + Stride".
    EmitIgnoredExpr(LoopArgs.NextLB);
    EmitIgnoredExpr(LoopArgs.NextUB);
  }

  EmitBranch(CondBlock);
  LoopStack.pop();
  // Emit the fall-through block.
  EmitBlock(LoopExit.getBlock());

  // Tell the runtime we are done.
  auto &&CodeGen = [DynamicOrOrdered, &S](CodeGenFunction &CGF) {
    if (!DynamicOrOrdered)
      CGF.CGM.getOpenMPRuntime().emitForStaticFinish(CGF, S.getEndLoc(),
                                                     S.getDirectiveKind());
  };
  OMPCancelStack.emitExit(*this, S.getDirectiveKind(), CodeGen);
}

void CodeGenFunction::EmitOMPForOuterLoop(
    const OpenMPScheduleTy &ScheduleKind, bool IsMonotonic,
    const OMPLoopDirective &S, OMPPrivateScope &LoopScope, bool Ordered,
    const OMPLoopArguments &LoopArgs,
    const CodeGenDispatchBoundsTy &CGDispatchBounds) {
  CGOpenMPRuntime &RT = CGM.getOpenMPRuntime();

  // Dynamic scheduling of the outer loop (dynamic, guided, auto, runtime).
  const bool DynamicOrOrdered =
      Ordered || RT.isDynamic(ScheduleKind.Schedule);

  assert((Ordered ||
          !RT.isStaticNonchunked(ScheduleKind.Schedule,
                                 LoopArgs.Chunk != nullptr)) &&
         "static non-chunked schedule does not need outer loop");

  // Emit outer loop.
  //
  // OpenMP [2.7.1, Loop Construct, Description, table 2-1]
  // When schedule(dynamic,chunk_size) is specified, the iterations are
  // distributed to threads in the team in chunks as the threads request them.
  // Each thread executes a chunk of iterations, then requests another chunk,
  // until no chunks remain to be distributed. Each chunk contains chunk_size
  // iterations, except for the last chunk to be distributed, which may have
  // fewer iterations. When no chunk_size is specified, it defaults to 1.
  //
  // When schedule(guided,chunk_size) is specified, the iterations are assigned
  // to threads in the team in chunks as the executing threads request them.
  // Each thread executes a chunk of iterations, then requests another chunk,
  // until no chunks remain to be assigned. For a chunk_size of 1, the size of
  // each chunk is proportional to the number of unassigned iterations divided
  // by the number of threads in the team, decreasing to 1. For a chunk_size
  // with value k (greater than 1), the size of each chunk is determined in the
  // same way, with the restriction that the chunks do not contain fewer than k
  // iterations (except for the last chunk to be assigned, which may have fewer
  // than k iterations).
  //
  // When schedule(auto) is specified, the decision regarding scheduling is
  // delegated to the compiler and/or runtime system. The programmer gives the
  // implementation the freedom to choose any possible mapping of iterations to
  // threads in the team.
  //
  // When schedule(runtime) is specified, the decision regarding scheduling is
  // deferred until run time, and the schedule and chunk size are taken from the
  // run-sched-var ICV. If the ICV is set to auto, the schedule is
  // implementation defined
  //
  // while(__kmpc_dispatch_next(&LB, &UB)) {
  //   idx = LB;
  //   while (idx <= UB) { BODY; ++idx;
  //   __kmpc_dispatch_fini_(4|8)[u](); // For ordered loops only.
  //   } // inner loop
  // }
  //
  // OpenMP [2.7.1, Loop Construct, Description, table 2-1]
  // When schedule(static, chunk_size) is specified, iterations are divided into
  // chunks of size chunk_size, and the chunks are assigned to the threads in
  // the team in a round-robin fashion in the order of the thread number.
  //
  // while(UB = min(UB, GlobalUB), idx = LB, idx < UB) {
  //   while (idx <= UB) { BODY; ++idx; } // inner loop
  //   LB = LB + ST;
  //   UB = UB + ST;
  // }
  //

  const Expr *IVExpr = S.getIterationVariable();
  const unsigned IVSize = getContext().getTypeSize(IVExpr->getType());
  const bool IVSigned = IVExpr->getType()->hasSignedIntegerRepresentation();

  if (DynamicOrOrdered) {
    const std::pair<llvm::Value *, llvm::Value *> DispatchBounds =
        CGDispatchBounds(*this, S, LoopArgs.LB, LoopArgs.UB);
    llvm::Value *LBVal = DispatchBounds.first;
    llvm::Value *UBVal = DispatchBounds.second;
    CGOpenMPRuntime::DispatchRTInput DipatchRTInputValues = {LBVal, UBVal,
                                                             LoopArgs.Chunk};
    RT.emitForDispatchInit(*this, S.getBeginLoc(), ScheduleKind, IVSize,
                           IVSigned, Ordered, DipatchRTInputValues);
  } else {
    CGOpenMPRuntime::StaticRTInput StaticInit(
        IVSize, IVSigned, Ordered, LoopArgs.IL, LoopArgs.LB, LoopArgs.UB,
        LoopArgs.ST, LoopArgs.Chunk);
    RT.emitForStaticInit(*this, S.getBeginLoc(), S.getDirectiveKind(),
                         ScheduleKind, StaticInit);
  }

  auto &&CodeGenOrdered = [Ordered](CodeGenFunction &CGF, SourceLocation Loc,
                                    const unsigned IVSize,
                                    const bool IVSigned) {
    if (Ordered) {
      CGF.CGM.getOpenMPRuntime().emitForOrderedIterationEnd(CGF, Loc, IVSize,
                                                            IVSigned);
    }
  };

  OMPLoopArguments OuterLoopArgs(LoopArgs.LB, LoopArgs.UB, LoopArgs.ST,
                                 LoopArgs.IL, LoopArgs.Chunk, LoopArgs.EUB);
  OuterLoopArgs.IncExpr = S.getInc();
  OuterLoopArgs.Init = S.getInit();
  OuterLoopArgs.Cond = S.getCond();
  OuterLoopArgs.NextLB = S.getNextLowerBound();
  OuterLoopArgs.NextUB = S.getNextUpperBound();
  EmitOMPOuterLoop(DynamicOrOrdered, IsMonotonic, S, LoopScope, OuterLoopArgs,
                   emitOMPLoopBodyWithStopPoint, CodeGenOrdered);
}

static void emitEmptyOrdered(CodeGenFunction &, SourceLocation Loc,
                             const unsigned IVSize, const bool IVSigned) {}

void CodeGenFunction::EmitOMPDistributeOuterLoop(
    OpenMPDistScheduleClauseKind ScheduleKind, const OMPLoopDirective &S,
    OMPPrivateScope &LoopScope, const OMPLoopArguments &LoopArgs,
    const CodeGenLoopTy &CodeGenLoopContent) {

  CGOpenMPRuntime &RT = CGM.getOpenMPRuntime();

  // Emit outer loop.
  // Same behavior as a OMPForOuterLoop, except that schedule cannot be
  // dynamic
  //

  const Expr *IVExpr = S.getIterationVariable();
  const unsigned IVSize = getContext().getTypeSize(IVExpr->getType());
  const bool IVSigned = IVExpr->getType()->hasSignedIntegerRepresentation();

  CGOpenMPRuntime::StaticRTInput StaticInit(
      IVSize, IVSigned, /* Ordered = */ false, LoopArgs.IL, LoopArgs.LB,
      LoopArgs.UB, LoopArgs.ST, LoopArgs.Chunk);
  RT.emitDistributeStaticInit(*this, S.getBeginLoc(), ScheduleKind, StaticInit);

  // for combined 'distribute' and 'for' the increment expression of distribute
  // is stored in DistInc. For 'distribute' alone, it is in Inc.
  Expr *IncExpr;
  if (isOpenMPLoopBoundSharingDirective(S.getDirectiveKind()))
    IncExpr = S.getDistInc();
  else
    IncExpr = S.getInc();

  // this routine is shared by 'omp distribute parallel for' and
  // 'omp distribute': select the right EUB expression depending on the
  // directive
  OMPLoopArguments OuterLoopArgs;
  OuterLoopArgs.LB = LoopArgs.LB;
  OuterLoopArgs.UB = LoopArgs.UB;
  OuterLoopArgs.ST = LoopArgs.ST;
  OuterLoopArgs.IL = LoopArgs.IL;
  OuterLoopArgs.Chunk = LoopArgs.Chunk;
  OuterLoopArgs.EUB = isOpenMPLoopBoundSharingDirective(S.getDirectiveKind())
                          ? S.getCombinedEnsureUpperBound()
                          : S.getEnsureUpperBound();
  OuterLoopArgs.IncExpr = IncExpr;
  OuterLoopArgs.Init = isOpenMPLoopBoundSharingDirective(S.getDirectiveKind())
                           ? S.getCombinedInit()
                           : S.getInit();
  OuterLoopArgs.Cond = isOpenMPLoopBoundSharingDirective(S.getDirectiveKind())
                           ? S.getCombinedCond()
                           : S.getCond();
  OuterLoopArgs.NextLB = isOpenMPLoopBoundSharingDirective(S.getDirectiveKind())
                             ? S.getCombinedNextLowerBound()
                             : S.getNextLowerBound();
  OuterLoopArgs.NextUB = isOpenMPLoopBoundSharingDirective(S.getDirectiveKind())
                             ? S.getCombinedNextUpperBound()
                             : S.getNextUpperBound();

  EmitOMPOuterLoop(/* DynamicOrOrdered = */ false, /* IsMonotonic = */ false, S,
                   LoopScope, OuterLoopArgs, CodeGenLoopContent,
                   emitEmptyOrdered);
}

static std::pair<LValue, LValue>
emitDistributeParallelForInnerBounds(CodeGenFunction &CGF,
                                     const OMPExecutableDirective &S) {
  const OMPLoopDirective &LS = cast<OMPLoopDirective>(S);
  LValue LB =
      EmitOMPHelperVar(CGF, cast<DeclRefExpr>(LS.getLowerBoundVariable()));
  LValue UB =
      EmitOMPHelperVar(CGF, cast<DeclRefExpr>(LS.getUpperBoundVariable()));

  // When composing 'distribute' with 'for' (e.g. as in 'distribute
  // parallel for') we need to use the 'distribute'
  // chunk lower and upper bounds rather than the whole loop iteration
  // space. These are parameters to the outlined function for 'parallel'
  // and we copy the bounds of the previous schedule into the
  // the current ones.
  LValue PrevLB = CGF.EmitLValue(LS.getPrevLowerBoundVariable());
  LValue PrevUB = CGF.EmitLValue(LS.getPrevUpperBoundVariable());
  llvm::Value *PrevLBVal = CGF.EmitLoadOfScalar(
      PrevLB, LS.getPrevLowerBoundVariable()->getExprLoc());
  PrevLBVal = CGF.EmitScalarConversion(
      PrevLBVal, LS.getPrevLowerBoundVariable()->getType(),
      LS.getIterationVariable()->getType(),
      LS.getPrevLowerBoundVariable()->getExprLoc());
  llvm::Value *PrevUBVal = CGF.EmitLoadOfScalar(
      PrevUB, LS.getPrevUpperBoundVariable()->getExprLoc());
  PrevUBVal = CGF.EmitScalarConversion(
      PrevUBVal, LS.getPrevUpperBoundVariable()->getType(),
      LS.getIterationVariable()->getType(),
      LS.getPrevUpperBoundVariable()->getExprLoc());

  CGF.EmitStoreOfScalar(PrevLBVal, LB);
  CGF.EmitStoreOfScalar(PrevUBVal, UB);

  return {LB, UB};
}

/// if the 'for' loop has a dispatch schedule (e.g. dynamic, guided) then
/// we need to use the LB and UB expressions generated by the worksharing
/// code generation support, whereas in non combined situations we would
/// just emit 0 and the LastIteration expression
/// This function is necessary due to the difference of the LB and UB
/// types for the RT emission routines for 'for_static_init' and
/// 'for_dispatch_init'
static std::pair<llvm::Value *, llvm::Value *>
emitDistributeParallelForDispatchBounds(CodeGenFunction &CGF,
                                        const OMPExecutableDirective &S,
                                        Address LB, Address UB) {
  const OMPLoopDirective &LS = cast<OMPLoopDirective>(S);
  const Expr *IVExpr = LS.getIterationVariable();
  // when implementing a dynamic schedule for a 'for' combined with a
  // 'distribute' (e.g. 'distribute parallel for'), the 'for' loop
  // is not normalized as each team only executes its own assigned
  // distribute chunk
  QualType IteratorTy = IVExpr->getType();
  llvm::Value *LBVal =
      CGF.EmitLoadOfScalar(LB, /*Volatile=*/false, IteratorTy, S.getBeginLoc());
  llvm::Value *UBVal =
      CGF.EmitLoadOfScalar(UB, /*Volatile=*/false, IteratorTy, S.getBeginLoc());
  return {LBVal, UBVal};
}

static void emitDistributeParallelForDistributeInnerBoundParams(
    CodeGenFunction &CGF, const OMPExecutableDirective &S,
    llvm::SmallVectorImpl<llvm::Value *> &CapturedVars) {
  const auto &Dir = cast<OMPLoopDirective>(S);
  LValue LB =
      CGF.EmitLValue(cast<DeclRefExpr>(Dir.getCombinedLowerBoundVariable()));
  llvm::Value *LBCast =
      CGF.Builder.CreateIntCast(CGF.Builder.CreateLoad(LB.getAddress(CGF)),
                                CGF.SizeTy, /*isSigned=*/false);
  CapturedVars.push_back(LBCast);
  LValue UB =
      CGF.EmitLValue(cast<DeclRefExpr>(Dir.getCombinedUpperBoundVariable()));

  llvm::Value *UBCast =
      CGF.Builder.CreateIntCast(CGF.Builder.CreateLoad(UB.getAddress(CGF)),
                                CGF.SizeTy, /*isSigned=*/false);
  CapturedVars.push_back(UBCast);
}

static void
emitInnerParallelForWhenCombined(CodeGenFunction &CGF,
                                 const OMPLoopDirective &S,
                                 CodeGenFunction::JumpDest LoopExit) {
  auto &&CGInlinedWorksharingLoop = [&S](CodeGenFunction &CGF,
                                         PrePostActionTy &Action) {
    Action.Enter(CGF);
    bool HasCancel = false;
    if (!isOpenMPSimdDirective(S.getDirectiveKind())) {
      if (const auto *D = dyn_cast<OMPTeamsDistributeParallelForDirective>(&S))
        HasCancel = D->hasCancel();
      else if (const auto *D = dyn_cast<OMPDistributeParallelForDirective>(&S))
        HasCancel = D->hasCancel();
      else if (const auto *D =
                   dyn_cast<OMPTargetTeamsDistributeParallelForDirective>(&S))
        HasCancel = D->hasCancel();
    }
    CodeGenFunction::OMPCancelStackRAII CancelRegion(CGF, S.getDirectiveKind(),
                                                     HasCancel);
    CGF.EmitOMPWorksharingLoop(S, S.getPrevEnsureUpperBound(),
                               emitDistributeParallelForInnerBounds,
                               emitDistributeParallelForDispatchBounds);
  };

  emitCommonOMPParallelDirective(
      CGF, S,
      isOpenMPSimdDirective(S.getDirectiveKind()) ? OMPD_for_simd : OMPD_for,
      CGInlinedWorksharingLoop,
      emitDistributeParallelForDistributeInnerBoundParams);
}

void CodeGenFunction::EmitOMPDistributeParallelForDirective(
    const OMPDistributeParallelForDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitOMPDistributeLoop(S, emitInnerParallelForWhenCombined,
                              S.getDistInc());
  };
  OMPLexicalScope Scope(*this, S, OMPD_parallel);
  CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_distribute, CodeGen);
}

void CodeGenFunction::EmitOMPDistributeParallelForSimdDirective(
    const OMPDistributeParallelForSimdDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitOMPDistributeLoop(S, emitInnerParallelForWhenCombined,
                              S.getDistInc());
  };
  OMPLexicalScope Scope(*this, S, OMPD_parallel);
  CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_distribute, CodeGen);
}

void CodeGenFunction::EmitOMPDistributeSimdDirective(
    const OMPDistributeSimdDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitOMPDistributeLoop(S, emitOMPLoopBodyWithStopPoint, S.getInc());
  };
  OMPLexicalScope Scope(*this, S, OMPD_unknown);
  CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_simd, CodeGen);
}

void CodeGenFunction::EmitOMPTargetSimdDeviceFunction(
    CodeGenModule &CGM, StringRef ParentName, const OMPTargetSimdDirective &S) {
  // Emit SPMD target parallel for region as a standalone region.
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitOMPSimdRegion(CGF, S, Action);
  };
  llvm::Function *Fn;
  llvm::Constant *Addr;
  // Emit target region as a standalone region.
  CGM.getOpenMPRuntime().emitTargetOutlinedFunction(
      S, ParentName, Fn, Addr, /*IsOffloadEntry=*/true, CodeGen);
  assert(Fn && Addr && "Target device function emission failed.");
}

void CodeGenFunction::EmitOMPTargetSimdDirective(
    const OMPTargetSimdDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitOMPSimdRegion(CGF, S, Action);
  };
  emitCommonOMPTargetDirective(*this, S, CodeGen);
}

namespace {
  struct ScheduleKindModifiersTy {
    OpenMPScheduleClauseKind Kind;
    OpenMPScheduleClauseModifier M1;
    OpenMPScheduleClauseModifier M2;
    ScheduleKindModifiersTy(OpenMPScheduleClauseKind Kind,
                            OpenMPScheduleClauseModifier M1,
                            OpenMPScheduleClauseModifier M2)
        : Kind(Kind), M1(M1), M2(M2) {}
  };
} // namespace

bool CodeGenFunction::EmitOMPWorksharingLoop(
    const OMPLoopDirective &S, Expr *EUB,
    const CodeGenLoopBoundsTy &CodeGenLoopBounds,
    const CodeGenDispatchBoundsTy &CGDispatchBounds) {
  // Emit the loop iteration variable.
  const auto *IVExpr = cast<DeclRefExpr>(S.getIterationVariable());
  const auto *IVDecl = cast<VarDecl>(IVExpr->getDecl());
  EmitVarDecl(*IVDecl);

  // Emit the iterations count variable.
  // If it is not a variable, Sema decided to calculate iterations count on each
  // iteration (e.g., it is foldable into a constant).
  if (const auto *LIExpr = dyn_cast<DeclRefExpr>(S.getLastIteration())) {
    EmitVarDecl(*cast<VarDecl>(LIExpr->getDecl()));
    // Emit calculation of the iterations count.
    EmitIgnoredExpr(S.getCalcLastIteration());
  }

  CGOpenMPRuntime &RT = CGM.getOpenMPRuntime();

  bool HasLastprivateClause;
  // Check pre-condition.
  {
    OMPLoopScope PreInitScope(*this, S);
    // Skip the entire loop if we don't meet the precondition.
    // If the condition constant folds and can be elided, avoid emitting the
    // whole loop.
    bool CondConstant;
    llvm::BasicBlock *ContBlock = nullptr;
    if (ConstantFoldsToSimpleInteger(S.getPreCond(), CondConstant)) {
      if (!CondConstant)
        return false;
    } else {
      llvm::BasicBlock *ThenBlock = createBasicBlock("omp.precond.then");
      ContBlock = createBasicBlock("omp.precond.end");
      emitPreCond(*this, S, S.getPreCond(), ThenBlock, ContBlock,
                  getProfileCount(&S));
      EmitBlock(ThenBlock);
      incrementProfileCounter(&S);
    }

    RunCleanupsScope DoacrossCleanupScope(*this);
    bool Ordered = false;
    if (const auto *OrderedClause = S.getSingleClause<OMPOrderedClause>()) {
      if (OrderedClause->getNumForLoops())
        RT.emitDoacrossInit(*this, S, OrderedClause->getLoopNumIterations());
      else
        Ordered = true;
    }

    llvm::DenseSet<const Expr *> EmittedFinals;
    emitAlignedClause(*this, S);
    bool HasLinears = EmitOMPLinearClauseInit(S);
    // Emit helper vars inits.

    std::pair<LValue, LValue> Bounds = CodeGenLoopBounds(*this, S);
    LValue LB = Bounds.first;
    LValue UB = Bounds.second;
    LValue ST =
        EmitOMPHelperVar(*this, cast<DeclRefExpr>(S.getStrideVariable()));
    LValue IL =
        EmitOMPHelperVar(*this, cast<DeclRefExpr>(S.getIsLastIterVariable()));

    // Emit 'then' code.
    {
      OMPPrivateScope LoopScope(*this);
      if (EmitOMPFirstprivateClause(S, LoopScope) || HasLinears) {
        // Emit implicit barrier to synchronize threads and avoid data races on
        // initialization of firstprivate variables and post-update of
        // lastprivate variables.
        CGM.getOpenMPRuntime().emitBarrierCall(
            *this, S.getBeginLoc(), OMPD_unknown, /*EmitChecks=*/false,
            /*ForceSimpleCall=*/true);
      }
      EmitOMPPrivateClause(S, LoopScope);
      HasLastprivateClause = EmitOMPLastprivateClauseInit(S, LoopScope);
      EmitOMPReductionClauseInit(S, LoopScope);
      EmitOMPPrivateLoopCounters(S, LoopScope);
      EmitOMPLinearClause(S, LoopScope);
      (void)LoopScope.Privatize();
      if (isOpenMPTargetExecutionDirective(S.getDirectiveKind()))
        CGM.getOpenMPRuntime().adjustTargetSpecificDataForLambdas(*this, S);

      // Detect the loop schedule kind and chunk.
      const Expr *ChunkExpr = nullptr;
      OpenMPScheduleTy ScheduleKind;
      if (const auto *C = S.getSingleClause<OMPScheduleClause>()) {
        ScheduleKind.Schedule = C->getScheduleKind();
        ScheduleKind.M1 = C->getFirstScheduleModifier();
        ScheduleKind.M2 = C->getSecondScheduleModifier();
        ChunkExpr = C->getChunkSize();
      } else {
        // Default behaviour for schedule clause.
        CGM.getOpenMPRuntime().getDefaultScheduleAndChunk(
            *this, S, ScheduleKind.Schedule, ChunkExpr);
      }
      bool HasChunkSizeOne = false;
      llvm::Value *Chunk = nullptr;
      if (ChunkExpr) {
        Chunk = EmitScalarExpr(ChunkExpr);
        Chunk = EmitScalarConversion(Chunk, ChunkExpr->getType(),
                                     S.getIterationVariable()->getType(),
                                     S.getBeginLoc());
        Expr::EvalResult Result;
        if (ChunkExpr->EvaluateAsInt(Result, getContext())) {
          llvm::APSInt EvaluatedChunk = Result.Val.getInt();
          HasChunkSizeOne = (EvaluatedChunk.getLimitedValue() == 1);
        }
      }
      const unsigned IVSize = getContext().getTypeSize(IVExpr->getType());
      const bool IVSigned = IVExpr->getType()->hasSignedIntegerRepresentation();
      // OpenMP 4.5, 2.7.1 Loop Construct, Description.
      // If the static schedule kind is specified or if the ordered clause is
      // specified, and if no monotonic modifier is specified, the effect will
      // be as if the monotonic modifier was specified.
      bool StaticChunkedOne = RT.isStaticChunked(ScheduleKind.Schedule,
          /* Chunked */ Chunk != nullptr) && HasChunkSizeOne &&
          isOpenMPLoopBoundSharingDirective(S.getDirectiveKind());
      if ((RT.isStaticNonchunked(ScheduleKind.Schedule,
                                 /* Chunked */ Chunk != nullptr) ||
           StaticChunkedOne) &&
          !Ordered) {
        JumpDest LoopExit =
            getJumpDestInCurrentScope(createBasicBlock("omp.loop.exit"));
        emitCommonSimdLoop(
            *this, S,
            [&S](CodeGenFunction &CGF, PrePostActionTy &) {
              if (isOpenMPSimdDirective(S.getDirectiveKind()))
                CGF.EmitOMPSimdInit(S, /*IsMonotonic=*/true);
            },
            [IVSize, IVSigned, Ordered, IL, LB, UB, ST, StaticChunkedOne, Chunk,
             &S, ScheduleKind, LoopExit,
             &LoopScope](CodeGenFunction &CGF, PrePostActionTy &) {
              // OpenMP [2.7.1, Loop Construct, Description, table 2-1]
              // When no chunk_size is specified, the iteration space is divided
              // into chunks that are approximately equal in size, and at most
              // one chunk is distributed to each thread. Note that the size of
              // the chunks is unspecified in this case.
              CGOpenMPRuntime::StaticRTInput StaticInit(
                  IVSize, IVSigned, Ordered, IL.getAddress(CGF),
                  LB.getAddress(CGF), UB.getAddress(CGF), ST.getAddress(CGF),
                  StaticChunkedOne ? Chunk : nullptr);
              CGF.CGM.getOpenMPRuntime().emitForStaticInit(
                  CGF, S.getBeginLoc(), S.getDirectiveKind(), ScheduleKind,
                  StaticInit);
              // UB = min(UB, GlobalUB);
              if (!StaticChunkedOne)
                CGF.EmitIgnoredExpr(S.getEnsureUpperBound());
              // IV = LB;
              CGF.EmitIgnoredExpr(S.getInit());
              // For unchunked static schedule generate:
              //
              // while (idx <= UB) {
              //   BODY;
              //   ++idx;
              // }
              //
              // For static schedule with chunk one:
              //
              // while (IV <= PrevUB) {
              //   BODY;
              //   IV += ST;
              // }
              CGF.EmitOMPInnerLoop(
                  S, LoopScope.requiresCleanups(),
                  StaticChunkedOne ? S.getCombinedParForInDistCond()
                                   : S.getCond(),
                  StaticChunkedOne ? S.getDistInc() : S.getInc(),
                  [&S, LoopExit](CodeGenFunction &CGF) {
                    CGF.EmitOMPLoopBody(S, LoopExit);
                    CGF.EmitStopPoint(&S);
                  },
                  [](CodeGenFunction &) {});
            });
        EmitBlock(LoopExit.getBlock());
        // Tell the runtime we are done.
        auto &&CodeGen = [&S](CodeGenFunction &CGF) {
          CGF.CGM.getOpenMPRuntime().emitForStaticFinish(CGF, S.getEndLoc(),
                                                         S.getDirectiveKind());
        };
        OMPCancelStack.emitExit(*this, S.getDirectiveKind(), CodeGen);
      } else {
        const bool IsMonotonic =
            Ordered || ScheduleKind.Schedule == OMPC_SCHEDULE_static ||
            ScheduleKind.Schedule == OMPC_SCHEDULE_unknown ||
            ScheduleKind.M1 == OMPC_SCHEDULE_MODIFIER_monotonic ||
            ScheduleKind.M2 == OMPC_SCHEDULE_MODIFIER_monotonic;
        // Emit the outer loop, which requests its work chunk [LB..UB] from
        // runtime and runs the inner loop to process it.
        const OMPLoopArguments LoopArguments(
            LB.getAddress(*this), UB.getAddress(*this), ST.getAddress(*this),
            IL.getAddress(*this), Chunk, EUB);
        EmitOMPForOuterLoop(ScheduleKind, IsMonotonic, S, LoopScope, Ordered,
                            LoopArguments, CGDispatchBounds);
      }
      if (isOpenMPSimdDirective(S.getDirectiveKind())) {
        EmitOMPSimdFinal(S, [IL, &S](CodeGenFunction &CGF) {
          return CGF.Builder.CreateIsNotNull(
              CGF.EmitLoadOfScalar(IL, S.getBeginLoc()));
        });
      }
      EmitOMPReductionClauseFinal(
          S, /*ReductionKind=*/isOpenMPSimdDirective(S.getDirectiveKind())
                 ? /*Parallel and Simd*/ OMPD_parallel_for_simd
                 : /*Parallel only*/ OMPD_parallel);
      // Emit post-update of the reduction variables if IsLastIter != 0.
      emitPostUpdateForReductionClause(
          *this, S, [IL, &S](CodeGenFunction &CGF) {
            return CGF.Builder.CreateIsNotNull(
                CGF.EmitLoadOfScalar(IL, S.getBeginLoc()));
          });
      // Emit final copy of the lastprivate variables if IsLastIter != 0.
      if (HasLastprivateClause)
        EmitOMPLastprivateClauseFinal(
            S, isOpenMPSimdDirective(S.getDirectiveKind()),
            Builder.CreateIsNotNull(EmitLoadOfScalar(IL, S.getBeginLoc())));
    }
    EmitOMPLinearClauseFinal(S, [IL, &S](CodeGenFunction &CGF) {
      return CGF.Builder.CreateIsNotNull(
          CGF.EmitLoadOfScalar(IL, S.getBeginLoc()));
    });
    DoacrossCleanupScope.ForceCleanup();
    // We're now done with the loop, so jump to the continuation block.
    if (ContBlock) {
      EmitBranch(ContBlock);
      EmitBlock(ContBlock, /*IsFinished=*/true);
    }
  }
  return HasLastprivateClause;
}

/// The following two functions generate expressions for the loop lower
/// and upper bounds in case of static and dynamic (dispatch) schedule
/// of the associated 'for' or 'distribute' loop.
static std::pair<LValue, LValue>
emitForLoopBounds(CodeGenFunction &CGF, const OMPExecutableDirective &S) {
  const auto &LS = cast<OMPLoopDirective>(S);
  LValue LB =
      EmitOMPHelperVar(CGF, cast<DeclRefExpr>(LS.getLowerBoundVariable()));
  LValue UB =
      EmitOMPHelperVar(CGF, cast<DeclRefExpr>(LS.getUpperBoundVariable()));
  return {LB, UB};
}

/// When dealing with dispatch schedules (e.g. dynamic, guided) we do not
/// consider the lower and upper bound expressions generated by the
/// worksharing loop support, but we use 0 and the iteration space size as
/// constants
static std::pair<llvm::Value *, llvm::Value *>
emitDispatchForLoopBounds(CodeGenFunction &CGF, const OMPExecutableDirective &S,
                          Address LB, Address UB) {
  const auto &LS = cast<OMPLoopDirective>(S);
  const Expr *IVExpr = LS.getIterationVariable();
  const unsigned IVSize = CGF.getContext().getTypeSize(IVExpr->getType());
  llvm::Value *LBVal = CGF.Builder.getIntN(IVSize, 0);
  llvm::Value *UBVal = CGF.EmitScalarExpr(LS.getLastIteration());
  return {LBVal, UBVal};
}

void CodeGenFunction::EmitOMPForDirective(const OMPForDirective &S) {
  bool HasLastprivates = false;
  auto &&CodeGen = [&S, &HasLastprivates](CodeGenFunction &CGF,
                                          PrePostActionTy &) {
    OMPCancelStackRAII CancelRegion(CGF, OMPD_for, S.hasCancel());
    HasLastprivates = CGF.EmitOMPWorksharingLoop(S, S.getEnsureUpperBound(),
                                                 emitForLoopBounds,
                                                 emitDispatchForLoopBounds);
  };
  {
    OMPLexicalScope Scope(*this, S, OMPD_unknown);
    CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_for, CodeGen,
                                                S.hasCancel());
  }

  // Emit an implicit barrier at the end.
  if (!S.getSingleClause<OMPNowaitClause>() || HasLastprivates)
    CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getBeginLoc(), OMPD_for);
}

void CodeGenFunction::EmitOMPForSimdDirective(const OMPForSimdDirective &S) {
  bool HasLastprivates = false;
  auto &&CodeGen = [&S, &HasLastprivates](CodeGenFunction &CGF,
                                          PrePostActionTy &) {
    HasLastprivates = CGF.EmitOMPWorksharingLoop(S, S.getEnsureUpperBound(),
                                                 emitForLoopBounds,
                                                 emitDispatchForLoopBounds);
  };
  {
    OMPLexicalScope Scope(*this, S, OMPD_unknown);
    CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_simd, CodeGen);
  }

  // Emit an implicit barrier at the end.
  if (!S.getSingleClause<OMPNowaitClause>() || HasLastprivates)
    CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getBeginLoc(), OMPD_for);
}

static LValue createSectionLVal(CodeGenFunction &CGF, QualType Ty,
                                const Twine &Name,
                                llvm::Value *Init = nullptr) {
  LValue LVal = CGF.MakeAddrLValue(CGF.CreateMemTemp(Ty, Name), Ty);
  if (Init)
    CGF.EmitStoreThroughLValue(RValue::get(Init), LVal, /*isInit*/ true);
  return LVal;
}

void CodeGenFunction::EmitSections(const OMPExecutableDirective &S) {
  const Stmt *CapturedStmt = S.getInnermostCapturedStmt()->getCapturedStmt();
  const auto *CS = dyn_cast<CompoundStmt>(CapturedStmt);
  bool HasLastprivates = false;
  auto &&CodeGen = [&S, CapturedStmt, CS,
                    &HasLastprivates](CodeGenFunction &CGF, PrePostActionTy &) {
    ASTContext &C = CGF.getContext();
    QualType KmpInt32Ty =
        C.getIntTypeForBitwidth(/*DestWidth=*/32, /*Signed=*/1);
    // Emit helper vars inits.
    LValue LB = createSectionLVal(CGF, KmpInt32Ty, ".omp.sections.lb.",
                                  CGF.Builder.getInt32(0));
    llvm::ConstantInt *GlobalUBVal = CS != nullptr
                                         ? CGF.Builder.getInt32(CS->size() - 1)
                                         : CGF.Builder.getInt32(0);
    LValue UB =
        createSectionLVal(CGF, KmpInt32Ty, ".omp.sections.ub.", GlobalUBVal);
    LValue ST = createSectionLVal(CGF, KmpInt32Ty, ".omp.sections.st.",
                                  CGF.Builder.getInt32(1));
    LValue IL = createSectionLVal(CGF, KmpInt32Ty, ".omp.sections.il.",
                                  CGF.Builder.getInt32(0));
    // Loop counter.
    LValue IV = createSectionLVal(CGF, KmpInt32Ty, ".omp.sections.iv.");
    OpaqueValueExpr IVRefExpr(S.getBeginLoc(), KmpInt32Ty, VK_LValue);
    CodeGenFunction::OpaqueValueMapping OpaqueIV(CGF, &IVRefExpr, IV);
    OpaqueValueExpr UBRefExpr(S.getBeginLoc(), KmpInt32Ty, VK_LValue);
    CodeGenFunction::OpaqueValueMapping OpaqueUB(CGF, &UBRefExpr, UB);
    // Generate condition for loop.
    BinaryOperator Cond(&IVRefExpr, &UBRefExpr, BO_LE, C.BoolTy, VK_RValue,
                        OK_Ordinary, S.getBeginLoc(), FPOptions());
    // Increment for loop counter.
    UnaryOperator Inc(&IVRefExpr, UO_PreInc, KmpInt32Ty, VK_RValue, OK_Ordinary,
                      S.getBeginLoc(), true);
    auto &&BodyGen = [CapturedStmt, CS, &S, &IV](CodeGenFunction &CGF) {
      // Iterate through all sections and emit a switch construct:
      // switch (IV) {
      //   case 0:
      //     <SectionStmt[0]>;
      //     break;
      // ...
      //   case <NumSection> - 1:
      //     <SectionStmt[<NumSection> - 1]>;
      //     break;
      // }
      // .omp.sections.exit:
      llvm::BasicBlock *ExitBB = CGF.createBasicBlock(".omp.sections.exit");
      llvm::SwitchInst *SwitchStmt =
          CGF.Builder.CreateSwitch(CGF.EmitLoadOfScalar(IV, S.getBeginLoc()),
                                   ExitBB, CS == nullptr ? 1 : CS->size());
      if (CS) {
        unsigned CaseNumber = 0;
        for (const Stmt *SubStmt : CS->children()) {
          auto CaseBB = CGF.createBasicBlock(".omp.sections.case");
          CGF.EmitBlock(CaseBB);
          SwitchStmt->addCase(CGF.Builder.getInt32(CaseNumber), CaseBB);
          CGF.EmitStmt(SubStmt);
          CGF.EmitBranch(ExitBB);
          ++CaseNumber;
        }
      } else {
        llvm::BasicBlock *CaseBB = CGF.createBasicBlock(".omp.sections.case");
        CGF.EmitBlock(CaseBB);
        SwitchStmt->addCase(CGF.Builder.getInt32(0), CaseBB);
        CGF.EmitStmt(CapturedStmt);
        CGF.EmitBranch(ExitBB);
      }
      CGF.EmitBlock(ExitBB, /*IsFinished=*/true);
    };

    CodeGenFunction::OMPPrivateScope LoopScope(CGF);
    if (CGF.EmitOMPFirstprivateClause(S, LoopScope)) {
      // Emit implicit barrier to synchronize threads and avoid data races on
      // initialization of firstprivate variables and post-update of lastprivate
      // variables.
      CGF.CGM.getOpenMPRuntime().emitBarrierCall(
          CGF, S.getBeginLoc(), OMPD_unknown, /*EmitChecks=*/false,
          /*ForceSimpleCall=*/true);
    }
    CGF.EmitOMPPrivateClause(S, LoopScope);
    HasLastprivates = CGF.EmitOMPLastprivateClauseInit(S, LoopScope);
    CGF.EmitOMPReductionClauseInit(S, LoopScope);
    (void)LoopScope.Privatize();
    if (isOpenMPTargetExecutionDirective(S.getDirectiveKind()))
      CGF.CGM.getOpenMPRuntime().adjustTargetSpecificDataForLambdas(CGF, S);

    // Emit static non-chunked loop.
    OpenMPScheduleTy ScheduleKind;
    ScheduleKind.Schedule = OMPC_SCHEDULE_static;
    CGOpenMPRuntime::StaticRTInput StaticInit(
        /*IVSize=*/32, /*IVSigned=*/true, /*Ordered=*/false, IL.getAddress(CGF),
        LB.getAddress(CGF), UB.getAddress(CGF), ST.getAddress(CGF));
    CGF.CGM.getOpenMPRuntime().emitForStaticInit(
        CGF, S.getBeginLoc(), S.getDirectiveKind(), ScheduleKind, StaticInit);
    // UB = min(UB, GlobalUB);
    llvm::Value *UBVal = CGF.EmitLoadOfScalar(UB, S.getBeginLoc());
    llvm::Value *MinUBGlobalUB = CGF.Builder.CreateSelect(
        CGF.Builder.CreateICmpSLT(UBVal, GlobalUBVal), UBVal, GlobalUBVal);
    CGF.EmitStoreOfScalar(MinUBGlobalUB, UB);
    // IV = LB;
    CGF.EmitStoreOfScalar(CGF.EmitLoadOfScalar(LB, S.getBeginLoc()), IV);
    // while (idx <= UB) { BODY; ++idx; }
    CGF.EmitOMPInnerLoop(S, /*RequiresCleanup=*/false, &Cond, &Inc, BodyGen,
                         [](CodeGenFunction &) {});
    // Tell the runtime we are done.
    auto &&CodeGen = [&S](CodeGenFunction &CGF) {
      CGF.CGM.getOpenMPRuntime().emitForStaticFinish(CGF, S.getEndLoc(),
                                                     S.getDirectiveKind());
    };
    CGF.OMPCancelStack.emitExit(CGF, S.getDirectiveKind(), CodeGen);
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_parallel);
    // Emit post-update of the reduction variables if IsLastIter != 0.
    emitPostUpdateForReductionClause(CGF, S, [IL, &S](CodeGenFunction &CGF) {
      return CGF.Builder.CreateIsNotNull(
          CGF.EmitLoadOfScalar(IL, S.getBeginLoc()));
    });

    // Emit final copy of the lastprivate variables if IsLastIter != 0.
    if (HasLastprivates)
      CGF.EmitOMPLastprivateClauseFinal(
          S, /*NoFinals=*/false,
          CGF.Builder.CreateIsNotNull(
              CGF.EmitLoadOfScalar(IL, S.getBeginLoc())));
  };

  bool HasCancel = false;
  if (auto *OSD = dyn_cast<OMPSectionsDirective>(&S))
    HasCancel = OSD->hasCancel();
  else if (auto *OPSD = dyn_cast<OMPParallelSectionsDirective>(&S))
    HasCancel = OPSD->hasCancel();
  OMPCancelStackRAII CancelRegion(*this, S.getDirectiveKind(), HasCancel);
  CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_sections, CodeGen,
                                              HasCancel);
  // Emit barrier for lastprivates only if 'sections' directive has 'nowait'
  // clause. Otherwise the barrier will be generated by the codegen for the
  // directive.
  if (HasLastprivates && S.getSingleClause<OMPNowaitClause>()) {
    // Emit implicit barrier to synchronize threads and avoid data races on
    // initialization of firstprivate variables.
    CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getBeginLoc(),
                                           OMPD_unknown);
  }
}

void CodeGenFunction::EmitOMPSectionsDirective(const OMPSectionsDirective &S) {
  {
    OMPLexicalScope Scope(*this, S, OMPD_unknown);
    EmitSections(S);
  }
  // Emit an implicit barrier at the end.
  if (!S.getSingleClause<OMPNowaitClause>()) {
    CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getBeginLoc(),
                                           OMPD_sections);
  }
}

void CodeGenFunction::EmitOMPSectionDirective(const OMPSectionDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitStmt(S.getInnermostCapturedStmt()->getCapturedStmt());
  };
  OMPLexicalScope Scope(*this, S, OMPD_unknown);
  CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_section, CodeGen,
                                              S.hasCancel());
}

void CodeGenFunction::EmitOMPSingleDirective(const OMPSingleDirective &S) {
  llvm::SmallVector<const Expr *, 8> CopyprivateVars;
  llvm::SmallVector<const Expr *, 8> DestExprs;
  llvm::SmallVector<const Expr *, 8> SrcExprs;
  llvm::SmallVector<const Expr *, 8> AssignmentOps;
  // Check if there are any 'copyprivate' clauses associated with this
  // 'single' construct.
  // Build a list of copyprivate variables along with helper expressions
  // (<source>, <destination>, <destination>=<source> expressions)
  for (const auto *C : S.getClausesOfKind<OMPCopyprivateClause>()) {
    CopyprivateVars.append(C->varlists().begin(), C->varlists().end());
    DestExprs.append(C->destination_exprs().begin(),
                     C->destination_exprs().end());
    SrcExprs.append(C->source_exprs().begin(), C->source_exprs().end());
    AssignmentOps.append(C->assignment_ops().begin(),
                         C->assignment_ops().end());
  }
  // Emit code for 'single' region along with 'copyprivate' clauses
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    OMPPrivateScope SingleScope(CGF);
    (void)CGF.EmitOMPFirstprivateClause(S, SingleScope);
    CGF.EmitOMPPrivateClause(S, SingleScope);
    (void)SingleScope.Privatize();
    CGF.EmitStmt(S.getInnermostCapturedStmt()->getCapturedStmt());
  };
  {
    OMPLexicalScope Scope(*this, S, OMPD_unknown);
    CGM.getOpenMPRuntime().emitSingleRegion(*this, CodeGen, S.getBeginLoc(),
                                            CopyprivateVars, DestExprs,
                                            SrcExprs, AssignmentOps);
  }
  // Emit an implicit barrier at the end (to avoid data race on firstprivate
  // init or if no 'nowait' clause was specified and no 'copyprivate' clause).
  if (!S.getSingleClause<OMPNowaitClause>() && CopyprivateVars.empty()) {
    CGM.getOpenMPRuntime().emitBarrierCall(
        *this, S.getBeginLoc(),
        S.getSingleClause<OMPNowaitClause>() ? OMPD_unknown : OMPD_single);
  }
}

static void emitMaster(CodeGenFunction &CGF, const OMPExecutableDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    CGF.EmitStmt(S.getInnermostCapturedStmt()->getCapturedStmt());
  };
  CGF.CGM.getOpenMPRuntime().emitMasterRegion(CGF, CodeGen, S.getBeginLoc());
}

void CodeGenFunction::EmitOMPMasterDirective(const OMPMasterDirective &S) {
  OMPLexicalScope Scope(*this, S, OMPD_unknown);
  emitMaster(*this, S);
}

void CodeGenFunction::EmitOMPCriticalDirective(const OMPCriticalDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    CGF.EmitStmt(S.getInnermostCapturedStmt()->getCapturedStmt());
  };
  const Expr *Hint = nullptr;
  if (const auto *HintClause = S.getSingleClause<OMPHintClause>())
    Hint = HintClause->getHint();
  OMPLexicalScope Scope(*this, S, OMPD_unknown);
  CGM.getOpenMPRuntime().emitCriticalRegion(*this,
                                            S.getDirectiveName().getAsString(),
                                            CodeGen, S.getBeginLoc(), Hint);
}

void CodeGenFunction::EmitOMPParallelForDirective(
    const OMPParallelForDirective &S) {
  // Emit directive as a combined directive that consists of two implicit
  // directives: 'parallel' with 'for' directive.
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    OMPCancelStackRAII CancelRegion(CGF, OMPD_parallel_for, S.hasCancel());
    CGF.EmitOMPWorksharingLoop(S, S.getEnsureUpperBound(), emitForLoopBounds,
                               emitDispatchForLoopBounds);
  };
  emitCommonOMPParallelDirective(*this, S, OMPD_for, CodeGen,
                                 emitEmptyBoundParameters);
}

void CodeGenFunction::EmitOMPParallelForSimdDirective(
    const OMPParallelForSimdDirective &S) {
  // Emit directive as a combined directive that consists of two implicit
  // directives: 'parallel' with 'for' directive.
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    CGF.EmitOMPWorksharingLoop(S, S.getEnsureUpperBound(), emitForLoopBounds,
                               emitDispatchForLoopBounds);
  };
  emitCommonOMPParallelDirective(*this, S, OMPD_simd, CodeGen,
                                 emitEmptyBoundParameters);
}

void CodeGenFunction::EmitOMPParallelMasterDirective(
    const OMPParallelMasterDirective &S) {
  // Emit directive as a combined directive that consists of two implicit
  // directives: 'parallel' with 'master' directive.
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    OMPPrivateScope PrivateScope(CGF);
    bool Copyins = CGF.EmitOMPCopyinClause(S);
    (void)CGF.EmitOMPFirstprivateClause(S, PrivateScope);
    if (Copyins) {
      // Emit implicit barrier to synchronize threads and avoid data races on
      // propagation master's thread values of threadprivate variables to local
      // instances of that variables of all other implicit threads.
      CGF.CGM.getOpenMPRuntime().emitBarrierCall(
          CGF, S.getBeginLoc(), OMPD_unknown, /*EmitChecks=*/false,
          /*ForceSimpleCall=*/true);
    }
    CGF.EmitOMPPrivateClause(S, PrivateScope);
    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
    (void)PrivateScope.Privatize();
    emitMaster(CGF, S);
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_parallel);
  };
  emitCommonOMPParallelDirective(*this, S, OMPD_master, CodeGen,
                                 emitEmptyBoundParameters);
  emitPostUpdateForReductionClause(*this, S,
                                   [](CodeGenFunction &) { return nullptr; });
}

void CodeGenFunction::EmitOMPParallelSectionsDirective(
    const OMPParallelSectionsDirective &S) {
  // Emit directive as a combined directive that consists of two implicit
  // directives: 'parallel' with 'sections' directive.
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    CGF.EmitSections(S);
  };
  emitCommonOMPParallelDirective(*this, S, OMPD_sections, CodeGen,
                                 emitEmptyBoundParameters);
}

void CodeGenFunction::EmitOMPTaskBasedDirective(
    const OMPExecutableDirective &S, const OpenMPDirectiveKind CapturedRegion,
    const RegionCodeGenTy &BodyGen, const TaskGenTy &TaskGen,
    OMPTaskDataTy &Data) {
  // Emit outlined function for task construct.
  const CapturedStmt *CS = S.getCapturedStmt(CapturedRegion);
  auto I = CS->getCapturedDecl()->param_begin();
  auto PartId = std::next(I);
  auto TaskT = std::next(I, 4);
  // Check if the task is final
  if (const auto *Clause = S.getSingleClause<OMPFinalClause>()) {
    // If the condition constant folds and can be elided, try to avoid emitting
    // the condition and the dead arm of the if/else.
    const Expr *Cond = Clause->getCondition();
    bool CondConstant;
    if (ConstantFoldsToSimpleInteger(Cond, CondConstant))
      Data.Final.setInt(CondConstant);
    else
      Data.Final.setPointer(EvaluateExprAsBool(Cond));
  } else {
    // By default the task is not final.
    Data.Final.setInt(/*IntVal=*/false);
  }
  // Check if the task has 'priority' clause.
  if (const auto *Clause = S.getSingleClause<OMPPriorityClause>()) {
    const Expr *Prio = Clause->getPriority();
    Data.Priority.setInt(/*IntVal=*/true);
    Data.Priority.setPointer(EmitScalarConversion(
        EmitScalarExpr(Prio), Prio->getType(),
        getContext().getIntTypeForBitwidth(/*DestWidth=*/32, /*Signed=*/1),
        Prio->getExprLoc()));
  }
  // The first function argument for tasks is a thread id, the second one is a
  // part id (0 for tied tasks, >=0 for untied task).
  llvm::DenseSet<const VarDecl *> EmittedAsPrivate;
  // Get list of private variables.
  for (const auto *C : S.getClausesOfKind<OMPPrivateClause>()) {
    auto IRef = C->varlist_begin();
    for (const Expr *IInit : C->private_copies()) {
      const auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
      if (EmittedAsPrivate.insert(OrigVD->getCanonicalDecl()).second) {
        Data.PrivateVars.push_back(*IRef);
        Data.PrivateCopies.push_back(IInit);
      }
      ++IRef;
    }
  }
  EmittedAsPrivate.clear();
  // Get list of firstprivate variables.
  for (const auto *C : S.getClausesOfKind<OMPFirstprivateClause>()) {
    auto IRef = C->varlist_begin();
    auto IElemInitRef = C->inits().begin();
    for (const Expr *IInit : C->private_copies()) {
      const auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
      if (EmittedAsPrivate.insert(OrigVD->getCanonicalDecl()).second) {
        Data.FirstprivateVars.push_back(*IRef);
        Data.FirstprivateCopies.push_back(IInit);
        Data.FirstprivateInits.push_back(*IElemInitRef);
      }
      ++IRef;
      ++IElemInitRef;
    }
  }
  // Get list of lastprivate variables (for taskloops).
  llvm::DenseMap<const VarDecl *, const DeclRefExpr *> LastprivateDstsOrigs;
  for (const auto *C : S.getClausesOfKind<OMPLastprivateClause>()) {
    auto IRef = C->varlist_begin();
    auto ID = C->destination_exprs().begin();
    for (const Expr *IInit : C->private_copies()) {
      const auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
      if (EmittedAsPrivate.insert(OrigVD->getCanonicalDecl()).second) {
        Data.LastprivateVars.push_back(*IRef);
        Data.LastprivateCopies.push_back(IInit);
      }
      LastprivateDstsOrigs.insert(
          {cast<VarDecl>(cast<DeclRefExpr>(*ID)->getDecl()),
           cast<DeclRefExpr>(*IRef)});
      ++IRef;
      ++ID;
    }
  }
  SmallVector<const Expr *, 4> LHSs;
  SmallVector<const Expr *, 4> RHSs;
  for (const auto *C : S.getClausesOfKind<OMPReductionClause>()) {
    auto IPriv = C->privates().begin();
    auto IRed = C->reduction_ops().begin();
    auto ILHS = C->lhs_exprs().begin();
    auto IRHS = C->rhs_exprs().begin();
    for (const Expr *Ref : C->varlists()) {
      Data.ReductionVars.emplace_back(Ref);
      Data.ReductionCopies.emplace_back(*IPriv);
      Data.ReductionOps.emplace_back(*IRed);
      LHSs.emplace_back(*ILHS);
      RHSs.emplace_back(*IRHS);
      std::advance(IPriv, 1);
      std::advance(IRed, 1);
      std::advance(ILHS, 1);
      std::advance(IRHS, 1);
    }
  }
  Data.Reductions = CGM.getOpenMPRuntime().emitTaskReductionInit(
      *this, S.getBeginLoc(), LHSs, RHSs, Data);
  // Build list of dependences.
  for (const auto *C : S.getClausesOfKind<OMPDependClause>())
    for (const Expr *IRef : C->varlists())
      Data.Dependences.emplace_back(C->getDependencyKind(), IRef);
  auto &&CodeGen = [&Data, &S, CS, &BodyGen, &LastprivateDstsOrigs,
                    CapturedRegion](CodeGenFunction &CGF,
                                    PrePostActionTy &Action) {
    // Set proper addresses for generated private copies.
    OMPPrivateScope Scope(CGF);
    if (!Data.PrivateVars.empty() || !Data.FirstprivateVars.empty() ||
        !Data.LastprivateVars.empty()) {
      llvm::FunctionType *CopyFnTy = llvm::FunctionType::get(
          CGF.Builder.getVoidTy(), {CGF.Builder.getInt8PtrTy()}, true);
      enum { PrivatesParam = 2, CopyFnParam = 3 };
      llvm::Value *CopyFn = CGF.Builder.CreateLoad(
          CGF.GetAddrOfLocalVar(CS->getCapturedDecl()->getParam(CopyFnParam)));
      llvm::Value *PrivatesPtr = CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(
          CS->getCapturedDecl()->getParam(PrivatesParam)));
      // Map privates.
      llvm::SmallVector<std::pair<const VarDecl *, Address>, 16> PrivatePtrs;
      llvm::SmallVector<llvm::Value *, 16> CallArgs;
      CallArgs.push_back(PrivatesPtr);
      for (const Expr *E : Data.PrivateVars) {
        const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
        Address PrivatePtr = CGF.CreateMemTemp(
            CGF.getContext().getPointerType(E->getType()), ".priv.ptr.addr");
        PrivatePtrs.emplace_back(VD, PrivatePtr);
        CallArgs.push_back(PrivatePtr.getPointer());
      }
      for (const Expr *E : Data.FirstprivateVars) {
        const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
        Address PrivatePtr =
            CGF.CreateMemTemp(CGF.getContext().getPointerType(E->getType()),
                              ".firstpriv.ptr.addr");
        PrivatePtrs.emplace_back(VD, PrivatePtr);
        CallArgs.push_back(PrivatePtr.getPointer());
      }
      for (const Expr *E : Data.LastprivateVars) {
        const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
        Address PrivatePtr =
            CGF.CreateMemTemp(CGF.getContext().getPointerType(E->getType()),
                              ".lastpriv.ptr.addr");
        PrivatePtrs.emplace_back(VD, PrivatePtr);
        CallArgs.push_back(PrivatePtr.getPointer());
      }
      CGF.CGM.getOpenMPRuntime().emitOutlinedFunctionCall(
          CGF, S.getBeginLoc(), {CopyFnTy, CopyFn}, CallArgs);
      for (const auto &Pair : LastprivateDstsOrigs) {
        const auto *OrigVD = cast<VarDecl>(Pair.second->getDecl());
        DeclRefExpr DRE(CGF.getContext(), const_cast<VarDecl *>(OrigVD),
                        /*RefersToEnclosingVariableOrCapture=*/
                            CGF.CapturedStmtInfo->lookup(OrigVD) != nullptr,
                        Pair.second->getType(), VK_LValue,
                        Pair.second->getExprLoc());
        Scope.addPrivate(Pair.first, [&CGF, &DRE]() {
          return CGF.EmitLValue(&DRE).getAddress(CGF);
        });
      }
      for (const auto &Pair : PrivatePtrs) {
        Address Replacement(CGF.Builder.CreateLoad(Pair.second),
                            CGF.getContext().getDeclAlign(Pair.first));
        Scope.addPrivate(Pair.first, [Replacement]() { return Replacement; });
      }
    }
    if (Data.Reductions) {
      OMPLexicalScope LexScope(CGF, S, CapturedRegion);
      ReductionCodeGen RedCG(Data.ReductionVars, Data.ReductionCopies,
                             Data.ReductionOps);
      llvm::Value *ReductionsPtr = CGF.Builder.CreateLoad(
          CGF.GetAddrOfLocalVar(CS->getCapturedDecl()->getParam(9)));
      for (unsigned Cnt = 0, E = Data.ReductionVars.size(); Cnt < E; ++Cnt) {
        RedCG.emitSharedLValue(CGF, Cnt);
        RedCG.emitAggregateType(CGF, Cnt);
        // FIXME: This must removed once the runtime library is fixed.
        // Emit required threadprivate variables for
        // initializer/combiner/finalizer.
        CGF.CGM.getOpenMPRuntime().emitTaskReductionFixups(CGF, S.getBeginLoc(),
                                                           RedCG, Cnt);
        Address Replacement = CGF.CGM.getOpenMPRuntime().getTaskReductionItem(
            CGF, S.getBeginLoc(), ReductionsPtr, RedCG.getSharedLValue(Cnt));
        Replacement =
            Address(CGF.EmitScalarConversion(
                        Replacement.getPointer(), CGF.getContext().VoidPtrTy,
                        CGF.getContext().getPointerType(
                            Data.ReductionCopies[Cnt]->getType()),
                        Data.ReductionCopies[Cnt]->getExprLoc()),
                    Replacement.getAlignment());
        Replacement = RedCG.adjustPrivateAddress(CGF, Cnt, Replacement);
        Scope.addPrivate(RedCG.getBaseDecl(Cnt),
                         [Replacement]() { return Replacement; });
      }
    }
    // Privatize all private variables except for in_reduction items.
    (void)Scope.Privatize();
    SmallVector<const Expr *, 4> InRedVars;
    SmallVector<const Expr *, 4> InRedPrivs;
    SmallVector<const Expr *, 4> InRedOps;
    SmallVector<const Expr *, 4> TaskgroupDescriptors;
    for (const auto *C : S.getClausesOfKind<OMPInReductionClause>()) {
      auto IPriv = C->privates().begin();
      auto IRed = C->reduction_ops().begin();
      auto ITD = C->taskgroup_descriptors().begin();
      for (const Expr *Ref : C->varlists()) {
        InRedVars.emplace_back(Ref);
        InRedPrivs.emplace_back(*IPriv);
        InRedOps.emplace_back(*IRed);
        TaskgroupDescriptors.emplace_back(*ITD);
        std::advance(IPriv, 1);
        std::advance(IRed, 1);
        std::advance(ITD, 1);
      }
    }
    // Privatize in_reduction items here, because taskgroup descriptors must be
    // privatized earlier.
    OMPPrivateScope InRedScope(CGF);
    if (!InRedVars.empty()) {
      ReductionCodeGen RedCG(InRedVars, InRedPrivs, InRedOps);
      for (unsigned Cnt = 0, E = InRedVars.size(); Cnt < E; ++Cnt) {
        RedCG.emitSharedLValue(CGF, Cnt);
        RedCG.emitAggregateType(CGF, Cnt);
        // The taskgroup descriptor variable is always implicit firstprivate and
        // privatized already during processing of the firstprivates.
        // FIXME: This must removed once the runtime library is fixed.
        // Emit required threadprivate variables for
        // initializer/combiner/finalizer.
        CGF.CGM.getOpenMPRuntime().emitTaskReductionFixups(CGF, S.getBeginLoc(),
                                                           RedCG, Cnt);
        llvm::Value *ReductionsPtr =
            CGF.EmitLoadOfScalar(CGF.EmitLValue(TaskgroupDescriptors[Cnt]),
                                 TaskgroupDescriptors[Cnt]->getExprLoc());
        Address Replacement = CGF.CGM.getOpenMPRuntime().getTaskReductionItem(
            CGF, S.getBeginLoc(), ReductionsPtr, RedCG.getSharedLValue(Cnt));
        Replacement = Address(
            CGF.EmitScalarConversion(
                Replacement.getPointer(), CGF.getContext().VoidPtrTy,
                CGF.getContext().getPointerType(InRedPrivs[Cnt]->getType()),
                InRedPrivs[Cnt]->getExprLoc()),
            Replacement.getAlignment());
        Replacement = RedCG.adjustPrivateAddress(CGF, Cnt, Replacement);
        InRedScope.addPrivate(RedCG.getBaseDecl(Cnt),
                              [Replacement]() { return Replacement; });
      }
    }
    (void)InRedScope.Privatize();

    Action.Enter(CGF);
    BodyGen(CGF);
  };
  llvm::Function *OutlinedFn = CGM.getOpenMPRuntime().emitTaskOutlinedFunction(
      S, *I, *PartId, *TaskT, S.getDirectiveKind(), CodeGen, Data.Tied,
      Data.NumberOfParts);
  OMPLexicalScope Scope(*this, S, llvm::None,
                        !isOpenMPParallelDirective(S.getDirectiveKind()) &&
                            !isOpenMPSimdDirective(S.getDirectiveKind()));
  TaskGen(*this, OutlinedFn, Data);
}

static ImplicitParamDecl *
createImplicitFirstprivateForType(ASTContext &C, OMPTaskDataTy &Data,
                                  QualType Ty, CapturedDecl *CD,
                                  SourceLocation Loc) {
  auto *OrigVD = ImplicitParamDecl::Create(C, CD, Loc, /*Id=*/nullptr, Ty,
                                           ImplicitParamDecl::Other);
  auto *OrigRef = DeclRefExpr::Create(
      C, NestedNameSpecifierLoc(), SourceLocation(), OrigVD,
      /*RefersToEnclosingVariableOrCapture=*/false, Loc, Ty, VK_LValue);
  auto *PrivateVD = ImplicitParamDecl::Create(C, CD, Loc, /*Id=*/nullptr, Ty,
                                              ImplicitParamDecl::Other);
  auto *PrivateRef = DeclRefExpr::Create(
      C, NestedNameSpecifierLoc(), SourceLocation(), PrivateVD,
      /*RefersToEnclosingVariableOrCapture=*/false, Loc, Ty, VK_LValue);
  QualType ElemType = C.getBaseElementType(Ty);
  auto *InitVD = ImplicitParamDecl::Create(C, CD, Loc, /*Id=*/nullptr, ElemType,
                                           ImplicitParamDecl::Other);
  auto *InitRef = DeclRefExpr::Create(
      C, NestedNameSpecifierLoc(), SourceLocation(), InitVD,
      /*RefersToEnclosingVariableOrCapture=*/false, Loc, ElemType, VK_LValue);
  PrivateVD->setInitStyle(VarDecl::CInit);
  PrivateVD->setInit(ImplicitCastExpr::Create(C, ElemType, CK_LValueToRValue,
                                              InitRef, /*BasePath=*/nullptr,
                                              VK_RValue));
  Data.FirstprivateVars.emplace_back(OrigRef);
  Data.FirstprivateCopies.emplace_back(PrivateRef);
  Data.FirstprivateInits.emplace_back(InitRef);
  return OrigVD;
}

void CodeGenFunction::EmitOMPTargetTaskBasedDirective(
    const OMPExecutableDirective &S, const RegionCodeGenTy &BodyGen,
    OMPTargetDataInfo &InputInfo) {
  // Emit outlined function for task construct.
  const CapturedStmt *CS = S.getCapturedStmt(OMPD_task);
  Address CapturedStruct = GenerateCapturedStmtArgument(*CS);
  QualType SharedsTy = getContext().getRecordType(CS->getCapturedRecordDecl());
  auto I = CS->getCapturedDecl()->param_begin();
  auto PartId = std::next(I);
  auto TaskT = std::next(I, 4);
  OMPTaskDataTy Data;
  // The task is not final.
  Data.Final.setInt(/*IntVal=*/false);
  // Get list of firstprivate variables.
  for (const auto *C : S.getClausesOfKind<OMPFirstprivateClause>()) {
    auto IRef = C->varlist_begin();
    auto IElemInitRef = C->inits().begin();
    for (auto *IInit : C->private_copies()) {
      Data.FirstprivateVars.push_back(*IRef);
      Data.FirstprivateCopies.push_back(IInit);
      Data.FirstprivateInits.push_back(*IElemInitRef);
      ++IRef;
      ++IElemInitRef;
    }
  }
  OMPPrivateScope TargetScope(*this);
  VarDecl *BPVD = nullptr;
  VarDecl *PVD = nullptr;
  VarDecl *SVD = nullptr;
  if (InputInfo.NumberOfTargetItems > 0) {
    auto *CD = CapturedDecl::Create(
        getContext(), getContext().getTranslationUnitDecl(), /*NumParams=*/0);
    llvm::APInt ArrSize(/*numBits=*/32, InputInfo.NumberOfTargetItems);
    QualType BaseAndPointersType = getContext().getConstantArrayType(
        getContext().VoidPtrTy, ArrSize, nullptr, ArrayType::Normal,
        /*IndexTypeQuals=*/0);
    BPVD = createImplicitFirstprivateForType(
        getContext(), Data, BaseAndPointersType, CD, S.getBeginLoc());
    PVD = createImplicitFirstprivateForType(
        getContext(), Data, BaseAndPointersType, CD, S.getBeginLoc());
    QualType SizesType = getContext().getConstantArrayType(
        getContext().getIntTypeForBitwidth(/*DestWidth=*/64, /*Signed=*/1),
        ArrSize, nullptr, ArrayType::Normal,
        /*IndexTypeQuals=*/0);
    SVD = createImplicitFirstprivateForType(getContext(), Data, SizesType, CD,
                                            S.getBeginLoc());
    TargetScope.addPrivate(
        BPVD, [&InputInfo]() { return InputInfo.BasePointersArray; });
    TargetScope.addPrivate(PVD,
                           [&InputInfo]() { return InputInfo.PointersArray; });
    TargetScope.addPrivate(SVD,
                           [&InputInfo]() { return InputInfo.SizesArray; });
  }
  (void)TargetScope.Privatize();
  // Build list of dependences.
  for (const auto *C : S.getClausesOfKind<OMPDependClause>())
    for (const Expr *IRef : C->varlists())
      Data.Dependences.emplace_back(C->getDependencyKind(), IRef);
  auto &&CodeGen = [&Data, &S, CS, &BodyGen, BPVD, PVD, SVD,
                    &InputInfo](CodeGenFunction &CGF, PrePostActionTy &Action) {
    // Set proper addresses for generated private copies.
    OMPPrivateScope Scope(CGF);
    if (!Data.FirstprivateVars.empty()) {
      llvm::FunctionType *CopyFnTy = llvm::FunctionType::get(
          CGF.Builder.getVoidTy(), {CGF.Builder.getInt8PtrTy()}, true);
      enum { PrivatesParam = 2, CopyFnParam = 3 };
      llvm::Value *CopyFn = CGF.Builder.CreateLoad(
          CGF.GetAddrOfLocalVar(CS->getCapturedDecl()->getParam(CopyFnParam)));
      llvm::Value *PrivatesPtr = CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(
          CS->getCapturedDecl()->getParam(PrivatesParam)));
      // Map privates.
      llvm::SmallVector<std::pair<const VarDecl *, Address>, 16> PrivatePtrs;
      llvm::SmallVector<llvm::Value *, 16> CallArgs;
      CallArgs.push_back(PrivatesPtr);
      for (const Expr *E : Data.FirstprivateVars) {
        const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
        Address PrivatePtr =
            CGF.CreateMemTemp(CGF.getContext().getPointerType(E->getType()),
                              ".firstpriv.ptr.addr");
        PrivatePtrs.emplace_back(VD, PrivatePtr);
        CallArgs.push_back(PrivatePtr.getPointer());
      }
      CGF.CGM.getOpenMPRuntime().emitOutlinedFunctionCall(
          CGF, S.getBeginLoc(), {CopyFnTy, CopyFn}, CallArgs);
      for (const auto &Pair : PrivatePtrs) {
        Address Replacement(CGF.Builder.CreateLoad(Pair.second),
                            CGF.getContext().getDeclAlign(Pair.first));
        Scope.addPrivate(Pair.first, [Replacement]() { return Replacement; });
      }
    }
    // Privatize all private variables except for in_reduction items.
    (void)Scope.Privatize();
    if (InputInfo.NumberOfTargetItems > 0) {
      InputInfo.BasePointersArray = CGF.Builder.CreateConstArrayGEP(
          CGF.GetAddrOfLocalVar(BPVD), /*Index=*/0);
      InputInfo.PointersArray = CGF.Builder.CreateConstArrayGEP(
          CGF.GetAddrOfLocalVar(PVD), /*Index=*/0);
      InputInfo.SizesArray = CGF.Builder.CreateConstArrayGEP(
          CGF.GetAddrOfLocalVar(SVD), /*Index=*/0);
    }

    Action.Enter(CGF);
    OMPLexicalScope LexScope(CGF, S, OMPD_task, /*EmitPreInitStmt=*/false);
    BodyGen(CGF);
  };
  llvm::Function *OutlinedFn = CGM.getOpenMPRuntime().emitTaskOutlinedFunction(
      S, *I, *PartId, *TaskT, S.getDirectiveKind(), CodeGen, /*Tied=*/true,
      Data.NumberOfParts);
  llvm::APInt TrueOrFalse(32, S.hasClausesOfKind<OMPNowaitClause>() ? 1 : 0);
  IntegerLiteral IfCond(getContext(), TrueOrFalse,
                        getContext().getIntTypeForBitwidth(32, /*Signed=*/0),
                        SourceLocation());

  CGM.getOpenMPRuntime().emitTaskCall(*this, S.getBeginLoc(), S, OutlinedFn,
                                      SharedsTy, CapturedStruct, &IfCond, Data);
}

void CodeGenFunction::EmitOMPTaskDirective(const OMPTaskDirective &S) {
  // Emit outlined function for task construct.
  const CapturedStmt *CS = S.getCapturedStmt(OMPD_task);
  Address CapturedStruct = GenerateCapturedStmtArgument(*CS);
  QualType SharedsTy = getContext().getRecordType(CS->getCapturedRecordDecl());
  const Expr *IfCond = nullptr;
  for (const auto *C : S.getClausesOfKind<OMPIfClause>()) {
    if (C->getNameModifier() == OMPD_unknown ||
        C->getNameModifier() == OMPD_task) {
      IfCond = C->getCondition();
      break;
    }
  }

  OMPTaskDataTy Data;
  // Check if we should emit tied or untied task.
  Data.Tied = !S.getSingleClause<OMPUntiedClause>();
  auto &&BodyGen = [CS](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitStmt(CS->getCapturedStmt());
  };
  auto &&TaskGen = [&S, SharedsTy, CapturedStruct,
                    IfCond](CodeGenFunction &CGF, llvm::Function *OutlinedFn,
                            const OMPTaskDataTy &Data) {
    CGF.CGM.getOpenMPRuntime().emitTaskCall(CGF, S.getBeginLoc(), S, OutlinedFn,
                                            SharedsTy, CapturedStruct, IfCond,
                                            Data);
  };
  EmitOMPTaskBasedDirective(S, OMPD_task, BodyGen, TaskGen, Data);
}

void CodeGenFunction::EmitOMPTaskyieldDirective(
    const OMPTaskyieldDirective &S) {
  CGM.getOpenMPRuntime().emitTaskyieldCall(*this, S.getBeginLoc());
}

void CodeGenFunction::EmitOMPBarrierDirective(const OMPBarrierDirective &S) {
  CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getBeginLoc(), OMPD_barrier);
}

void CodeGenFunction::EmitOMPTaskwaitDirective(const OMPTaskwaitDirective &S) {
  CGM.getOpenMPRuntime().emitTaskwaitCall(*this, S.getBeginLoc());
}

void CodeGenFunction::EmitOMPTaskgroupDirective(
    const OMPTaskgroupDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    if (const Expr *E = S.getReductionRef()) {
      SmallVector<const Expr *, 4> LHSs;
      SmallVector<const Expr *, 4> RHSs;
      OMPTaskDataTy Data;
      for (const auto *C : S.getClausesOfKind<OMPTaskReductionClause>()) {
        auto IPriv = C->privates().begin();
        auto IRed = C->reduction_ops().begin();
        auto ILHS = C->lhs_exprs().begin();
        auto IRHS = C->rhs_exprs().begin();
        for (const Expr *Ref : C->varlists()) {
          Data.ReductionVars.emplace_back(Ref);
          Data.ReductionCopies.emplace_back(*IPriv);
          Data.ReductionOps.emplace_back(*IRed);
          LHSs.emplace_back(*ILHS);
          RHSs.emplace_back(*IRHS);
          std::advance(IPriv, 1);
          std::advance(IRed, 1);
          std::advance(ILHS, 1);
          std::advance(IRHS, 1);
        }
      }
      llvm::Value *ReductionDesc =
          CGF.CGM.getOpenMPRuntime().emitTaskReductionInit(CGF, S.getBeginLoc(),
                                                           LHSs, RHSs, Data);
      const auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
      CGF.EmitVarDecl(*VD);
      CGF.EmitStoreOfScalar(ReductionDesc, CGF.GetAddrOfLocalVar(VD),
                            /*Volatile=*/false, E->getType());
    }
    CGF.EmitStmt(S.getInnermostCapturedStmt()->getCapturedStmt());
  };
  OMPLexicalScope Scope(*this, S, OMPD_unknown);
  CGM.getOpenMPRuntime().emitTaskgroupRegion(*this, CodeGen, S.getBeginLoc());
}

void CodeGenFunction::EmitOMPFlushDirective(const OMPFlushDirective &S) {
  CGM.getOpenMPRuntime().emitFlush(
      *this,
      [&S]() -> ArrayRef<const Expr *> {
        if (const auto *FlushClause = S.getSingleClause<OMPFlushClause>())
          return llvm::makeArrayRef(FlushClause->varlist_begin(),
                                    FlushClause->varlist_end());
        return llvm::None;
      }(),
      S.getBeginLoc());
}

void CodeGenFunction::EmitOMPDistributeLoop(const OMPLoopDirective &S,
                                            const CodeGenLoopTy &CodeGenLoop,
                                            Expr *IncExpr) {
  // Emit the loop iteration variable.
  const auto *IVExpr = cast<DeclRefExpr>(S.getIterationVariable());
  const auto *IVDecl = cast<VarDecl>(IVExpr->getDecl());
  EmitVarDecl(*IVDecl);

  // Emit the iterations count variable.
  // If it is not a variable, Sema decided to calculate iterations count on each
  // iteration (e.g., it is foldable into a constant).
  if (const auto *LIExpr = dyn_cast<DeclRefExpr>(S.getLastIteration())) {
    EmitVarDecl(*cast<VarDecl>(LIExpr->getDecl()));
    // Emit calculation of the iterations count.
    EmitIgnoredExpr(S.getCalcLastIteration());
  }

  CGOpenMPRuntime &RT = CGM.getOpenMPRuntime();

  bool HasLastprivateClause = false;
  // Check pre-condition.
  {
    OMPLoopScope PreInitScope(*this, S);
    // Skip the entire loop if we don't meet the precondition.
    // If the condition constant folds and can be elided, avoid emitting the
    // whole loop.
    bool CondConstant;
    llvm::BasicBlock *ContBlock = nullptr;
    if (ConstantFoldsToSimpleInteger(S.getPreCond(), CondConstant)) {
      if (!CondConstant)
        return;
    } else {
      llvm::BasicBlock *ThenBlock = createBasicBlock("omp.precond.then");
      ContBlock = createBasicBlock("omp.precond.end");
      emitPreCond(*this, S, S.getPreCond(), ThenBlock, ContBlock,
                  getProfileCount(&S));
      EmitBlock(ThenBlock);
      incrementProfileCounter(&S);
    }

    emitAlignedClause(*this, S);
    // Emit 'then' code.
    {
      // Emit helper vars inits.

      LValue LB = EmitOMPHelperVar(
          *this, cast<DeclRefExpr>(
                     (isOpenMPLoopBoundSharingDirective(S.getDirectiveKind())
                          ? S.getCombinedLowerBoundVariable()
                          : S.getLowerBoundVariable())));
      LValue UB = EmitOMPHelperVar(
          *this, cast<DeclRefExpr>(
                     (isOpenMPLoopBoundSharingDirective(S.getDirectiveKind())
                          ? S.getCombinedUpperBoundVariable()
                          : S.getUpperBoundVariable())));
      LValue ST =
          EmitOMPHelperVar(*this, cast<DeclRefExpr>(S.getStrideVariable()));
      LValue IL =
          EmitOMPHelperVar(*this, cast<DeclRefExpr>(S.getIsLastIterVariable()));

      OMPPrivateScope LoopScope(*this);
      if (EmitOMPFirstprivateClause(S, LoopScope)) {
        // Emit implicit barrier to synchronize threads and avoid data races
        // on initialization of firstprivate variables and post-update of
        // lastprivate variables.
        CGM.getOpenMPRuntime().emitBarrierCall(
            *this, S.getBeginLoc(), OMPD_unknown, /*EmitChecks=*/false,
            /*ForceSimpleCall=*/true);
      }
      EmitOMPPrivateClause(S, LoopScope);
      if (isOpenMPSimdDirective(S.getDirectiveKind()) &&
          !isOpenMPParallelDirective(S.getDirectiveKind()) &&
          !isOpenMPTeamsDirective(S.getDirectiveKind()))
        EmitOMPReductionClauseInit(S, LoopScope);
      HasLastprivateClause = EmitOMPLastprivateClauseInit(S, LoopScope);
      EmitOMPPrivateLoopCounters(S, LoopScope);
      (void)LoopScope.Privatize();
      if (isOpenMPTargetExecutionDirective(S.getDirectiveKind()))
        CGM.getOpenMPRuntime().adjustTargetSpecificDataForLambdas(*this, S);

      // Detect the distribute schedule kind and chunk.
      llvm::Value *Chunk = nullptr;
      OpenMPDistScheduleClauseKind ScheduleKind = OMPC_DIST_SCHEDULE_unknown;
      if (const auto *C = S.getSingleClause<OMPDistScheduleClause>()) {
        ScheduleKind = C->getDistScheduleKind();
        if (const Expr *Ch = C->getChunkSize()) {
          Chunk = EmitScalarExpr(Ch);
          Chunk = EmitScalarConversion(Chunk, Ch->getType(),
                                       S.getIterationVariable()->getType(),
                                       S.getBeginLoc());
        }
      } else {
        // Default behaviour for dist_schedule clause.
        CGM.getOpenMPRuntime().getDefaultDistScheduleAndChunk(
            *this, S, ScheduleKind, Chunk);
      }
      const unsigned IVSize = getContext().getTypeSize(IVExpr->getType());
      const bool IVSigned = IVExpr->getType()->hasSignedIntegerRepresentation();

      // OpenMP [2.10.8, distribute Construct, Description]
      // If dist_schedule is specified, kind must be static. If specified,
      // iterations are divided into chunks of size chunk_size, chunks are
      // assigned to the teams of the league in a round-robin fashion in the
      // order of the team number. When no chunk_size is specified, the
      // iteration space is divided into chunks that are approximately equal
      // in size, and at most one chunk is distributed to each team of the
      // league. The size of the chunks is unspecified in this case.
      bool StaticChunked = RT.isStaticChunked(
          ScheduleKind, /* Chunked */ Chunk != nullptr) &&
          isOpenMPLoopBoundSharingDirective(S.getDirectiveKind());
      if (RT.isStaticNonchunked(ScheduleKind,
                                /* Chunked */ Chunk != nullptr) ||
          StaticChunked) {
        if (isOpenMPSimdDirective(S.getDirectiveKind()))
          EmitOMPSimdInit(S, /*IsMonotonic=*/true);
        CGOpenMPRuntime::StaticRTInput StaticInit(
            IVSize, IVSigned, /* Ordered = */ false, IL.getAddress(*this),
            LB.getAddress(*this), UB.getAddress(*this), ST.getAddress(*this),
            StaticChunked ? Chunk : nullptr);
        RT.emitDistributeStaticInit(*this, S.getBeginLoc(), ScheduleKind,
                                    StaticInit);
        JumpDest LoopExit =
            getJumpDestInCurrentScope(createBasicBlock("omp.loop.exit"));
        // UB = min(UB, GlobalUB);
        EmitIgnoredExpr(isOpenMPLoopBoundSharingDirective(S.getDirectiveKind())
                            ? S.getCombinedEnsureUpperBound()
                            : S.getEnsureUpperBound());
        // IV = LB;
        EmitIgnoredExpr(isOpenMPLoopBoundSharingDirective(S.getDirectiveKind())
                            ? S.getCombinedInit()
                            : S.getInit());

        const Expr *Cond =
            isOpenMPLoopBoundSharingDirective(S.getDirectiveKind())
                ? S.getCombinedCond()
                : S.getCond();

        if (StaticChunked)
          Cond = S.getCombinedDistCond();

        // For static unchunked schedules generate:
        //
        //  1. For distribute alone, codegen
        //    while (idx <= UB) {
        //      BODY;
        //      ++idx;
        //    }
        //
        //  2. When combined with 'for' (e.g. as in 'distribute parallel for')
        //    while (idx <= UB) {
        //      <CodeGen rest of pragma>(LB, UB);
        //      idx += ST;
        //    }
        //
        // For static chunk one schedule generate:
        //
        // while (IV <= GlobalUB) {
        //   <CodeGen rest of pragma>(LB, UB);
        //   LB += ST;
        //   UB += ST;
        //   UB = min(UB, GlobalUB);
        //   IV = LB;
        // }
        //
        EmitOMPInnerLoop(S, LoopScope.requiresCleanups(), Cond, IncExpr,
                         [&S, LoopExit, &CodeGenLoop](CodeGenFunction &CGF) {
                           CodeGenLoop(CGF, S, LoopExit);
                         },
                         [&S, StaticChunked](CodeGenFunction &CGF) {
                           if (StaticChunked) {
                             CGF.EmitIgnoredExpr(S.getCombinedNextLowerBound());
                             CGF.EmitIgnoredExpr(S.getCombinedNextUpperBound());
                             CGF.EmitIgnoredExpr(S.getCombinedEnsureUpperBound());
                             CGF.EmitIgnoredExpr(S.getCombinedInit());
                           }
                         });
        EmitBlock(LoopExit.getBlock());
        // Tell the runtime we are done.
        RT.emitForStaticFinish(*this, S.getBeginLoc(), S.getDirectiveKind());
      } else {
        // Emit the outer loop, which requests its work chunk [LB..UB] from
        // runtime and runs the inner loop to process it.
        const OMPLoopArguments LoopArguments = {
            LB.getAddress(*this), UB.getAddress(*this), ST.getAddress(*this),
            IL.getAddress(*this), Chunk};
        EmitOMPDistributeOuterLoop(ScheduleKind, S, LoopScope, LoopArguments,
                                   CodeGenLoop);
      }
      if (isOpenMPSimdDirective(S.getDirectiveKind())) {
        EmitOMPSimdFinal(S, [IL, &S](CodeGenFunction &CGF) {
          return CGF.Builder.CreateIsNotNull(
              CGF.EmitLoadOfScalar(IL, S.getBeginLoc()));
        });
      }
      if (isOpenMPSimdDirective(S.getDirectiveKind()) &&
          !isOpenMPParallelDirective(S.getDirectiveKind()) &&
          !isOpenMPTeamsDirective(S.getDirectiveKind())) {
        EmitOMPReductionClauseFinal(S, OMPD_simd);
        // Emit post-update of the reduction variables if IsLastIter != 0.
        emitPostUpdateForReductionClause(
            *this, S, [IL, &S](CodeGenFunction &CGF) {
              return CGF.Builder.CreateIsNotNull(
                  CGF.EmitLoadOfScalar(IL, S.getBeginLoc()));
            });
      }
      // Emit final copy of the lastprivate variables if IsLastIter != 0.
      if (HasLastprivateClause) {
        EmitOMPLastprivateClauseFinal(
            S, /*NoFinals=*/false,
            Builder.CreateIsNotNull(EmitLoadOfScalar(IL, S.getBeginLoc())));
      }
    }

    // We're now done with the loop, so jump to the continuation block.
    if (ContBlock) {
      EmitBranch(ContBlock);
      EmitBlock(ContBlock, true);
    }
  }
}

void CodeGenFunction::EmitOMPDistributeDirective(
    const OMPDistributeDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitOMPDistributeLoop(S, emitOMPLoopBodyWithStopPoint, S.getInc());
  };
  OMPLexicalScope Scope(*this, S, OMPD_unknown);
  CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_distribute, CodeGen);
}

static llvm::Function *emitOutlinedOrderedFunction(CodeGenModule &CGM,
                                                   const CapturedStmt *S) {
  CodeGenFunction CGF(CGM, /*suppressNewContext=*/true);
  CodeGenFunction::CGCapturedStmtInfo CapStmtInfo;
  CGF.CapturedStmtInfo = &CapStmtInfo;
  llvm::Function *Fn = CGF.GenerateOpenMPCapturedStmtFunction(*S);
  Fn->setDoesNotRecurse();
  return Fn;
}

void CodeGenFunction::EmitOMPOrderedDirective(const OMPOrderedDirective &S) {
  if (S.hasClausesOfKind<OMPDependClause>()) {
    assert(!S.getAssociatedStmt() &&
           "No associated statement must be in ordered depend construct.");
    for (const auto *DC : S.getClausesOfKind<OMPDependClause>())
      CGM.getOpenMPRuntime().emitDoacrossOrdered(*this, DC);
    return;
  }
  const auto *C = S.getSingleClause<OMPSIMDClause>();
  auto &&CodeGen = [&S, C, this](CodeGenFunction &CGF,
                                 PrePostActionTy &Action) {
    const CapturedStmt *CS = S.getInnermostCapturedStmt();
    if (C) {
      llvm::SmallVector<llvm::Value *, 16> CapturedVars;
      CGF.GenerateOpenMPCapturedVars(*CS, CapturedVars);
      llvm::Function *OutlinedFn = emitOutlinedOrderedFunction(CGM, CS);
      CGM.getOpenMPRuntime().emitOutlinedFunctionCall(CGF, S.getBeginLoc(),
                                                      OutlinedFn, CapturedVars);
    } else {
      Action.Enter(CGF);
      CGF.EmitStmt(CS->getCapturedStmt());
    }
  };
  OMPLexicalScope Scope(*this, S, OMPD_unknown);
  CGM.getOpenMPRuntime().emitOrderedRegion(*this, CodeGen, S.getBeginLoc(), !C);
}

static llvm::Value *convertToScalarValue(CodeGenFunction &CGF, RValue Val,
                                         QualType SrcType, QualType DestType,
                                         SourceLocation Loc) {
  assert(CGF.hasScalarEvaluationKind(DestType) &&
         "DestType must have scalar evaluation kind.");
  assert(!Val.isAggregate() && "Must be a scalar or complex.");
  return Val.isScalar() ? CGF.EmitScalarConversion(Val.getScalarVal(), SrcType,
                                                   DestType, Loc)
                        : CGF.EmitComplexToScalarConversion(
                              Val.getComplexVal(), SrcType, DestType, Loc);
}

static CodeGenFunction::ComplexPairTy
convertToComplexValue(CodeGenFunction &CGF, RValue Val, QualType SrcType,
                      QualType DestType, SourceLocation Loc) {
  assert(CGF.getEvaluationKind(DestType) == TEK_Complex &&
         "DestType must have complex evaluation kind.");
  CodeGenFunction::ComplexPairTy ComplexVal;
  if (Val.isScalar()) {
    // Convert the input element to the element type of the complex.
    QualType DestElementType =
        DestType->castAs<ComplexType>()->getElementType();
    llvm::Value *ScalarVal = CGF.EmitScalarConversion(
        Val.getScalarVal(), SrcType, DestElementType, Loc);
    ComplexVal = CodeGenFunction::ComplexPairTy(
        ScalarVal, llvm::Constant::getNullValue(ScalarVal->getType()));
  } else {
    assert(Val.isComplex() && "Must be a scalar or complex.");
    QualType SrcElementType = SrcType->castAs<ComplexType>()->getElementType();
    QualType DestElementType =
        DestType->castAs<ComplexType>()->getElementType();
    ComplexVal.first = CGF.EmitScalarConversion(
        Val.getComplexVal().first, SrcElementType, DestElementType, Loc);
    ComplexVal.second = CGF.EmitScalarConversion(
        Val.getComplexVal().second, SrcElementType, DestElementType, Loc);
  }
  return ComplexVal;
}

static void emitSimpleAtomicStore(CodeGenFunction &CGF, bool IsSeqCst,
                                  LValue LVal, RValue RVal) {
  if (LVal.isGlobalReg()) {
    CGF.EmitStoreThroughGlobalRegLValue(RVal, LVal);
  } else {
    CGF.EmitAtomicStore(RVal, LVal,
                        IsSeqCst ? llvm::AtomicOrdering::SequentiallyConsistent
                                 : llvm::AtomicOrdering::Monotonic,
                        LVal.isVolatile(), /*isInit=*/false);
  }
}

void CodeGenFunction::emitOMPSimpleStore(LValue LVal, RValue RVal,
                                         QualType RValTy, SourceLocation Loc) {
  switch (getEvaluationKind(LVal.getType())) {
  case TEK_Scalar:
    EmitStoreThroughLValue(RValue::get(convertToScalarValue(
                               *this, RVal, RValTy, LVal.getType(), Loc)),
                           LVal);
    break;
  case TEK_Complex:
    EmitStoreOfComplex(
        convertToComplexValue(*this, RVal, RValTy, LVal.getType(), Loc), LVal,
        /*isInit=*/false);
    break;
  case TEK_Aggregate:
    llvm_unreachable("Must be a scalar or complex.");
  }
}

static void emitOMPAtomicReadExpr(CodeGenFunction &CGF, bool IsSeqCst,
                                  const Expr *X, const Expr *V,
                                  SourceLocation Loc) {
  // v = x;
  assert(V->isLValue() && "V of 'omp atomic read' is not lvalue");
  assert(X->isLValue() && "X of 'omp atomic read' is not lvalue");
  LValue XLValue = CGF.EmitLValue(X);
  LValue VLValue = CGF.EmitLValue(V);
  RValue Res = XLValue.isGlobalReg()
                   ? CGF.EmitLoadOfLValue(XLValue, Loc)
                   : CGF.EmitAtomicLoad(
                         XLValue, Loc,
                         IsSeqCst ? llvm::AtomicOrdering::SequentiallyConsistent
                                  : llvm::AtomicOrdering::Monotonic,
                         XLValue.isVolatile());
  // OpenMP, 2.12.6, atomic Construct
  // Any atomic construct with a seq_cst clause forces the atomically
  // performed operation to include an implicit flush operation without a
  // list.
  if (IsSeqCst)
    CGF.CGM.getOpenMPRuntime().emitFlush(CGF, llvm::None, Loc);
  CGF.emitOMPSimpleStore(VLValue, Res, X->getType().getNonReferenceType(), Loc);
}

static void emitOMPAtomicWriteExpr(CodeGenFunction &CGF, bool IsSeqCst,
                                   const Expr *X, const Expr *E,
                                   SourceLocation Loc) {
  // x = expr;
  assert(X->isLValue() && "X of 'omp atomic write' is not lvalue");
  emitSimpleAtomicStore(CGF, IsSeqCst, CGF.EmitLValue(X), CGF.EmitAnyExpr(E));
  // OpenMP, 2.12.6, atomic Construct
  // Any atomic construct with a seq_cst clause forces the atomically
  // performed operation to include an implicit flush operation without a
  // list.
  if (IsSeqCst)
    CGF.CGM.getOpenMPRuntime().emitFlush(CGF, llvm::None, Loc);
}

static std::pair<bool, RValue> emitOMPAtomicRMW(CodeGenFunction &CGF, LValue X,
                                                RValue Update,
                                                BinaryOperatorKind BO,
                                                llvm::AtomicOrdering AO,
                                                bool IsXLHSInRHSPart) {
  ASTContext &Context = CGF.getContext();
  // Allow atomicrmw only if 'x' and 'update' are integer values, lvalue for 'x'
  // expression is simple and atomic is allowed for the given type for the
  // target platform.
  if (BO == BO_Comma || !Update.isScalar() ||
      !Update.getScalarVal()->getType()->isIntegerTy() || !X.isSimple() ||
      (!isa<llvm::ConstantInt>(Update.getScalarVal()) &&
       (Update.getScalarVal()->getType() !=
        X.getAddress(CGF).getElementType())) ||
      !X.getAddress(CGF).getElementType()->isIntegerTy() ||
      !Context.getTargetInfo().hasBuiltinAtomic(
          Context.getTypeSize(X.getType()), Context.toBits(X.getAlignment())))
    return std::make_pair(false, RValue::get(nullptr));

  llvm::AtomicRMWInst::BinOp RMWOp;
  switch (BO) {
  case BO_Add:
    RMWOp = llvm::AtomicRMWInst::Add;
    break;
  case BO_Sub:
    if (!IsXLHSInRHSPart)
      return std::make_pair(false, RValue::get(nullptr));
    RMWOp = llvm::AtomicRMWInst::Sub;
    break;
  case BO_And:
    RMWOp = llvm::AtomicRMWInst::And;
    break;
  case BO_Or:
    RMWOp = llvm::AtomicRMWInst::Or;
    break;
  case BO_Xor:
    RMWOp = llvm::AtomicRMWInst::Xor;
    break;
  case BO_LT:
    RMWOp = X.getType()->hasSignedIntegerRepresentation()
                ? (IsXLHSInRHSPart ? llvm::AtomicRMWInst::Min
                                   : llvm::AtomicRMWInst::Max)
                : (IsXLHSInRHSPart ? llvm::AtomicRMWInst::UMin
                                   : llvm::AtomicRMWInst::UMax);
    break;
  case BO_GT:
    RMWOp = X.getType()->hasSignedIntegerRepresentation()
                ? (IsXLHSInRHSPart ? llvm::AtomicRMWInst::Max
                                   : llvm::AtomicRMWInst::Min)
                : (IsXLHSInRHSPart ? llvm::AtomicRMWInst::UMax
                                   : llvm::AtomicRMWInst::UMin);
    break;
  case BO_Assign:
    RMWOp = llvm::AtomicRMWInst::Xchg;
    break;
  case BO_Mul:
  case BO_Div:
  case BO_Rem:
  case BO_Shl:
  case BO_Shr:
  case BO_LAnd:
  case BO_LOr:
    return std::make_pair(false, RValue::get(nullptr));
  case BO_PtrMemD:
  case BO_PtrMemI:
  case BO_LE:
  case BO_GE:
  case BO_EQ:
  case BO_NE:
  case BO_Cmp:
  case BO_AddAssign:
  case BO_SubAssign:
  case BO_AndAssign:
  case BO_OrAssign:
  case BO_XorAssign:
  case BO_MulAssign:
  case BO_DivAssign:
  case BO_RemAssign:
  case BO_ShlAssign:
  case BO_ShrAssign:
  case BO_Comma:
    llvm_unreachable("Unsupported atomic update operation");
  }
  llvm::Value *UpdateVal = Update.getScalarVal();
  if (auto *IC = dyn_cast<llvm::ConstantInt>(UpdateVal)) {
    UpdateVal = CGF.Builder.CreateIntCast(
        IC, X.getAddress(CGF).getElementType(),
        X.getType()->hasSignedIntegerRepresentation());
  }
  llvm::Value *Res =
      CGF.Builder.CreateAtomicRMW(RMWOp, X.getPointer(CGF), UpdateVal, AO);
  return std::make_pair(true, RValue::get(Res));
}

std::pair<bool, RValue> CodeGenFunction::EmitOMPAtomicSimpleUpdateExpr(
    LValue X, RValue E, BinaryOperatorKind BO, bool IsXLHSInRHSPart,
    llvm::AtomicOrdering AO, SourceLocation Loc,
    const llvm::function_ref<RValue(RValue)> CommonGen) {
  // Update expressions are allowed to have the following forms:
  // x binop= expr; -> xrval + expr;
  // x++, ++x -> xrval + 1;
  // x--, --x -> xrval - 1;
  // x = x binop expr; -> xrval binop expr
  // x = expr Op x; - > expr binop xrval;
  auto Res = emitOMPAtomicRMW(*this, X, E, BO, AO, IsXLHSInRHSPart);
  if (!Res.first) {
    if (X.isGlobalReg()) {
      // Emit an update expression: 'xrval' binop 'expr' or 'expr' binop
      // 'xrval'.
      EmitStoreThroughLValue(CommonGen(EmitLoadOfLValue(X, Loc)), X);
    } else {
      // Perform compare-and-swap procedure.
      EmitAtomicUpdate(X, AO, CommonGen, X.getType().isVolatileQualified());
    }
  }
  return Res;
}

static void emitOMPAtomicUpdateExpr(CodeGenFunction &CGF, bool IsSeqCst,
                                    const Expr *X, const Expr *E,
                                    const Expr *UE, bool IsXLHSInRHSPart,
                                    SourceLocation Loc) {
  assert(isa<BinaryOperator>(UE->IgnoreImpCasts()) &&
         "Update expr in 'atomic update' must be a binary operator.");
  const auto *BOUE = cast<BinaryOperator>(UE->IgnoreImpCasts());
  // Update expressions are allowed to have the following forms:
  // x binop= expr; -> xrval + expr;
  // x++, ++x -> xrval + 1;
  // x--, --x -> xrval - 1;
  // x = x binop expr; -> xrval binop expr
  // x = expr Op x; - > expr binop xrval;
  assert(X->isLValue() && "X of 'omp atomic update' is not lvalue");
  LValue XLValue = CGF.EmitLValue(X);
  RValue ExprRValue = CGF.EmitAnyExpr(E);
  llvm::AtomicOrdering AO = IsSeqCst
                                ? llvm::AtomicOrdering::SequentiallyConsistent
                                : llvm::AtomicOrdering::Monotonic;
  const auto *LHS = cast<OpaqueValueExpr>(BOUE->getLHS()->IgnoreImpCasts());
  const auto *RHS = cast<OpaqueValueExpr>(BOUE->getRHS()->IgnoreImpCasts());
  const OpaqueValueExpr *XRValExpr = IsXLHSInRHSPart ? LHS : RHS;
  const OpaqueValueExpr *ERValExpr = IsXLHSInRHSPart ? RHS : LHS;
  auto &&Gen = [&CGF, UE, ExprRValue, XRValExpr, ERValExpr](RValue XRValue) {
    CodeGenFunction::OpaqueValueMapping MapExpr(CGF, ERValExpr, ExprRValue);
    CodeGenFunction::OpaqueValueMapping MapX(CGF, XRValExpr, XRValue);
    return CGF.EmitAnyExpr(UE);
  };
  (void)CGF.EmitOMPAtomicSimpleUpdateExpr(
      XLValue, ExprRValue, BOUE->getOpcode(), IsXLHSInRHSPart, AO, Loc, Gen);
  // OpenMP, 2.12.6, atomic Construct
  // Any atomic construct with a seq_cst clause forces the atomically
  // performed operation to include an implicit flush operation without a
  // list.
  if (IsSeqCst)
    CGF.CGM.getOpenMPRuntime().emitFlush(CGF, llvm::None, Loc);
}

static RValue convertToType(CodeGenFunction &CGF, RValue Value,
                            QualType SourceType, QualType ResType,
                            SourceLocation Loc) {
  switch (CGF.getEvaluationKind(ResType)) {
  case TEK_Scalar:
    return RValue::get(
        convertToScalarValue(CGF, Value, SourceType, ResType, Loc));
  case TEK_Complex: {
    auto Res = convertToComplexValue(CGF, Value, SourceType, ResType, Loc);
    return RValue::getComplex(Res.first, Res.second);
  }
  case TEK_Aggregate:
    break;
  }
  llvm_unreachable("Must be a scalar or complex.");
}

static void emitOMPAtomicCaptureExpr(CodeGenFunction &CGF, bool IsSeqCst,
                                     bool IsPostfixUpdate, const Expr *V,
                                     const Expr *X, const Expr *E,
                                     const Expr *UE, bool IsXLHSInRHSPart,
                                     SourceLocation Loc) {
  assert(X->isLValue() && "X of 'omp atomic capture' is not lvalue");
  assert(V->isLValue() && "V of 'omp atomic capture' is not lvalue");
  RValue NewVVal;
  LValue VLValue = CGF.EmitLValue(V);
  LValue XLValue = CGF.EmitLValue(X);
  RValue ExprRValue = CGF.EmitAnyExpr(E);
  llvm::AtomicOrdering AO = IsSeqCst
                                ? llvm::AtomicOrdering::SequentiallyConsistent
                                : llvm::AtomicOrdering::Monotonic;
  QualType NewVValType;
  if (UE) {
    // 'x' is updated with some additional value.
    assert(isa<BinaryOperator>(UE->IgnoreImpCasts()) &&
           "Update expr in 'atomic capture' must be a binary operator.");
    const auto *BOUE = cast<BinaryOperator>(UE->IgnoreImpCasts());
    // Update expressions are allowed to have the following forms:
    // x binop= expr; -> xrval + expr;
    // x++, ++x -> xrval + 1;
    // x--, --x -> xrval - 1;
    // x = x binop expr; -> xrval binop expr
    // x = expr Op x; - > expr binop xrval;
    const auto *LHS = cast<OpaqueValueExpr>(BOUE->getLHS()->IgnoreImpCasts());
    const auto *RHS = cast<OpaqueValueExpr>(BOUE->getRHS()->IgnoreImpCasts());
    const OpaqueValueExpr *XRValExpr = IsXLHSInRHSPart ? LHS : RHS;
    NewVValType = XRValExpr->getType();
    const OpaqueValueExpr *ERValExpr = IsXLHSInRHSPart ? RHS : LHS;
    auto &&Gen = [&CGF, &NewVVal, UE, ExprRValue, XRValExpr, ERValExpr,
                  IsPostfixUpdate](RValue XRValue) {
      CodeGenFunction::OpaqueValueMapping MapExpr(CGF, ERValExpr, ExprRValue);
      CodeGenFunction::OpaqueValueMapping MapX(CGF, XRValExpr, XRValue);
      RValue Res = CGF.EmitAnyExpr(UE);
      NewVVal = IsPostfixUpdate ? XRValue : Res;
      return Res;
    };
    auto Res = CGF.EmitOMPAtomicSimpleUpdateExpr(
        XLValue, ExprRValue, BOUE->getOpcode(), IsXLHSInRHSPart, AO, Loc, Gen);
    if (Res.first) {
      // 'atomicrmw' instruction was generated.
      if (IsPostfixUpdate) {
        // Use old value from 'atomicrmw'.
        NewVVal = Res.second;
      } else {
        // 'atomicrmw' does not provide new value, so evaluate it using old
        // value of 'x'.
        CodeGenFunction::OpaqueValueMapping MapExpr(CGF, ERValExpr, ExprRValue);
        CodeGenFunction::OpaqueValueMapping MapX(CGF, XRValExpr, Res.second);
        NewVVal = CGF.EmitAnyExpr(UE);
      }
    }
  } else {
    // 'x' is simply rewritten with some 'expr'.
    NewVValType = X->getType().getNonReferenceType();
    ExprRValue = convertToType(CGF, ExprRValue, E->getType(),
                               X->getType().getNonReferenceType(), Loc);
    auto &&Gen = [&NewVVal, ExprRValue](RValue XRValue) {
      NewVVal = XRValue;
      return ExprRValue;
    };
    // Try to perform atomicrmw xchg, otherwise simple exchange.
    auto Res = CGF.EmitOMPAtomicSimpleUpdateExpr(
        XLValue, ExprRValue, /*BO=*/BO_Assign, /*IsXLHSInRHSPart=*/false, AO,
        Loc, Gen);
    if (Res.first) {
      // 'atomicrmw' instruction was generated.
      NewVVal = IsPostfixUpdate ? Res.second : ExprRValue;
    }
  }
  // Emit post-update store to 'v' of old/new 'x' value.
  CGF.emitOMPSimpleStore(VLValue, NewVVal, NewVValType, Loc);
  // OpenMP, 2.12.6, atomic Construct
  // Any atomic construct with a seq_cst clause forces the atomically
  // performed operation to include an implicit flush operation without a
  // list.
  if (IsSeqCst)
    CGF.CGM.getOpenMPRuntime().emitFlush(CGF, llvm::None, Loc);
}

static void emitOMPAtomicExpr(CodeGenFunction &CGF, OpenMPClauseKind Kind,
                              bool IsSeqCst, bool IsPostfixUpdate,
                              const Expr *X, const Expr *V, const Expr *E,
                              const Expr *UE, bool IsXLHSInRHSPart,
                              SourceLocation Loc) {
  switch (Kind) {
  case OMPC_read:
    emitOMPAtomicReadExpr(CGF, IsSeqCst, X, V, Loc);
    break;
  case OMPC_write:
    emitOMPAtomicWriteExpr(CGF, IsSeqCst, X, E, Loc);
    break;
  case OMPC_unknown:
  case OMPC_update:
    emitOMPAtomicUpdateExpr(CGF, IsSeqCst, X, E, UE, IsXLHSInRHSPart, Loc);
    break;
  case OMPC_capture:
    emitOMPAtomicCaptureExpr(CGF, IsSeqCst, IsPostfixUpdate, V, X, E, UE,
                             IsXLHSInRHSPart, Loc);
    break;
  case OMPC_if:
  case OMPC_final:
  case OMPC_num_threads:
  case OMPC_private:
  case OMPC_firstprivate:
  case OMPC_lastprivate:
  case OMPC_reduction:
  case OMPC_task_reduction:
  case OMPC_in_reduction:
  case OMPC_safelen:
  case OMPC_simdlen:
  case OMPC_allocator:
  case OMPC_allocate:
  case OMPC_collapse:
  case OMPC_default:
  case OMPC_seq_cst:
  case OMPC_shared:
  case OMPC_linear:
  case OMPC_aligned:
  case OMPC_copyin:
  case OMPC_copyprivate:
  case OMPC_flush:
  case OMPC_proc_bind:
  case OMPC_schedule:
  case OMPC_ordered:
  case OMPC_nowait:
  case OMPC_untied:
  case OMPC_threadprivate:
  case OMPC_depend:
  case OMPC_mergeable:
  case OMPC_device:
  case OMPC_threads:
  case OMPC_simd:
  case OMPC_map:
  case OMPC_num_teams:
  case OMPC_thread_limit:
  case OMPC_priority:
  case OMPC_grainsize:
  case OMPC_nogroup:
  case OMPC_num_tasks:
  case OMPC_hint:
  case OMPC_dist_schedule:
  case OMPC_defaultmap:
  case OMPC_uniform:
  case OMPC_to:
  case OMPC_from:
  case OMPC_use_device_ptr:
  case OMPC_is_device_ptr:
  case OMPC_unified_address:
  case OMPC_unified_shared_memory:
  case OMPC_reverse_offload:
  case OMPC_dynamic_allocators:
  case OMPC_atomic_default_mem_order:
  case OMPC_device_type:
  case OMPC_match:
    llvm_unreachable("Clause is not allowed in 'omp atomic'.");
  }
}

void CodeGenFunction::EmitOMPAtomicDirective(const OMPAtomicDirective &S) {
  bool IsSeqCst = S.getSingleClause<OMPSeqCstClause>();
  OpenMPClauseKind Kind = OMPC_unknown;
  for (const OMPClause *C : S.clauses()) {
    // Find first clause (skip seq_cst clause, if it is first).
    if (C->getClauseKind() != OMPC_seq_cst) {
      Kind = C->getClauseKind();
      break;
    }
  }

  const Stmt *CS = S.getInnermostCapturedStmt()->IgnoreContainers();
  if (const auto *FE = dyn_cast<FullExpr>(CS))
    enterFullExpression(FE);
  // Processing for statements under 'atomic capture'.
  if (const auto *Compound = dyn_cast<CompoundStmt>(CS)) {
    for (const Stmt *C : Compound->body()) {
      if (const auto *FE = dyn_cast<FullExpr>(C))
        enterFullExpression(FE);
    }
  }

  auto &&CodeGen = [&S, Kind, IsSeqCst, CS](CodeGenFunction &CGF,
                                            PrePostActionTy &) {
    CGF.EmitStopPoint(CS);
    emitOMPAtomicExpr(CGF, Kind, IsSeqCst, S.isPostfixUpdate(), S.getX(),
                      S.getV(), S.getExpr(), S.getUpdateExpr(),
                      S.isXLHSInRHSPart(), S.getBeginLoc());
  };
  OMPLexicalScope Scope(*this, S, OMPD_unknown);
  CGM.getOpenMPRuntime().emitInlinedDirective(*this, OMPD_atomic, CodeGen);
}

static void emitCommonOMPTargetDirective(CodeGenFunction &CGF,
                                         const OMPExecutableDirective &S,
                                         const RegionCodeGenTy &CodeGen) {
  assert(isOpenMPTargetExecutionDirective(S.getDirectiveKind()));
  CodeGenModule &CGM = CGF.CGM;

  // On device emit this construct as inlined code.
  if (CGM.getLangOpts().OpenMPIsDevice) {
    OMPLexicalScope Scope(CGF, S, OMPD_target);
    CGM.getOpenMPRuntime().emitInlinedDirective(
        CGF, OMPD_target, [&S](CodeGenFunction &CGF, PrePostActionTy &) {
          CGF.EmitStmt(S.getInnermostCapturedStmt()->getCapturedStmt());
        });
    return;
  }

  llvm::Function *Fn = nullptr;
  llvm::Constant *FnID = nullptr;

  const Expr *IfCond = nullptr;
  // Check for the at most one if clause associated with the target region.
  for (const auto *C : S.getClausesOfKind<OMPIfClause>()) {
    if (C->getNameModifier() == OMPD_unknown ||
        C->getNameModifier() == OMPD_target) {
      IfCond = C->getCondition();
      break;
    }
  }

  // Check if we have any device clause associated with the directive.
  const Expr *Device = nullptr;
  if (auto *C = S.getSingleClause<OMPDeviceClause>())
    Device = C->getDevice();

  // Check if we have an if clause whose conditional always evaluates to false
  // or if we do not have any targets specified. If so the target region is not
  // an offload entry point.
  bool IsOffloadEntry = true;
  if (IfCond) {
    bool Val;
    if (CGF.ConstantFoldsToSimpleInteger(IfCond, Val) && !Val)
      IsOffloadEntry = false;
  }
  if (CGM.getLangOpts().OMPTargetTriples.empty())
    IsOffloadEntry = false;

  assert(CGF.CurFuncDecl && "No parent declaration for target region!");
  StringRef ParentName;
  // In case we have Ctors/Dtors we use the complete type variant to produce
  // the mangling of the device outlined kernel.
  if (const auto *D = dyn_cast<CXXConstructorDecl>(CGF.CurFuncDecl))
    ParentName = CGM.getMangledName(GlobalDecl(D, Ctor_Complete));
  else if (const auto *D = dyn_cast<CXXDestructorDecl>(CGF.CurFuncDecl))
    ParentName = CGM.getMangledName(GlobalDecl(D, Dtor_Complete));
  else
    ParentName =
        CGM.getMangledName(GlobalDecl(cast<FunctionDecl>(CGF.CurFuncDecl)));

  // Emit target region as a standalone region.
  CGM.getOpenMPRuntime().emitTargetOutlinedFunction(S, ParentName, Fn, FnID,
                                                    IsOffloadEntry, CodeGen);
  OMPLexicalScope Scope(CGF, S, OMPD_task);
  auto &&SizeEmitter =
      [IsOffloadEntry](CodeGenFunction &CGF,
                       const OMPLoopDirective &D) -> llvm::Value * {
    if (IsOffloadEntry) {
      OMPLoopScope(CGF, D);
      // Emit calculation of the iterations count.
      llvm::Value *NumIterations = CGF.EmitScalarExpr(D.getNumIterations());
      NumIterations = CGF.Builder.CreateIntCast(NumIterations, CGF.Int64Ty,
                                                /*isSigned=*/false);
      return NumIterations;
    }
    return nullptr;
  };
  CGM.getOpenMPRuntime().emitTargetCall(CGF, S, Fn, FnID, IfCond, Device,
                                        SizeEmitter);
}

static void emitTargetRegion(CodeGenFunction &CGF, const OMPTargetDirective &S,
                             PrePostActionTy &Action) {
  Action.Enter(CGF);
  CodeGenFunction::OMPPrivateScope PrivateScope(CGF);
  (void)CGF.EmitOMPFirstprivateClause(S, PrivateScope);
  CGF.EmitOMPPrivateClause(S, PrivateScope);
  (void)PrivateScope.Privatize();
  if (isOpenMPTargetExecutionDirective(S.getDirectiveKind()))
    CGF.CGM.getOpenMPRuntime().adjustTargetSpecificDataForLambdas(CGF, S);

  CGF.EmitStmt(S.getCapturedStmt(OMPD_target)->getCapturedStmt());
}

void CodeGenFunction::EmitOMPTargetDeviceFunction(CodeGenModule &CGM,
                                                  StringRef ParentName,
                                                  const OMPTargetDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetRegion(CGF, S, Action);
  };
  llvm::Function *Fn;
  llvm::Constant *Addr;
  // Emit target region as a standalone region.
  CGM.getOpenMPRuntime().emitTargetOutlinedFunction(
      S, ParentName, Fn, Addr, /*IsOffloadEntry=*/true, CodeGen);
  assert(Fn && Addr && "Target device function emission failed.");
}

void CodeGenFunction::EmitOMPTargetDirective(const OMPTargetDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetRegion(CGF, S, Action);
  };
  emitCommonOMPTargetDirective(*this, S, CodeGen);
}

static void emitCommonOMPTeamsDirective(CodeGenFunction &CGF,
                                        const OMPExecutableDirective &S,
                                        OpenMPDirectiveKind InnermostKind,
                                        const RegionCodeGenTy &CodeGen) {
  const CapturedStmt *CS = S.getCapturedStmt(OMPD_teams);
  llvm::Function *OutlinedFn =
      CGF.CGM.getOpenMPRuntime().emitTeamsOutlinedFunction(
          S, *CS->getCapturedDecl()->param_begin(), InnermostKind, CodeGen);

  const auto *NT = S.getSingleClause<OMPNumTeamsClause>();
  const auto *TL = S.getSingleClause<OMPThreadLimitClause>();
  if (NT || TL) {
    const Expr *NumTeams = NT ? NT->getNumTeams() : nullptr;
    const Expr *ThreadLimit = TL ? TL->getThreadLimit() : nullptr;

    CGF.CGM.getOpenMPRuntime().emitNumTeamsClause(CGF, NumTeams, ThreadLimit,
                                                  S.getBeginLoc());
  }

  OMPTeamsScope Scope(CGF, S);
  llvm::SmallVector<llvm::Value *, 16> CapturedVars;
  CGF.GenerateOpenMPCapturedVars(*CS, CapturedVars);
  CGF.CGM.getOpenMPRuntime().emitTeamsCall(CGF, S, S.getBeginLoc(), OutlinedFn,
                                           CapturedVars);
}

void CodeGenFunction::EmitOMPTeamsDirective(const OMPTeamsDirective &S) {
  // Emit teams region as a standalone region.
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    OMPPrivateScope PrivateScope(CGF);
    (void)CGF.EmitOMPFirstprivateClause(S, PrivateScope);
    CGF.EmitOMPPrivateClause(S, PrivateScope);
    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
    (void)PrivateScope.Privatize();
    CGF.EmitStmt(S.getCapturedStmt(OMPD_teams)->getCapturedStmt());
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_teams);
  };
  emitCommonOMPTeamsDirective(*this, S, OMPD_distribute, CodeGen);
  emitPostUpdateForReductionClause(*this, S,
                                   [](CodeGenFunction &) { return nullptr; });
}

static void emitTargetTeamsRegion(CodeGenFunction &CGF, PrePostActionTy &Action,
                                  const OMPTargetTeamsDirective &S) {
  auto *CS = S.getCapturedStmt(OMPD_teams);
  Action.Enter(CGF);
  // Emit teams region as a standalone region.
  auto &&CodeGen = [&S, CS](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    CodeGenFunction::OMPPrivateScope PrivateScope(CGF);
    (void)CGF.EmitOMPFirstprivateClause(S, PrivateScope);
    CGF.EmitOMPPrivateClause(S, PrivateScope);
    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
    (void)PrivateScope.Privatize();
    if (isOpenMPTargetExecutionDirective(S.getDirectiveKind()))
      CGF.CGM.getOpenMPRuntime().adjustTargetSpecificDataForLambdas(CGF, S);
    CGF.EmitStmt(CS->getCapturedStmt());
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_teams);
  };
  emitCommonOMPTeamsDirective(CGF, S, OMPD_teams, CodeGen);
  emitPostUpdateForReductionClause(CGF, S,
                                   [](CodeGenFunction &) { return nullptr; });
}

void CodeGenFunction::EmitOMPTargetTeamsDeviceFunction(
    CodeGenModule &CGM, StringRef ParentName,
    const OMPTargetTeamsDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetTeamsRegion(CGF, Action, S);
  };
  llvm::Function *Fn;
  llvm::Constant *Addr;
  // Emit target region as a standalone region.
  CGM.getOpenMPRuntime().emitTargetOutlinedFunction(
      S, ParentName, Fn, Addr, /*IsOffloadEntry=*/true, CodeGen);
  assert(Fn && Addr && "Target device function emission failed.");
}

void CodeGenFunction::EmitOMPTargetTeamsDirective(
    const OMPTargetTeamsDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetTeamsRegion(CGF, Action, S);
  };
  emitCommonOMPTargetDirective(*this, S, CodeGen);
}

static void
emitTargetTeamsDistributeRegion(CodeGenFunction &CGF, PrePostActionTy &Action,
                                const OMPTargetTeamsDistributeDirective &S) {
  Action.Enter(CGF);
  auto &&CodeGenDistribute = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitOMPDistributeLoop(S, emitOMPLoopBodyWithStopPoint, S.getInc());
  };

  // Emit teams region as a standalone region.
  auto &&CodeGen = [&S, &CodeGenDistribute](CodeGenFunction &CGF,
                                            PrePostActionTy &Action) {
    Action.Enter(CGF);
    CodeGenFunction::OMPPrivateScope PrivateScope(CGF);
    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
    (void)PrivateScope.Privatize();
    CGF.CGM.getOpenMPRuntime().emitInlinedDirective(CGF, OMPD_distribute,
                                                    CodeGenDistribute);
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_teams);
  };
  emitCommonOMPTeamsDirective(CGF, S, OMPD_distribute, CodeGen);
  emitPostUpdateForReductionClause(CGF, S,
                                   [](CodeGenFunction &) { return nullptr; });
}

void CodeGenFunction::EmitOMPTargetTeamsDistributeDeviceFunction(
    CodeGenModule &CGM, StringRef ParentName,
    const OMPTargetTeamsDistributeDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetTeamsDistributeRegion(CGF, Action, S);
  };
  llvm::Function *Fn;
  llvm::Constant *Addr;
  // Emit target region as a standalone region.
  CGM.getOpenMPRuntime().emitTargetOutlinedFunction(
      S, ParentName, Fn, Addr, /*IsOffloadEntry=*/true, CodeGen);
  assert(Fn && Addr && "Target device function emission failed.");
}

void CodeGenFunction::EmitOMPTargetTeamsDistributeDirective(
    const OMPTargetTeamsDistributeDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetTeamsDistributeRegion(CGF, Action, S);
  };
  emitCommonOMPTargetDirective(*this, S, CodeGen);
}

static void emitTargetTeamsDistributeSimdRegion(
    CodeGenFunction &CGF, PrePostActionTy &Action,
    const OMPTargetTeamsDistributeSimdDirective &S) {
  Action.Enter(CGF);
  auto &&CodeGenDistribute = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitOMPDistributeLoop(S, emitOMPLoopBodyWithStopPoint, S.getInc());
  };

  // Emit teams region as a standalone region.
  auto &&CodeGen = [&S, &CodeGenDistribute](CodeGenFunction &CGF,
                                            PrePostActionTy &Action) {
    Action.Enter(CGF);
    CodeGenFunction::OMPPrivateScope PrivateScope(CGF);
    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
    (void)PrivateScope.Privatize();
    CGF.CGM.getOpenMPRuntime().emitInlinedDirective(CGF, OMPD_distribute,
                                                    CodeGenDistribute);
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_teams);
  };
  emitCommonOMPTeamsDirective(CGF, S, OMPD_distribute_simd, CodeGen);
  emitPostUpdateForReductionClause(CGF, S,
                                   [](CodeGenFunction &) { return nullptr; });
}

void CodeGenFunction::EmitOMPTargetTeamsDistributeSimdDeviceFunction(
    CodeGenModule &CGM, StringRef ParentName,
    const OMPTargetTeamsDistributeSimdDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetTeamsDistributeSimdRegion(CGF, Action, S);
  };
  llvm::Function *Fn;
  llvm::Constant *Addr;
  // Emit target region as a standalone region.
  CGM.getOpenMPRuntime().emitTargetOutlinedFunction(
      S, ParentName, Fn, Addr, /*IsOffloadEntry=*/true, CodeGen);
  assert(Fn && Addr && "Target device function emission failed.");
}

void CodeGenFunction::EmitOMPTargetTeamsDistributeSimdDirective(
    const OMPTargetTeamsDistributeSimdDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetTeamsDistributeSimdRegion(CGF, Action, S);
  };
  emitCommonOMPTargetDirective(*this, S, CodeGen);
}

void CodeGenFunction::EmitOMPTeamsDistributeDirective(
    const OMPTeamsDistributeDirective &S) {

  auto &&CodeGenDistribute = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitOMPDistributeLoop(S, emitOMPLoopBodyWithStopPoint, S.getInc());
  };

  // Emit teams region as a standalone region.
  auto &&CodeGen = [&S, &CodeGenDistribute](CodeGenFunction &CGF,
                                            PrePostActionTy &Action) {
    Action.Enter(CGF);
    OMPPrivateScope PrivateScope(CGF);
    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
    (void)PrivateScope.Privatize();
    CGF.CGM.getOpenMPRuntime().emitInlinedDirective(CGF, OMPD_distribute,
                                                    CodeGenDistribute);
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_teams);
  };
  emitCommonOMPTeamsDirective(*this, S, OMPD_distribute, CodeGen);
  emitPostUpdateForReductionClause(*this, S,
                                   [](CodeGenFunction &) { return nullptr; });
}

void CodeGenFunction::EmitOMPTeamsDistributeSimdDirective(
    const OMPTeamsDistributeSimdDirective &S) {
  auto &&CodeGenDistribute = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitOMPDistributeLoop(S, emitOMPLoopBodyWithStopPoint, S.getInc());
  };

  // Emit teams region as a standalone region.
  auto &&CodeGen = [&S, &CodeGenDistribute](CodeGenFunction &CGF,
                                            PrePostActionTy &Action) {
    Action.Enter(CGF);
    OMPPrivateScope PrivateScope(CGF);
    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
    (void)PrivateScope.Privatize();
    CGF.CGM.getOpenMPRuntime().emitInlinedDirective(CGF, OMPD_simd,
                                                    CodeGenDistribute);
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_teams);
  };
  emitCommonOMPTeamsDirective(*this, S, OMPD_distribute_simd, CodeGen);
  emitPostUpdateForReductionClause(*this, S,
                                   [](CodeGenFunction &) { return nullptr; });
}

void CodeGenFunction::EmitOMPTeamsDistributeParallelForDirective(
    const OMPTeamsDistributeParallelForDirective &S) {
  auto &&CodeGenDistribute = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitOMPDistributeLoop(S, emitInnerParallelForWhenCombined,
                              S.getDistInc());
  };

  // Emit teams region as a standalone region.
  auto &&CodeGen = [&S, &CodeGenDistribute](CodeGenFunction &CGF,
                                            PrePostActionTy &Action) {
    Action.Enter(CGF);
    OMPPrivateScope PrivateScope(CGF);
    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
    (void)PrivateScope.Privatize();
    CGF.CGM.getOpenMPRuntime().emitInlinedDirective(CGF, OMPD_distribute,
                                                    CodeGenDistribute);
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_teams);
  };
  emitCommonOMPTeamsDirective(*this, S, OMPD_distribute_parallel_for, CodeGen);
  emitPostUpdateForReductionClause(*this, S,
                                   [](CodeGenFunction &) { return nullptr; });
}

void CodeGenFunction::EmitOMPTeamsDistributeParallelForSimdDirective(
    const OMPTeamsDistributeParallelForSimdDirective &S) {
  auto &&CodeGenDistribute = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitOMPDistributeLoop(S, emitInnerParallelForWhenCombined,
                              S.getDistInc());
  };

  // Emit teams region as a standalone region.
  auto &&CodeGen = [&S, &CodeGenDistribute](CodeGenFunction &CGF,
                                            PrePostActionTy &Action) {
    Action.Enter(CGF);
    OMPPrivateScope PrivateScope(CGF);
    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
    (void)PrivateScope.Privatize();
    CGF.CGM.getOpenMPRuntime().emitInlinedDirective(
        CGF, OMPD_distribute, CodeGenDistribute, /*HasCancel=*/false);
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_teams);
  };
  emitCommonOMPTeamsDirective(*this, S, OMPD_distribute_parallel_for, CodeGen);
  emitPostUpdateForReductionClause(*this, S,
                                   [](CodeGenFunction &) { return nullptr; });
}

static void emitTargetTeamsDistributeParallelForRegion(
    CodeGenFunction &CGF, const OMPTargetTeamsDistributeParallelForDirective &S,
    PrePostActionTy &Action) {
  Action.Enter(CGF);
  auto &&CodeGenDistribute = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitOMPDistributeLoop(S, emitInnerParallelForWhenCombined,
                              S.getDistInc());
  };

  // Emit teams region as a standalone region.
  auto &&CodeGenTeams = [&S, &CodeGenDistribute](CodeGenFunction &CGF,
                                                 PrePostActionTy &Action) {
    Action.Enter(CGF);
    CodeGenFunction::OMPPrivateScope PrivateScope(CGF);
    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
    (void)PrivateScope.Privatize();
    CGF.CGM.getOpenMPRuntime().emitInlinedDirective(
        CGF, OMPD_distribute, CodeGenDistribute, /*HasCancel=*/false);
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_teams);
  };

  emitCommonOMPTeamsDirective(CGF, S, OMPD_distribute_parallel_for,
                              CodeGenTeams);
  emitPostUpdateForReductionClause(CGF, S,
                                   [](CodeGenFunction &) { return nullptr; });
}

void CodeGenFunction::EmitOMPTargetTeamsDistributeParallelForDeviceFunction(
    CodeGenModule &CGM, StringRef ParentName,
    const OMPTargetTeamsDistributeParallelForDirective &S) {
  // Emit SPMD target teams distribute parallel for region as a standalone
  // region.
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetTeamsDistributeParallelForRegion(CGF, S, Action);
  };
  llvm::Function *Fn;
  llvm::Constant *Addr;
  // Emit target region as a standalone region.
  CGM.getOpenMPRuntime().emitTargetOutlinedFunction(
      S, ParentName, Fn, Addr, /*IsOffloadEntry=*/true, CodeGen);
  assert(Fn && Addr && "Target device function emission failed.");
}

void CodeGenFunction::EmitOMPTargetTeamsDistributeParallelForDirective(
    const OMPTargetTeamsDistributeParallelForDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetTeamsDistributeParallelForRegion(CGF, S, Action);
  };
  emitCommonOMPTargetDirective(*this, S, CodeGen);
}

static void emitTargetTeamsDistributeParallelForSimdRegion(
    CodeGenFunction &CGF,
    const OMPTargetTeamsDistributeParallelForSimdDirective &S,
    PrePostActionTy &Action) {
  Action.Enter(CGF);
  auto &&CodeGenDistribute = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
    CGF.EmitOMPDistributeLoop(S, emitInnerParallelForWhenCombined,
                              S.getDistInc());
  };

  // Emit teams region as a standalone region.
  auto &&CodeGenTeams = [&S, &CodeGenDistribute](CodeGenFunction &CGF,
                                                 PrePostActionTy &Action) {
    Action.Enter(CGF);
    CodeGenFunction::OMPPrivateScope PrivateScope(CGF);
    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
    (void)PrivateScope.Privatize();
    CGF.CGM.getOpenMPRuntime().emitInlinedDirective(
        CGF, OMPD_distribute, CodeGenDistribute, /*HasCancel=*/false);
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_teams);
  };

  emitCommonOMPTeamsDirective(CGF, S, OMPD_distribute_parallel_for_simd,
                              CodeGenTeams);
  emitPostUpdateForReductionClause(CGF, S,
                                   [](CodeGenFunction &) { return nullptr; });
}

void CodeGenFunction::EmitOMPTargetTeamsDistributeParallelForSimdDeviceFunction(
    CodeGenModule &CGM, StringRef ParentName,
    const OMPTargetTeamsDistributeParallelForSimdDirective &S) {
  // Emit SPMD target teams distribute parallel for simd region as a standalone
  // region.
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetTeamsDistributeParallelForSimdRegion(CGF, S, Action);
  };
  llvm::Function *Fn;
  llvm::Constant *Addr;
  // Emit target region as a standalone region.
  CGM.getOpenMPRuntime().emitTargetOutlinedFunction(
      S, ParentName, Fn, Addr, /*IsOffloadEntry=*/true, CodeGen);
  assert(Fn && Addr && "Target device function emission failed.");
}

void CodeGenFunction::EmitOMPTargetTeamsDistributeParallelForSimdDirective(
    const OMPTargetTeamsDistributeParallelForSimdDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetTeamsDistributeParallelForSimdRegion(CGF, S, Action);
  };
  emitCommonOMPTargetDirective(*this, S, CodeGen);
}

void CodeGenFunction::EmitOMPCancellationPointDirective(
    const OMPCancellationPointDirective &S) {
  CGM.getOpenMPRuntime().emitCancellationPointCall(*this, S.getBeginLoc(),
                                                   S.getCancelRegion());
}

void CodeGenFunction::EmitOMPCancelDirective(const OMPCancelDirective &S) {
  const Expr *IfCond = nullptr;
  for (const auto *C : S.getClausesOfKind<OMPIfClause>()) {
    if (C->getNameModifier() == OMPD_unknown ||
        C->getNameModifier() == OMPD_cancel) {
      IfCond = C->getCondition();
      break;
    }
  }
  CGM.getOpenMPRuntime().emitCancelCall(*this, S.getBeginLoc(), IfCond,
                                        S.getCancelRegion());
}

CodeGenFunction::JumpDest
CodeGenFunction::getOMPCancelDestination(OpenMPDirectiveKind Kind) {
  if (Kind == OMPD_parallel || Kind == OMPD_task ||
      Kind == OMPD_target_parallel)
    return ReturnBlock;
  assert(Kind == OMPD_for || Kind == OMPD_section || Kind == OMPD_sections ||
         Kind == OMPD_parallel_sections || Kind == OMPD_parallel_for ||
         Kind == OMPD_distribute_parallel_for ||
         Kind == OMPD_target_parallel_for ||
         Kind == OMPD_teams_distribute_parallel_for ||
         Kind == OMPD_target_teams_distribute_parallel_for);
  return OMPCancelStack.getExitBlock();
}

void CodeGenFunction::EmitOMPUseDevicePtrClause(
    const OMPClause &NC, OMPPrivateScope &PrivateScope,
    const llvm::DenseMap<const ValueDecl *, Address> &CaptureDeviceAddrMap) {
  const auto &C = cast<OMPUseDevicePtrClause>(NC);
  auto OrigVarIt = C.varlist_begin();
  auto InitIt = C.inits().begin();
  for (const Expr *PvtVarIt : C.private_copies()) {
    const auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*OrigVarIt)->getDecl());
    const auto *InitVD = cast<VarDecl>(cast<DeclRefExpr>(*InitIt)->getDecl());
    const auto *PvtVD = cast<VarDecl>(cast<DeclRefExpr>(PvtVarIt)->getDecl());

    // In order to identify the right initializer we need to match the
    // declaration used by the mapping logic. In some cases we may get
    // OMPCapturedExprDecl that refers to the original declaration.
    const ValueDecl *MatchingVD = OrigVD;
    if (const auto *OED = dyn_cast<OMPCapturedExprDecl>(MatchingVD)) {
      // OMPCapturedExprDecl are used to privative fields of the current
      // structure.
      const auto *ME = cast<MemberExpr>(OED->getInit());
      assert(isa<CXXThisExpr>(ME->getBase()) &&
             "Base should be the current struct!");
      MatchingVD = ME->getMemberDecl();
    }

    // If we don't have information about the current list item, move on to
    // the next one.
    auto InitAddrIt = CaptureDeviceAddrMap.find(MatchingVD);
    if (InitAddrIt == CaptureDeviceAddrMap.end())
      continue;

    bool IsRegistered = PrivateScope.addPrivate(OrigVD, [this, OrigVD,
                                                         InitAddrIt, InitVD,
                                                         PvtVD]() {
      // Initialize the temporary initialization variable with the address we
      // get from the runtime library. We have to cast the source address
      // because it is always a void *. References are materialized in the
      // privatization scope, so the initialization here disregards the fact
      // the original variable is a reference.
      QualType AddrQTy =
          getContext().getPointerType(OrigVD->getType().getNonReferenceType());
      llvm::Type *AddrTy = ConvertTypeForMem(AddrQTy);
      Address InitAddr = Builder.CreateBitCast(InitAddrIt->second, AddrTy);
      setAddrOfLocalVar(InitVD, InitAddr);

      // Emit private declaration, it will be initialized by the value we
      // declaration we just added to the local declarations map.
      EmitDecl(*PvtVD);

      // The initialization variables reached its purpose in the emission
      // of the previous declaration, so we don't need it anymore.
      LocalDeclMap.erase(InitVD);

      // Return the address of the private variable.
      return GetAddrOfLocalVar(PvtVD);
    });
    assert(IsRegistered && "firstprivate var already registered as private");
    // Silence the warning about unused variable.
    (void)IsRegistered;

    ++OrigVarIt;
    ++InitIt;
  }
}

// Generate the instructions for '#pragma omp target data' directive.
void CodeGenFunction::EmitOMPTargetDataDirective(
    const OMPTargetDataDirective &S) {
  CGOpenMPRuntime::TargetDataInfo Info(/*RequiresDevicePointerInfo=*/true);

  // Create a pre/post action to signal the privatization of the device pointer.
  // This action can be replaced by the OpenMP runtime code generation to
  // deactivate privatization.
  bool PrivatizeDevicePointers = false;
  class DevicePointerPrivActionTy : public PrePostActionTy {
    bool &PrivatizeDevicePointers;

  public:
    explicit DevicePointerPrivActionTy(bool &PrivatizeDevicePointers)
        : PrePostActionTy(), PrivatizeDevicePointers(PrivatizeDevicePointers) {}
    void Enter(CodeGenFunction &CGF) override {
      PrivatizeDevicePointers = true;
    }
  };
  DevicePointerPrivActionTy PrivAction(PrivatizeDevicePointers);

  auto &&CodeGen = [&S, &Info, &PrivatizeDevicePointers](
                       CodeGenFunction &CGF, PrePostActionTy &Action) {
    auto &&InnermostCodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &) {
      CGF.EmitStmt(S.getInnermostCapturedStmt()->getCapturedStmt());
    };

    // Codegen that selects whether to generate the privatization code or not.
    auto &&PrivCodeGen = [&S, &Info, &PrivatizeDevicePointers,
                          &InnermostCodeGen](CodeGenFunction &CGF,
                                             PrePostActionTy &Action) {
      RegionCodeGenTy RCG(InnermostCodeGen);
      PrivatizeDevicePointers = false;

      // Call the pre-action to change the status of PrivatizeDevicePointers if
      // needed.
      Action.Enter(CGF);

      if (PrivatizeDevicePointers) {
        OMPPrivateScope PrivateScope(CGF);
        // Emit all instances of the use_device_ptr clause.
        for (const auto *C : S.getClausesOfKind<OMPUseDevicePtrClause>())
          CGF.EmitOMPUseDevicePtrClause(*C, PrivateScope,
                                        Info.CaptureDeviceAddrMap);
        (void)PrivateScope.Privatize();
        RCG(CGF);
      } else {
        RCG(CGF);
      }
    };

    // Forward the provided action to the privatization codegen.
    RegionCodeGenTy PrivRCG(PrivCodeGen);
    PrivRCG.setAction(Action);

    // Notwithstanding the body of the region is emitted as inlined directive,
    // we don't use an inline scope as changes in the references inside the
    // region are expected to be visible outside, so we do not privative them.
    OMPLexicalScope Scope(CGF, S);
    CGF.CGM.getOpenMPRuntime().emitInlinedDirective(CGF, OMPD_target_data,
                                                    PrivRCG);
  };

  RegionCodeGenTy RCG(CodeGen);

  // If we don't have target devices, don't bother emitting the data mapping
  // code.
  if (CGM.getLangOpts().OMPTargetTriples.empty()) {
    RCG(*this);
    return;
  }

  // Check if we have any if clause associated with the directive.
  const Expr *IfCond = nullptr;
  if (const auto *C = S.getSingleClause<OMPIfClause>())
    IfCond = C->getCondition();

  // Check if we have any device clause associated with the directive.
  const Expr *Device = nullptr;
  if (const auto *C = S.getSingleClause<OMPDeviceClause>())
    Device = C->getDevice();

  // Set the action to signal privatization of device pointers.
  RCG.setAction(PrivAction);

  // Emit region code.
  CGM.getOpenMPRuntime().emitTargetDataCalls(*this, S, IfCond, Device, RCG,
                                             Info);
}

void CodeGenFunction::EmitOMPTargetEnterDataDirective(
    const OMPTargetEnterDataDirective &S) {
  // If we don't have target devices, don't bother emitting the data mapping
  // code.
  if (CGM.getLangOpts().OMPTargetTriples.empty())
    return;

  // Check if we have any if clause associated with the directive.
  const Expr *IfCond = nullptr;
  if (const auto *C = S.getSingleClause<OMPIfClause>())
    IfCond = C->getCondition();

  // Check if we have any device clause associated with the directive.
  const Expr *Device = nullptr;
  if (const auto *C = S.getSingleClause<OMPDeviceClause>())
    Device = C->getDevice();

  OMPLexicalScope Scope(*this, S, OMPD_task);
  CGM.getOpenMPRuntime().emitTargetDataStandAloneCall(*this, S, IfCond, Device);
}

void CodeGenFunction::EmitOMPTargetExitDataDirective(
    const OMPTargetExitDataDirective &S) {
  // If we don't have target devices, don't bother emitting the data mapping
  // code.
  if (CGM.getLangOpts().OMPTargetTriples.empty())
    return;

  // Check if we have any if clause associated with the directive.
  const Expr *IfCond = nullptr;
  if (const auto *C = S.getSingleClause<OMPIfClause>())
    IfCond = C->getCondition();

  // Check if we have any device clause associated with the directive.
  const Expr *Device = nullptr;
  if (const auto *C = S.getSingleClause<OMPDeviceClause>())
    Device = C->getDevice();

  OMPLexicalScope Scope(*this, S, OMPD_task);
  CGM.getOpenMPRuntime().emitTargetDataStandAloneCall(*this, S, IfCond, Device);
}

static void emitTargetParallelRegion(CodeGenFunction &CGF,
                                     const OMPTargetParallelDirective &S,
                                     PrePostActionTy &Action) {
  // Get the captured statement associated with the 'parallel' region.
  const CapturedStmt *CS = S.getCapturedStmt(OMPD_parallel);
  Action.Enter(CGF);
  auto &&CodeGen = [&S, CS](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    CodeGenFunction::OMPPrivateScope PrivateScope(CGF);
    (void)CGF.EmitOMPFirstprivateClause(S, PrivateScope);
    CGF.EmitOMPPrivateClause(S, PrivateScope);
    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
    (void)PrivateScope.Privatize();
    if (isOpenMPTargetExecutionDirective(S.getDirectiveKind()))
      CGF.CGM.getOpenMPRuntime().adjustTargetSpecificDataForLambdas(CGF, S);
    // TODO: Add support for clauses.
    CGF.EmitStmt(CS->getCapturedStmt());
    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_parallel);
  };
  emitCommonOMPParallelDirective(CGF, S, OMPD_parallel, CodeGen,
                                 emitEmptyBoundParameters);
  emitPostUpdateForReductionClause(CGF, S,
                                   [](CodeGenFunction &) { return nullptr; });
}

void CodeGenFunction::EmitOMPTargetParallelDeviceFunction(
    CodeGenModule &CGM, StringRef ParentName,
    const OMPTargetParallelDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetParallelRegion(CGF, S, Action);
  };
  llvm::Function *Fn;
  llvm::Constant *Addr;
  // Emit target region as a standalone region.
  CGM.getOpenMPRuntime().emitTargetOutlinedFunction(
      S, ParentName, Fn, Addr, /*IsOffloadEntry=*/true, CodeGen);
  assert(Fn && Addr && "Target device function emission failed.");
}

void CodeGenFunction::EmitOMPTargetParallelDirective(
    const OMPTargetParallelDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetParallelRegion(CGF, S, Action);
  };
  emitCommonOMPTargetDirective(*this, S, CodeGen);
}

static void emitTargetParallelForRegion(CodeGenFunction &CGF,
                                        const OMPTargetParallelForDirective &S,
                                        PrePostActionTy &Action) {
  Action.Enter(CGF);
  // Emit directive as a combined directive that consists of two implicit
  // directives: 'parallel' with 'for' directive.
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    CodeGenFunction::OMPCancelStackRAII CancelRegion(
        CGF, OMPD_target_parallel_for, S.hasCancel());
    CGF.EmitOMPWorksharingLoop(S, S.getEnsureUpperBound(), emitForLoopBounds,
                               emitDispatchForLoopBounds);
  };
  emitCommonOMPParallelDirective(CGF, S, OMPD_for, CodeGen,
                                 emitEmptyBoundParameters);
}

void CodeGenFunction::EmitOMPTargetParallelForDeviceFunction(
    CodeGenModule &CGM, StringRef ParentName,
    const OMPTargetParallelForDirective &S) {
  // Emit SPMD target parallel for region as a standalone region.
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetParallelForRegion(CGF, S, Action);
  };
  llvm::Function *Fn;
  llvm::Constant *Addr;
  // Emit target region as a standalone region.
  CGM.getOpenMPRuntime().emitTargetOutlinedFunction(
      S, ParentName, Fn, Addr, /*IsOffloadEntry=*/true, CodeGen);
  assert(Fn && Addr && "Target device function emission failed.");
}

void CodeGenFunction::EmitOMPTargetParallelForDirective(
    const OMPTargetParallelForDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetParallelForRegion(CGF, S, Action);
  };
  emitCommonOMPTargetDirective(*this, S, CodeGen);
}

static void
emitTargetParallelForSimdRegion(CodeGenFunction &CGF,
                                const OMPTargetParallelForSimdDirective &S,
                                PrePostActionTy &Action) {
  Action.Enter(CGF);
  // Emit directive as a combined directive that consists of two implicit
  // directives: 'parallel' with 'for' directive.
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    CGF.EmitOMPWorksharingLoop(S, S.getEnsureUpperBound(), emitForLoopBounds,
                               emitDispatchForLoopBounds);
  };
  emitCommonOMPParallelDirective(CGF, S, OMPD_simd, CodeGen,
                                 emitEmptyBoundParameters);
}

void CodeGenFunction::EmitOMPTargetParallelForSimdDeviceFunction(
    CodeGenModule &CGM, StringRef ParentName,
    const OMPTargetParallelForSimdDirective &S) {
  // Emit SPMD target parallel for region as a standalone region.
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetParallelForSimdRegion(CGF, S, Action);
  };
  llvm::Function *Fn;
  llvm::Constant *Addr;
  // Emit target region as a standalone region.
  CGM.getOpenMPRuntime().emitTargetOutlinedFunction(
      S, ParentName, Fn, Addr, /*IsOffloadEntry=*/true, CodeGen);
  assert(Fn && Addr && "Target device function emission failed.");
}

void CodeGenFunction::EmitOMPTargetParallelForSimdDirective(
    const OMPTargetParallelForSimdDirective &S) {
  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    emitTargetParallelForSimdRegion(CGF, S, Action);
  };
  emitCommonOMPTargetDirective(*this, S, CodeGen);
}

/// Emit a helper variable and return corresponding lvalue.
static void mapParam(CodeGenFunction &CGF, const DeclRefExpr *Helper,
                     const ImplicitParamDecl *PVD,
                     CodeGenFunction::OMPPrivateScope &Privates) {
  const auto *VDecl = cast<VarDecl>(Helper->getDecl());
  Privates.addPrivate(VDecl,
                      [&CGF, PVD]() { return CGF.GetAddrOfLocalVar(PVD); });
}

void CodeGenFunction::EmitOMPTaskLoopBasedDirective(const OMPLoopDirective &S) {
  assert(isOpenMPTaskLoopDirective(S.getDirectiveKind()));
  // Emit outlined function for task construct.
  const CapturedStmt *CS = S.getCapturedStmt(OMPD_taskloop);
  Address CapturedStruct = GenerateCapturedStmtArgument(*CS);
  QualType SharedsTy = getContext().getRecordType(CS->getCapturedRecordDecl());
  const Expr *IfCond = nullptr;
  for (const auto *C : S.getClausesOfKind<OMPIfClause>()) {
    if (C->getNameModifier() == OMPD_unknown ||
        C->getNameModifier() == OMPD_taskloop) {
      IfCond = C->getCondition();
      break;
    }
  }

  OMPTaskDataTy Data;
  // Check if taskloop must be emitted without taskgroup.
  Data.Nogroup = S.getSingleClause<OMPNogroupClause>();
  // TODO: Check if we should emit tied or untied task.
  Data.Tied = true;
  // Set scheduling for taskloop
  if (const auto* Clause = S.getSingleClause<OMPGrainsizeClause>()) {
    // grainsize clause
    Data.Schedule.setInt(/*IntVal=*/false);
    Data.Schedule.setPointer(EmitScalarExpr(Clause->getGrainsize()));
  } else if (const auto* Clause = S.getSingleClause<OMPNumTasksClause>()) {
    // num_tasks clause
    Data.Schedule.setInt(/*IntVal=*/true);
    Data.Schedule.setPointer(EmitScalarExpr(Clause->getNumTasks()));
  }

  auto &&BodyGen = [CS, &S](CodeGenFunction &CGF, PrePostActionTy &) {
    // if (PreCond) {
    //   for (IV in 0..LastIteration) BODY;
    //   <Final counter/linear vars updates>;
    // }
    //

    // Emit: if (PreCond) - begin.
    // If the condition constant folds and can be elided, avoid emitting the
    // whole loop.
    bool CondConstant;
    llvm::BasicBlock *ContBlock = nullptr;
    OMPLoopScope PreInitScope(CGF, S);
    if (CGF.ConstantFoldsToSimpleInteger(S.getPreCond(), CondConstant)) {
      if (!CondConstant)
        return;
    } else {
      llvm::BasicBlock *ThenBlock = CGF.createBasicBlock("taskloop.if.then");
      ContBlock = CGF.createBasicBlock("taskloop.if.end");
      emitPreCond(CGF, S, S.getPreCond(), ThenBlock, ContBlock,
                  CGF.getProfileCount(&S));
      CGF.EmitBlock(ThenBlock);
      CGF.incrementProfileCounter(&S);
    }

    (void)CGF.EmitOMPLinearClauseInit(S);

    OMPPrivateScope LoopScope(CGF);
    // Emit helper vars inits.
    enum { LowerBound = 5, UpperBound, Stride, LastIter };
    auto *I = CS->getCapturedDecl()->param_begin();
    auto *LBP = std::next(I, LowerBound);
    auto *UBP = std::next(I, UpperBound);
    auto *STP = std::next(I, Stride);
    auto *LIP = std::next(I, LastIter);
    mapParam(CGF, cast<DeclRefExpr>(S.getLowerBoundVariable()), *LBP,
             LoopScope);
    mapParam(CGF, cast<DeclRefExpr>(S.getUpperBoundVariable()), *UBP,
             LoopScope);
    mapParam(CGF, cast<DeclRefExpr>(S.getStrideVariable()), *STP, LoopScope);
    mapParam(CGF, cast<DeclRefExpr>(S.getIsLastIterVariable()), *LIP,
             LoopScope);
    CGF.EmitOMPPrivateLoopCounters(S, LoopScope);
    CGF.EmitOMPLinearClause(S, LoopScope);
    bool HasLastprivateClause = CGF.EmitOMPLastprivateClauseInit(S, LoopScope);
    (void)LoopScope.Privatize();
    // Emit the loop iteration variable.
    const Expr *IVExpr = S.getIterationVariable();
    const auto *IVDecl = cast<VarDecl>(cast<DeclRefExpr>(IVExpr)->getDecl());
    CGF.EmitVarDecl(*IVDecl);
    CGF.EmitIgnoredExpr(S.getInit());

    // Emit the iterations count variable.
    // If it is not a variable, Sema decided to calculate iterations count on
    // each iteration (e.g., it is foldable into a constant).
    if (const auto *LIExpr = dyn_cast<DeclRefExpr>(S.getLastIteration())) {
      CGF.EmitVarDecl(*cast<VarDecl>(LIExpr->getDecl()));
      // Emit calculation of the iterations count.
      CGF.EmitIgnoredExpr(S.getCalcLastIteration());
    }

    {
      OMPLexicalScope Scope(CGF, S, OMPD_taskloop, /*EmitPreInitStmt=*/false);
      emitCommonSimdLoop(
          CGF, S,
          [&S](CodeGenFunction &CGF, PrePostActionTy &) {
            if (isOpenMPSimdDirective(S.getDirectiveKind()))
              CGF.EmitOMPSimdInit(S);
          },
          [&S, &LoopScope](CodeGenFunction &CGF, PrePostActionTy &) {
            CGF.EmitOMPInnerLoop(
                S, LoopScope.requiresCleanups(), S.getCond(), S.getInc(),
                [&S](CodeGenFunction &CGF) {
                  CGF.EmitOMPLoopBody(S, CodeGenFunction::JumpDest());
                  CGF.EmitStopPoint(&S);
                },
                [](CodeGenFunction &) {});
          });
    }
    // Emit: if (PreCond) - end.
    if (ContBlock) {
      CGF.EmitBranch(ContBlock);
      CGF.EmitBlock(ContBlock, true);
    }
    // Emit final copy of the lastprivate variables if IsLastIter != 0.
    if (HasLastprivateClause) {
      CGF.EmitOMPLastprivateClauseFinal(
          S, isOpenMPSimdDirective(S.getDirectiveKind()),
          CGF.Builder.CreateIsNotNull(CGF.EmitLoadOfScalar(
              CGF.GetAddrOfLocalVar(*LIP), /*Volatile=*/false,
              (*LIP)->getType(), S.getBeginLoc())));
    }
    CGF.EmitOMPLinearClauseFinal(S, [LIP, &S](CodeGenFunction &CGF) {
      return CGF.Builder.CreateIsNotNull(
          CGF.EmitLoadOfScalar(CGF.GetAddrOfLocalVar(*LIP), /*Volatile=*/false,
                               (*LIP)->getType(), S.getBeginLoc()));
    });
  };
  auto &&TaskGen = [&S, SharedsTy, CapturedStruct,
                    IfCond](CodeGenFunction &CGF, llvm::Function *OutlinedFn,
                            const OMPTaskDataTy &Data) {
    auto &&CodeGen = [&S, OutlinedFn, SharedsTy, CapturedStruct, IfCond,
                      &Data](CodeGenFunction &CGF, PrePostActionTy &) {
      OMPLoopScope PreInitScope(CGF, S);
      CGF.CGM.getOpenMPRuntime().emitTaskLoopCall(CGF, S.getBeginLoc(), S,
                                                  OutlinedFn, SharedsTy,
                                                  CapturedStruct, IfCond, Data);
    };
    CGF.CGM.getOpenMPRuntime().emitInlinedDirective(CGF, OMPD_taskloop,
                                                    CodeGen);
  };
  if (Data.Nogroup) {
    EmitOMPTaskBasedDirective(S, OMPD_taskloop, BodyGen, TaskGen, Data);
  } else {
    CGM.getOpenMPRuntime().emitTaskgroupRegion(
        *this,
        [&S, &BodyGen, &TaskGen, &Data](CodeGenFunction &CGF,
                                        PrePostActionTy &Action) {
          Action.Enter(CGF);
          CGF.EmitOMPTaskBasedDirective(S, OMPD_taskloop, BodyGen, TaskGen,
                                        Data);
        },
        S.getBeginLoc());
  }
}

void CodeGenFunction::EmitOMPTaskLoopDirective(const OMPTaskLoopDirective &S) {
  EmitOMPTaskLoopBasedDirective(S);
}

void CodeGenFunction::EmitOMPTaskLoopSimdDirective(
    const OMPTaskLoopSimdDirective &S) {
  OMPLexicalScope Scope(*this, S);
  EmitOMPTaskLoopBasedDirective(S);
}

void CodeGenFunction::EmitOMPMasterTaskLoopDirective(
    const OMPMasterTaskLoopDirective &S) {
  auto &&CodeGen = [this, &S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    EmitOMPTaskLoopBasedDirective(S);
  };
  OMPLexicalScope Scope(*this, S, llvm::None, /*EmitPreInitStmt=*/false);
  CGM.getOpenMPRuntime().emitMasterRegion(*this, CodeGen, S.getBeginLoc());
}

void CodeGenFunction::EmitOMPMasterTaskLoopSimdDirective(
    const OMPMasterTaskLoopSimdDirective &S) {
  auto &&CodeGen = [this, &S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    Action.Enter(CGF);
    EmitOMPTaskLoopBasedDirective(S);
  };
  OMPLexicalScope Scope(*this, S);
  CGM.getOpenMPRuntime().emitMasterRegion(*this, CodeGen, S.getBeginLoc());
}

void CodeGenFunction::EmitOMPParallelMasterTaskLoopDirective(
    const OMPParallelMasterTaskLoopDirective &S) {
  auto &&CodeGen = [this, &S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    auto &&TaskLoopCodeGen = [&S](CodeGenFunction &CGF,
                                  PrePostActionTy &Action) {
      Action.Enter(CGF);
      CGF.EmitOMPTaskLoopBasedDirective(S);
    };
    OMPLexicalScope Scope(CGF, S, llvm::None, /*EmitPreInitStmt=*/false);
    CGM.getOpenMPRuntime().emitMasterRegion(CGF, TaskLoopCodeGen,
                                            S.getBeginLoc());
  };
  emitCommonOMPParallelDirective(*this, S, OMPD_master_taskloop, CodeGen,
                                 emitEmptyBoundParameters);
}

void CodeGenFunction::EmitOMPParallelMasterTaskLoopSimdDirective(
    const OMPParallelMasterTaskLoopSimdDirective &S) {
  auto &&CodeGen = [this, &S](CodeGenFunction &CGF, PrePostActionTy &Action) {
    auto &&TaskLoopCodeGen = [&S](CodeGenFunction &CGF,
                                  PrePostActionTy &Action) {
      Action.Enter(CGF);
      CGF.EmitOMPTaskLoopBasedDirective(S);
    };
    OMPLexicalScope Scope(CGF, S, OMPD_parallel, /*EmitPreInitStmt=*/false);
    CGM.getOpenMPRuntime().emitMasterRegion(CGF, TaskLoopCodeGen,
                                            S.getBeginLoc());
  };
  emitCommonOMPParallelDirective(*this, S, OMPD_master_taskloop_simd, CodeGen,
                                 emitEmptyBoundParameters);
}

// Generate the instructions for '#pragma omp target update' directive.
void CodeGenFunction::EmitOMPTargetUpdateDirective(
    const OMPTargetUpdateDirective &S) {
  // If we don't have target devices, don't bother emitting the data mapping
  // code.
  if (CGM.getLangOpts().OMPTargetTriples.empty())
    return;

  // Check if we have any if clause associated with the directive.
  const Expr *IfCond = nullptr;
  if (const auto *C = S.getSingleClause<OMPIfClause>())
    IfCond = C->getCondition();

  // Check if we have any device clause associated with the directive.
  const Expr *Device = nullptr;
  if (const auto *C = S.getSingleClause<OMPDeviceClause>())
    Device = C->getDevice();

  OMPLexicalScope Scope(*this, S, OMPD_task);
  CGM.getOpenMPRuntime().emitTargetDataStandAloneCall(*this, S, IfCond, Device);
}

void CodeGenFunction::EmitSimpleOMPExecutableDirective(
    const OMPExecutableDirective &D) {
  if (!D.hasAssociatedStmt() || !D.getAssociatedStmt())
    return;
  auto &&CodeGen = [&D](CodeGenFunction &CGF, PrePostActionTy &Action) {
    if (isOpenMPSimdDirective(D.getDirectiveKind())) {
      emitOMPSimdRegion(CGF, cast<OMPLoopDirective>(D), Action);
    } else {
      OMPPrivateScope LoopGlobals(CGF);
      if (const auto *LD = dyn_cast<OMPLoopDirective>(&D)) {
        for (const Expr *E : LD->counters()) {
          const auto *VD = dyn_cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
          if (!VD->hasLocalStorage() && !CGF.LocalDeclMap.count(VD)) {
            LValue GlobLVal = CGF.EmitLValue(E);
            LoopGlobals.addPrivate(
                VD, [&GlobLVal, &CGF]() { return GlobLVal.getAddress(CGF); });
          }
          if (isa<OMPCapturedExprDecl>(VD)) {
            // Emit only those that were not explicitly referenced in clauses.
            if (!CGF.LocalDeclMap.count(VD))
              CGF.EmitVarDecl(*VD);
          }
        }
        for (const auto *C : D.getClausesOfKind<OMPOrderedClause>()) {
          if (!C->getNumForLoops())
            continue;
          for (unsigned I = LD->getCollapsedNumber(),
                        E = C->getLoopNumIterations().size();
               I < E; ++I) {
            if (const auto *VD = dyn_cast<OMPCapturedExprDecl>(
                    cast<DeclRefExpr>(C->getLoopCounter(I))->getDecl())) {
              // Emit only those that were not explicitly referenced in clauses.
              if (!CGF.LocalDeclMap.count(VD))
                CGF.EmitVarDecl(*VD);
            }
          }
        }
      }
      LoopGlobals.Privatize();
      CGF.EmitStmt(D.getInnermostCapturedStmt()->getCapturedStmt());
    }
  };
  OMPSimdLexicalScope Scope(*this, D);
  CGM.getOpenMPRuntime().emitInlinedDirective(
      *this,
      isOpenMPSimdDirective(D.getDirectiveKind()) ? OMPD_simd
                                                  : D.getDirectiveKind(),
      CodeGen);
}