clang/lib/CodeGen/CGOpenMPRuntime.cpp

//===----- CGOpenMPRuntime.cpp - Interface to OpenMP Runtimes -------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This provides a class for OpenMP runtime code generation.
//
//===----------------------------------------------------------------------===//

#include "CGOpenMPRuntime.h"
#include "CodeGenFunction.h"
#include "CGCleanup.h"
#include "clang/AST/Decl.h"
#include "clang/AST/StmtOpenMP.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>

using namespace clang;
using namespace CodeGen;

namespace {
/// \brief Base class for handling code generation inside OpenMP regions.
class CGOpenMPRegionInfo : public CodeGenFunction::CGCapturedStmtInfo {
public:
  /// \brief Kinds of OpenMP regions used in codegen.
  enum CGOpenMPRegionKind {
    /// \brief Region with outlined function for standalone 'parallel'
    /// directive.
    ParallelOutlinedRegion,
    /// \brief Region with outlined function for standalone 'task' directive.
    TaskOutlinedRegion,
    /// \brief Region for constructs that do not require function outlining,
    /// like 'for', 'sections', 'atomic' etc. directives.
    InlinedRegion,
  };

  CGOpenMPRegionInfo(const CapturedStmt &CS,
                     const CGOpenMPRegionKind RegionKind,
                     const RegionCodeGenTy &CodeGen)
      : CGCapturedStmtInfo(CS, CR_OpenMP), RegionKind(RegionKind),
        CodeGen(CodeGen) {}

  CGOpenMPRegionInfo(const CGOpenMPRegionKind RegionKind,
                     const RegionCodeGenTy &CodeGen)
      : CGCapturedStmtInfo(CR_OpenMP), RegionKind(RegionKind),
        CodeGen(CodeGen) {}

  /// \brief Get a variable or parameter for storing global thread id
  /// inside OpenMP construct.
  virtual const VarDecl *getThreadIDVariable() const = 0;

  /// \brief Emit the captured statement body.
  virtual void EmitBody(CodeGenFunction &CGF, const Stmt *S) override;

  /// \brief Get an LValue for the current ThreadID variable.
  /// \return LValue for thread id variable. This LValue always has type int32*.
  virtual LValue getThreadIDVariableLValue(CodeGenFunction &CGF);

  CGOpenMPRegionKind getRegionKind() const { return RegionKind; }

  static bool classof(const CGCapturedStmtInfo *Info) {
    return Info->getKind() == CR_OpenMP;
  }

protected:
  CGOpenMPRegionKind RegionKind;
  const RegionCodeGenTy &CodeGen;
};

/// \brief API for captured statement code generation in OpenMP constructs.
class CGOpenMPOutlinedRegionInfo : public CGOpenMPRegionInfo {
public:
  CGOpenMPOutlinedRegionInfo(const CapturedStmt &CS, const VarDecl *ThreadIDVar,
                             const RegionCodeGenTy &CodeGen)
      : CGOpenMPRegionInfo(CS, ParallelOutlinedRegion, CodeGen),
        ThreadIDVar(ThreadIDVar) {
    assert(ThreadIDVar != nullptr && "No ThreadID in OpenMP region.");
  }
  /// \brief Get a variable or parameter for storing global thread id
  /// inside OpenMP construct.
  const VarDecl *getThreadIDVariable() const override { return ThreadIDVar; }

  /// \brief Get the name of the capture helper.
  StringRef getHelperName() const override { return ".omp_outlined."; }

  static bool classof(const CGCapturedStmtInfo *Info) {
    return CGOpenMPRegionInfo::classof(Info) &&
           cast<CGOpenMPRegionInfo>(Info)->getRegionKind() ==
               ParallelOutlinedRegion;
  }

private:
  /// \brief A variable or parameter storing global thread id for OpenMP
  /// constructs.
  const VarDecl *ThreadIDVar;
};

/// \brief API for captured statement code generation in OpenMP constructs.
class CGOpenMPTaskOutlinedRegionInfo : public CGOpenMPRegionInfo {
public:
  CGOpenMPTaskOutlinedRegionInfo(const CapturedStmt &CS,
                                 const VarDecl *ThreadIDVar,
                                 const RegionCodeGenTy &CodeGen)
      : CGOpenMPRegionInfo(CS, TaskOutlinedRegion, CodeGen),
        ThreadIDVar(ThreadIDVar) {
    assert(ThreadIDVar != nullptr && "No ThreadID in OpenMP region.");
  }
  /// \brief Get a variable or parameter for storing global thread id
  /// inside OpenMP construct.
  const VarDecl *getThreadIDVariable() const override { return ThreadIDVar; }

  /// \brief Get an LValue for the current ThreadID variable.
  LValue getThreadIDVariableLValue(CodeGenFunction &CGF) override;

  /// \brief Get the name of the capture helper.
  StringRef getHelperName() const override { return ".omp_outlined."; }

  static bool classof(const CGCapturedStmtInfo *Info) {
    return CGOpenMPRegionInfo::classof(Info) &&
           cast<CGOpenMPRegionInfo>(Info)->getRegionKind() ==
               TaskOutlinedRegion;
  }

private:
  /// \brief A variable or parameter storing global thread id for OpenMP
  /// constructs.
  const VarDecl *ThreadIDVar;
};

/// \brief API for inlined captured statement code generation in OpenMP
/// constructs.
class CGOpenMPInlinedRegionInfo : public CGOpenMPRegionInfo {
public:
  CGOpenMPInlinedRegionInfo(CodeGenFunction::CGCapturedStmtInfo *OldCSI,
                            const RegionCodeGenTy &CodeGen)
      : CGOpenMPRegionInfo(InlinedRegion, CodeGen), OldCSI(OldCSI),
        OuterRegionInfo(dyn_cast_or_null<CGOpenMPRegionInfo>(OldCSI)) {}
  // \brief Retrieve the value of the context parameter.
  llvm::Value *getContextValue() const override {
    if (OuterRegionInfo)
      return OuterRegionInfo->getContextValue();
    llvm_unreachable("No context value for inlined OpenMP region");
  }
  virtual void setContextValue(llvm::Value *V) override {
    if (OuterRegionInfo) {
      OuterRegionInfo->setContextValue(V);
      return;
    }
    llvm_unreachable("No context value for inlined OpenMP region");
  }
  /// \brief Lookup the captured field decl for a variable.
  const FieldDecl *lookup(const VarDecl *VD) const override {
    if (OuterRegionInfo)
      return OuterRegionInfo->lookup(VD);
    // If there is no outer outlined region,no need to lookup in a list of
    // captured variables, we can use the original one.
    return nullptr;
  }
  FieldDecl *getThisFieldDecl() const override {
    if (OuterRegionInfo)
      return OuterRegionInfo->getThisFieldDecl();
    return nullptr;
  }
  /// \brief Get a variable or parameter for storing global thread id
  /// inside OpenMP construct.
  const VarDecl *getThreadIDVariable() const override {
    if (OuterRegionInfo)
      return OuterRegionInfo->getThreadIDVariable();
    return nullptr;
  }

  /// \brief Get the name of the capture helper.
  StringRef getHelperName() const override {
    if (auto *OuterRegionInfo = getOldCSI())
      return OuterRegionInfo->getHelperName();
    llvm_unreachable("No helper name for inlined OpenMP construct");
  }

  CodeGenFunction::CGCapturedStmtInfo *getOldCSI() const { return OldCSI; }

  static bool classof(const CGCapturedStmtInfo *Info) {
    return CGOpenMPRegionInfo::classof(Info) &&
           cast<CGOpenMPRegionInfo>(Info)->getRegionKind() == InlinedRegion;
  }

private:
  /// \brief CodeGen info about outer OpenMP region.
  CodeGenFunction::CGCapturedStmtInfo *OldCSI;
  CGOpenMPRegionInfo *OuterRegionInfo;
};

/// \brief RAII for emitting code of OpenMP constructs.
class InlinedOpenMPRegionRAII {
  CodeGenFunction &CGF;

public:
  /// \brief Constructs region for combined constructs.
  /// \param CodeGen Code generation sequence for combined directives. Includes
  /// a list of functions used for code generation of implicitly inlined
  /// regions.
  InlinedOpenMPRegionRAII(CodeGenFunction &CGF, const RegionCodeGenTy &CodeGen)
      : CGF(CGF) {
    // Start emission for the construct.
    CGF.CapturedStmtInfo =
        new CGOpenMPInlinedRegionInfo(CGF.CapturedStmtInfo, CodeGen);
  }
  ~InlinedOpenMPRegionRAII() {
    // Restore original CapturedStmtInfo only if we're done with code emission.
    auto *OldCSI =
        cast<CGOpenMPInlinedRegionInfo>(CGF.CapturedStmtInfo)->getOldCSI();
    delete CGF.CapturedStmtInfo;
    CGF.CapturedStmtInfo = OldCSI;
  }
};

} // namespace

LValue CGOpenMPRegionInfo::getThreadIDVariableLValue(CodeGenFunction &CGF) {
  return CGF.MakeNaturalAlignAddrLValue(
      CGF.Builder.CreateAlignedLoad(
          CGF.GetAddrOfLocalVar(getThreadIDVariable()),
          CGF.PointerAlignInBytes),
      getThreadIDVariable()
          ->getType()
          ->castAs<PointerType>()
          ->getPointeeType());
}

void CGOpenMPRegionInfo::EmitBody(CodeGenFunction &CGF, const Stmt * /*S*/) {
  // 1.2.2 OpenMP Language Terminology
  // Structured block - An executable statement with a single entry at the
  // top and a single exit at the bottom.
  // The point of exit cannot be a branch out of the structured block.
  // longjmp() and throw() must not violate the entry/exit criteria.
  CGF.EHStack.pushTerminate();
  {
    CodeGenFunction::RunCleanupsScope Scope(CGF);
    CodeGen(CGF);
  }
  CGF.EHStack.popTerminate();
}

LValue CGOpenMPTaskOutlinedRegionInfo::getThreadIDVariableLValue(
    CodeGenFunction &CGF) {
  return CGF.MakeNaturalAlignAddrLValue(
      CGF.GetAddrOfLocalVar(getThreadIDVariable()),
      getThreadIDVariable()->getType());
}

CGOpenMPRuntime::CGOpenMPRuntime(CodeGenModule &CGM)
    : CGM(CGM), DefaultOpenMPPSource(nullptr), KmpRoutineEntryPtrTy(nullptr) {
  IdentTy = llvm::StructType::create(
      "ident_t", CGM.Int32Ty /* reserved_1 */, CGM.Int32Ty /* flags */,
      CGM.Int32Ty /* reserved_2 */, CGM.Int32Ty /* reserved_3 */,
      CGM.Int8PtrTy /* psource */, nullptr);
  // Build void (*kmpc_micro)(kmp_int32 *global_tid, kmp_int32 *bound_tid,...)
  llvm::Type *MicroParams[] = {llvm::PointerType::getUnqual(CGM.Int32Ty),
                               llvm::PointerType::getUnqual(CGM.Int32Ty)};
  Kmpc_MicroTy = llvm::FunctionType::get(CGM.VoidTy, MicroParams, true);
  KmpCriticalNameTy = llvm::ArrayType::get(CGM.Int32Ty, /*NumElements*/ 8);
}

void CGOpenMPRuntime::clear() {
  InternalVars.clear();
}

llvm::Value *
CGOpenMPRuntime::emitParallelOutlinedFunction(const OMPExecutableDirective &D,
                                              const VarDecl *ThreadIDVar,
                                              const RegionCodeGenTy &CodeGen) {
  assert(ThreadIDVar->getType()->isPointerType() &&
         "thread id variable must be of type kmp_int32 *");
  const CapturedStmt *CS = cast<CapturedStmt>(D.getAssociatedStmt());
  CodeGenFunction CGF(CGM, true);
  CGOpenMPOutlinedRegionInfo CGInfo(*CS, ThreadIDVar, CodeGen);
  CGF.CapturedStmtInfo = &CGInfo;
  return CGF.GenerateCapturedStmtFunction(*CS);
}

llvm::Value *
CGOpenMPRuntime::emitTaskOutlinedFunction(const OMPExecutableDirective &D,
                                          const VarDecl *ThreadIDVar,
                                          const RegionCodeGenTy &CodeGen) {
  assert(!ThreadIDVar->getType()->isPointerType() &&
         "thread id variable must be of type kmp_int32 for tasks");
  auto *CS = cast<CapturedStmt>(D.getAssociatedStmt());
  CodeGenFunction CGF(CGM, true);
  CGOpenMPTaskOutlinedRegionInfo CGInfo(*CS, ThreadIDVar, CodeGen);
  CGF.CapturedStmtInfo = &CGInfo;
  return CGF.GenerateCapturedStmtFunction(*CS);
}

llvm::Value *
CGOpenMPRuntime::getOrCreateDefaultLocation(OpenMPLocationFlags Flags) {
  llvm::Value *Entry = OpenMPDefaultLocMap.lookup(Flags);
  if (!Entry) {
    if (!DefaultOpenMPPSource) {
      // Initialize default location for psource field of ident_t structure of
      // all ident_t objects. Format is ";file;function;line;column;;".
      // Taken from
      // http://llvm.org/svn/llvm-project/openmp/trunk/runtime/src/kmp_str.c
      DefaultOpenMPPSource =
          CGM.GetAddrOfConstantCString(";unknown;unknown;0;0;;");
      DefaultOpenMPPSource =
          llvm::ConstantExpr::getBitCast(DefaultOpenMPPSource, CGM.Int8PtrTy);
    }
    auto DefaultOpenMPLocation = new llvm::GlobalVariable(
        CGM.getModule(), IdentTy, /*isConstant*/ true,
        llvm::GlobalValue::PrivateLinkage, /*Initializer*/ nullptr);
    DefaultOpenMPLocation->setUnnamedAddr(true);

    llvm::Constant *Zero = llvm::ConstantInt::get(CGM.Int32Ty, 0, true);
    llvm::Constant *Values[] = {Zero,
                                llvm::ConstantInt::get(CGM.Int32Ty, Flags),
                                Zero, Zero, DefaultOpenMPPSource};
    llvm::Constant *Init = llvm::ConstantStruct::get(IdentTy, Values);
    DefaultOpenMPLocation->setInitializer(Init);
    OpenMPDefaultLocMap[Flags] = DefaultOpenMPLocation;
    return DefaultOpenMPLocation;
  }
  return Entry;
}

llvm::Value *CGOpenMPRuntime::emitUpdateLocation(CodeGenFunction &CGF,
                                                 SourceLocation Loc,
                                                 OpenMPLocationFlags Flags) {
  // If no debug info is generated - return global default location.
  if (CGM.getCodeGenOpts().getDebugInfo() == CodeGenOptions::NoDebugInfo ||
      Loc.isInvalid())
    return getOrCreateDefaultLocation(Flags);

  assert(CGF.CurFn && "No function in current CodeGenFunction.");

  llvm::Value *LocValue = nullptr;
  auto I = OpenMPLocThreadIDMap.find(CGF.CurFn);
  if (I != OpenMPLocThreadIDMap.end())
    LocValue = I->second.DebugLoc;
  // OpenMPLocThreadIDMap may have null DebugLoc and non-null ThreadID, if
  // GetOpenMPThreadID was called before this routine.
  if (LocValue == nullptr) {
    // Generate "ident_t .kmpc_loc.addr;"
    llvm::AllocaInst *AI = CGF.CreateTempAlloca(IdentTy, ".kmpc_loc.addr");
    AI->setAlignment(CGM.getDataLayout().getPrefTypeAlignment(IdentTy));
    auto &Elem = OpenMPLocThreadIDMap.FindAndConstruct(CGF.CurFn);
    Elem.second.DebugLoc = AI;
    LocValue = AI;

    CGBuilderTy::InsertPointGuard IPG(CGF.Builder);
    CGF.Builder.SetInsertPoint(CGF.AllocaInsertPt);
    CGF.Builder.CreateMemCpy(LocValue, getOrCreateDefaultLocation(Flags),
                             llvm::ConstantExpr::getSizeOf(IdentTy),
                             CGM.PointerAlignInBytes);
  }

  // char **psource = &.kmpc_loc_<flags>.addr.psource;
  auto *PSource = CGF.Builder.CreateConstInBoundsGEP2_32(IdentTy, LocValue, 0,
                                                         IdentField_PSource);

  auto OMPDebugLoc = OpenMPDebugLocMap.lookup(Loc.getRawEncoding());
  if (OMPDebugLoc == nullptr) {
    SmallString<128> Buffer2;
    llvm::raw_svector_ostream OS2(Buffer2);
    // Build debug location
    PresumedLoc PLoc = CGF.getContext().getSourceManager().getPresumedLoc(Loc);
    OS2 << ";" << PLoc.getFilename() << ";";
    if (const FunctionDecl *FD =
            dyn_cast_or_null<FunctionDecl>(CGF.CurFuncDecl)) {
      OS2 << FD->getQualifiedNameAsString();
    }
    OS2 << ";" << PLoc.getLine() << ";" << PLoc.getColumn() << ";;";
    OMPDebugLoc = CGF.Builder.CreateGlobalStringPtr(OS2.str());
    OpenMPDebugLocMap[Loc.getRawEncoding()] = OMPDebugLoc;
  }
  // *psource = ";<File>;<Function>;<Line>;<Column>;;";
  CGF.Builder.CreateStore(OMPDebugLoc, PSource);

  return LocValue;
}

llvm::Value *CGOpenMPRuntime::getThreadID(CodeGenFunction &CGF,
                                          SourceLocation Loc) {
  assert(CGF.CurFn && "No function in current CodeGenFunction.");

  llvm::Value *ThreadID = nullptr;
  // Check whether we've already cached a load of the thread id in this
  // function.
  auto I = OpenMPLocThreadIDMap.find(CGF.CurFn);
  if (I != OpenMPLocThreadIDMap.end()) {
    ThreadID = I->second.ThreadID;
    if (ThreadID != nullptr)
      return ThreadID;
  }
  if (auto OMPRegionInfo =
          dyn_cast_or_null<CGOpenMPRegionInfo>(CGF.CapturedStmtInfo)) {
    if (OMPRegionInfo->getThreadIDVariable()) {
      // Check if this an outlined function with thread id passed as argument.
      auto LVal = OMPRegionInfo->getThreadIDVariableLValue(CGF);
      ThreadID = CGF.EmitLoadOfLValue(LVal, Loc).getScalarVal();
      // If value loaded in entry block, cache it and use it everywhere in
      // function.
      if (CGF.Builder.GetInsertBlock() == CGF.AllocaInsertPt->getParent()) {
        auto &Elem = OpenMPLocThreadIDMap.FindAndConstruct(CGF.CurFn);
        Elem.second.ThreadID = ThreadID;
      }
      return ThreadID;
    }
  }

  // This is not an outlined function region - need to call __kmpc_int32
  // kmpc_global_thread_num(ident_t *loc).
  // Generate thread id value and cache this value for use across the
  // function.
  CGBuilderTy::InsertPointGuard IPG(CGF.Builder);
  CGF.Builder.SetInsertPoint(CGF.AllocaInsertPt);
  ThreadID =
      CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_global_thread_num),
                          emitUpdateLocation(CGF, Loc));
  auto &Elem = OpenMPLocThreadIDMap.FindAndConstruct(CGF.CurFn);
  Elem.second.ThreadID = ThreadID;
  return ThreadID;
}

void CGOpenMPRuntime::functionFinished(CodeGenFunction &CGF) {
  assert(CGF.CurFn && "No function in current CodeGenFunction.");
  if (OpenMPLocThreadIDMap.count(CGF.CurFn))
    OpenMPLocThreadIDMap.erase(CGF.CurFn);
}

llvm::Type *CGOpenMPRuntime::getIdentTyPointerTy() {
  return llvm::PointerType::getUnqual(IdentTy);
}

llvm::Type *CGOpenMPRuntime::getKmpc_MicroPointerTy() {
  return llvm::PointerType::getUnqual(Kmpc_MicroTy);
}

llvm::Constant *
CGOpenMPRuntime::createRuntimeFunction(OpenMPRTLFunction Function) {
  llvm::Constant *RTLFn = nullptr;
  switch (Function) {
  case OMPRTL__kmpc_fork_call: {
    // Build void __kmpc_fork_call(ident_t *loc, kmp_int32 argc, kmpc_micro
    // microtask, ...);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty,
                                getKmpc_MicroPointerTy()};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ true);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_fork_call");
    break;
  }
  case OMPRTL__kmpc_global_thread_num: {
    // Build kmp_int32 __kmpc_global_thread_num(ident_t *loc);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy()};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.Int32Ty, TypeParams, /*isVarArg*/ false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_global_thread_num");
    break;
  }
  case OMPRTL__kmpc_threadprivate_cached: {
    // Build void *__kmpc_threadprivate_cached(ident_t *loc,
    // kmp_int32 global_tid, void *data, size_t size, void ***cache);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty,
                                CGM.VoidPtrTy, CGM.SizeTy,
                                CGM.VoidPtrTy->getPointerTo()->getPointerTo()};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidPtrTy, TypeParams, /*isVarArg*/ false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_threadprivate_cached");
    break;
  }
  case OMPRTL__kmpc_critical: {
    // Build void __kmpc_critical(ident_t *loc, kmp_int32 global_tid,
    // kmp_critical_name *crit);
    llvm::Type *TypeParams[] = {
        getIdentTyPointerTy(), CGM.Int32Ty,
        llvm::PointerType::getUnqual(KmpCriticalNameTy)};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_critical");
    break;
  }
  case OMPRTL__kmpc_threadprivate_register: {
    // Build void __kmpc_threadprivate_register(ident_t *, void *data,
    // kmpc_ctor ctor, kmpc_cctor cctor, kmpc_dtor dtor);
    // typedef void *(*kmpc_ctor)(void *);
    auto KmpcCtorTy =
        llvm::FunctionType::get(CGM.VoidPtrTy, CGM.VoidPtrTy,
                                /*isVarArg*/ false)->getPointerTo();
    // typedef void *(*kmpc_cctor)(void *, void *);
    llvm::Type *KmpcCopyCtorTyArgs[] = {CGM.VoidPtrTy, CGM.VoidPtrTy};
    auto KmpcCopyCtorTy =
        llvm::FunctionType::get(CGM.VoidPtrTy, KmpcCopyCtorTyArgs,
                                /*isVarArg*/ false)->getPointerTo();
    // typedef void (*kmpc_dtor)(void *);
    auto KmpcDtorTy =
        llvm::FunctionType::get(CGM.VoidTy, CGM.VoidPtrTy, /*isVarArg*/ false)
            ->getPointerTo();
    llvm::Type *FnTyArgs[] = {getIdentTyPointerTy(), CGM.VoidPtrTy, KmpcCtorTy,
                              KmpcCopyCtorTy, KmpcDtorTy};
    auto FnTy = llvm::FunctionType::get(CGM.VoidTy, FnTyArgs,
                                        /*isVarArg*/ false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_threadprivate_register");
    break;
  }
  case OMPRTL__kmpc_end_critical: {
    // Build void __kmpc_end_critical(ident_t *loc, kmp_int32 global_tid,
    // kmp_critical_name *crit);
    llvm::Type *TypeParams[] = {
        getIdentTyPointerTy(), CGM.Int32Ty,
        llvm::PointerType::getUnqual(KmpCriticalNameTy)};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_end_critical");
    break;
  }
  case OMPRTL__kmpc_cancel_barrier: {
    // Build kmp_int32 __kmpc_cancel_barrier(ident_t *loc, kmp_int32
    // global_tid);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.Int32Ty, TypeParams, /*isVarArg*/ false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, /*Name*/ "__kmpc_cancel_barrier");
    break;
  }
  case OMPRTL__kmpc_for_static_fini: {
    // Build void __kmpc_for_static_fini(ident_t *loc, kmp_int32 global_tid);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_for_static_fini");
    break;
  }
  case OMPRTL__kmpc_push_num_threads: {
    // Build void __kmpc_push_num_threads(ident_t *loc, kmp_int32 global_tid,
    // kmp_int32 num_threads)
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty,
                                CGM.Int32Ty};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_push_num_threads");
    break;
  }
  case OMPRTL__kmpc_serialized_parallel: {
    // Build void __kmpc_serialized_parallel(ident_t *loc, kmp_int32
    // global_tid);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_serialized_parallel");
    break;
  }
  case OMPRTL__kmpc_end_serialized_parallel: {
    // Build void __kmpc_end_serialized_parallel(ident_t *loc, kmp_int32
    // global_tid);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_end_serialized_parallel");
    break;
  }
  case OMPRTL__kmpc_flush: {
    // Build void __kmpc_flush(ident_t *loc);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy()};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_flush");
    break;
  }
  case OMPRTL__kmpc_master: {
    // Build kmp_int32 __kmpc_master(ident_t *loc, kmp_int32 global_tid);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.Int32Ty, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, /*Name=*/"__kmpc_master");
    break;
  }
  case OMPRTL__kmpc_end_master: {
    // Build void __kmpc_end_master(ident_t *loc, kmp_int32 global_tid);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, /*Name=*/"__kmpc_end_master");
    break;
  }
  case OMPRTL__kmpc_omp_taskyield: {
    // Build kmp_int32 __kmpc_omp_taskyield(ident_t *, kmp_int32 global_tid,
    // int end_part);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty, CGM.IntTy};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.Int32Ty, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, /*Name=*/"__kmpc_omp_taskyield");
    break;
  }
  case OMPRTL__kmpc_single: {
    // Build kmp_int32 __kmpc_single(ident_t *loc, kmp_int32 global_tid);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.Int32Ty, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, /*Name=*/"__kmpc_single");
    break;
  }
  case OMPRTL__kmpc_end_single: {
    // Build void __kmpc_end_single(ident_t *loc, kmp_int32 global_tid);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, /*Name=*/"__kmpc_end_single");
    break;
  }
  case OMPRTL__kmpc_omp_task_alloc: {
    // Build kmp_task_t *__kmpc_omp_task_alloc(ident_t *, kmp_int32 gtid,
    // kmp_int32 flags, size_t sizeof_kmp_task_t, size_t sizeof_shareds,
    // kmp_routine_entry_t *task_entry);
    assert(KmpRoutineEntryPtrTy != nullptr &&
           "Type kmp_routine_entry_t must be created.");
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty, CGM.Int32Ty,
                                CGM.SizeTy, CGM.SizeTy, KmpRoutineEntryPtrTy};
    // Return void * and then cast to particular kmp_task_t type.
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidPtrTy, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, /*Name=*/"__kmpc_omp_task_alloc");
    break;
  }
  case OMPRTL__kmpc_omp_task: {
    // Build kmp_int32 __kmpc_omp_task(ident_t *, kmp_int32 gtid, kmp_task_t
    // *new_task);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty,
                                CGM.VoidPtrTy};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.Int32Ty, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, /*Name=*/"__kmpc_omp_task");
    break;
  }
  case OMPRTL__kmpc_copyprivate: {
    // Build void __kmpc_copyprivate(ident_t *loc, kmp_int32 global_tid,
    // size_t cpy_size, void *cpy_data, void(*cpy_func)(void *, void *),
    // kmp_int32 didit);
    llvm::Type *CpyTypeParams[] = {CGM.VoidPtrTy, CGM.VoidPtrTy};
    auto *CpyFnTy =
        llvm::FunctionType::get(CGM.VoidTy, CpyTypeParams, /*isVarArg=*/false);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty, CGM.SizeTy,
                                CGM.VoidPtrTy, CpyFnTy->getPointerTo(),
                                CGM.Int32Ty};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, /*Name=*/"__kmpc_copyprivate");
    break;
  }
  case OMPRTL__kmpc_reduce: {
    // Build kmp_int32 __kmpc_reduce(ident_t *loc, kmp_int32 global_tid,
    // kmp_int32 num_vars, size_t reduce_size, void *reduce_data, void
    // (*reduce_func)(void *lhs_data, void *rhs_data), kmp_critical_name *lck);
    llvm::Type *ReduceTypeParams[] = {CGM.VoidPtrTy, CGM.VoidPtrTy};
    auto *ReduceFnTy = llvm::FunctionType::get(CGM.VoidTy, ReduceTypeParams,
                                               /*isVarArg=*/false);
    llvm::Type *TypeParams[] = {
        getIdentTyPointerTy(), CGM.Int32Ty, CGM.Int32Ty, CGM.SizeTy,
        CGM.VoidPtrTy, ReduceFnTy->getPointerTo(),
        llvm::PointerType::getUnqual(KmpCriticalNameTy)};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.Int32Ty, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, /*Name=*/"__kmpc_reduce");
    break;
  }
  case OMPRTL__kmpc_reduce_nowait: {
    // Build kmp_int32 __kmpc_reduce_nowait(ident_t *loc, kmp_int32
    // global_tid, kmp_int32 num_vars, size_t reduce_size, void *reduce_data,
    // void (*reduce_func)(void *lhs_data, void *rhs_data), kmp_critical_name
    // *lck);
    llvm::Type *ReduceTypeParams[] = {CGM.VoidPtrTy, CGM.VoidPtrTy};
    auto *ReduceFnTy = llvm::FunctionType::get(CGM.VoidTy, ReduceTypeParams,
                                               /*isVarArg=*/false);
    llvm::Type *TypeParams[] = {
        getIdentTyPointerTy(), CGM.Int32Ty, CGM.Int32Ty, CGM.SizeTy,
        CGM.VoidPtrTy, ReduceFnTy->getPointerTo(),
        llvm::PointerType::getUnqual(KmpCriticalNameTy)};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.Int32Ty, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, /*Name=*/"__kmpc_reduce_nowait");
    break;
  }
  case OMPRTL__kmpc_end_reduce: {
    // Build void __kmpc_end_reduce(ident_t *loc, kmp_int32 global_tid,
    // kmp_critical_name *lck);
    llvm::Type *TypeParams[] = {
        getIdentTyPointerTy(), CGM.Int32Ty,
        llvm::PointerType::getUnqual(KmpCriticalNameTy)};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, /*Name=*/"__kmpc_end_reduce");
    break;
  }
  case OMPRTL__kmpc_end_reduce_nowait: {
    // Build __kmpc_end_reduce_nowait(ident_t *loc, kmp_int32 global_tid,
    // kmp_critical_name *lck);
    llvm::Type *TypeParams[] = {
        getIdentTyPointerTy(), CGM.Int32Ty,
        llvm::PointerType::getUnqual(KmpCriticalNameTy)};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg=*/false);
    RTLFn =
        CGM.CreateRuntimeFunction(FnTy, /*Name=*/"__kmpc_end_reduce_nowait");
    break;
  }
  case OMPRTL__kmpc_omp_task_begin_if0: {
    // Build void __kmpc_omp_task(ident_t *, kmp_int32 gtid, kmp_task_t
    // *new_task);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty,
                                CGM.VoidPtrTy};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg=*/false);
    RTLFn =
        CGM.CreateRuntimeFunction(FnTy, /*Name=*/"__kmpc_omp_task_begin_if0");
    break;
  }
  case OMPRTL__kmpc_omp_task_complete_if0: {
    // Build void __kmpc_omp_task(ident_t *, kmp_int32 gtid, kmp_task_t
    // *new_task);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty,
                                CGM.VoidPtrTy};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy,
                                      /*Name=*/"__kmpc_omp_task_complete_if0");
    break;
  }
  case OMPRTL__kmpc_ordered: {
    // Build void __kmpc_ordered(ident_t *loc, kmp_int32 global_tid);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_ordered");
    break;
  }
  case OMPRTL__kmpc_end_ordered: {
    // Build void __kmpc_ordered(ident_t *loc, kmp_int32 global_tid);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_end_ordered");
    break;
  }
  case OMPRTL__kmpc_omp_taskwait: {
    // Build kmp_int32 __kmpc_omp_taskwait(ident_t *loc, kmp_int32 global_tid);
    llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty};
    llvm::FunctionType *FnTy =
        llvm::FunctionType::get(CGM.Int32Ty, TypeParams, /*isVarArg=*/false);
    RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_omp_taskwait");
    break;
  }
  }
  return RTLFn;
}

llvm::Constant *CGOpenMPRuntime::createForStaticInitFunction(unsigned IVSize,
                                                             bool IVSigned) {
  assert((IVSize == 32 || IVSize == 64) &&
         "IV size is not compatible with the omp runtime");
  auto Name = IVSize == 32 ? (IVSigned ? "__kmpc_for_static_init_4"
                                       : "__kmpc_for_static_init_4u")
                           : (IVSigned ? "__kmpc_for_static_init_8"
                                       : "__kmpc_for_static_init_8u");
  auto ITy = IVSize == 32 ? CGM.Int32Ty : CGM.Int64Ty;
  auto PtrTy = llvm::PointerType::getUnqual(ITy);
  llvm::Type *TypeParams[] = {
    getIdentTyPointerTy(),                     // loc
    CGM.Int32Ty,                               // tid
    CGM.Int32Ty,                               // schedtype
    llvm::PointerType::getUnqual(CGM.Int32Ty), // p_lastiter
    PtrTy,                                     // p_lower
    PtrTy,                                     // p_upper
    PtrTy,                                     // p_stride
    ITy,                                       // incr
    ITy                                        // chunk
  };
  llvm::FunctionType *FnTy =
      llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
  return CGM.CreateRuntimeFunction(FnTy, Name);
}

llvm::Constant *CGOpenMPRuntime::createDispatchInitFunction(unsigned IVSize,
                                                            bool IVSigned) {
  assert((IVSize == 32 || IVSize == 64) &&
         "IV size is not compatible with the omp runtime");
  auto Name =
      IVSize == 32
          ? (IVSigned ? "__kmpc_dispatch_init_4" : "__kmpc_dispatch_init_4u")
          : (IVSigned ? "__kmpc_dispatch_init_8" : "__kmpc_dispatch_init_8u");
  auto ITy = IVSize == 32 ? CGM.Int32Ty : CGM.Int64Ty;
  llvm::Type *TypeParams[] = { getIdentTyPointerTy(), // loc
                               CGM.Int32Ty,           // tid
                               CGM.Int32Ty,           // schedtype
                               ITy,                   // lower
                               ITy,                   // upper
                               ITy,                   // stride
                               ITy                    // chunk
  };
  llvm::FunctionType *FnTy =
      llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg*/ false);
  return CGM.CreateRuntimeFunction(FnTy, Name);
}

llvm::Constant *CGOpenMPRuntime::createDispatchFiniFunction(unsigned IVSize,
                                                            bool IVSigned) {
  assert((IVSize == 32 || IVSize == 64) &&
         "IV size is not compatible with the omp runtime");
  auto Name =
      IVSize == 32
          ? (IVSigned ? "__kmpc_dispatch_fini_4" : "__kmpc_dispatch_fini_4u")
          : (IVSigned ? "__kmpc_dispatch_fini_8" : "__kmpc_dispatch_fini_8u");
  llvm::Type *TypeParams[] = {
      getIdentTyPointerTy(), // loc
      CGM.Int32Ty,           // tid
  };
  llvm::FunctionType *FnTy =
      llvm::FunctionType::get(CGM.VoidTy, TypeParams, /*isVarArg=*/false);
  return CGM.CreateRuntimeFunction(FnTy, Name);
}

llvm::Constant *CGOpenMPRuntime::createDispatchNextFunction(unsigned IVSize,
                                                            bool IVSigned) {
  assert((IVSize == 32 || IVSize == 64) &&
         "IV size is not compatible with the omp runtime");
  auto Name =
      IVSize == 32
          ? (IVSigned ? "__kmpc_dispatch_next_4" : "__kmpc_dispatch_next_4u")
          : (IVSigned ? "__kmpc_dispatch_next_8" : "__kmpc_dispatch_next_8u");
  auto ITy = IVSize == 32 ? CGM.Int32Ty : CGM.Int64Ty;
  auto PtrTy = llvm::PointerType::getUnqual(ITy);
  llvm::Type *TypeParams[] = {
    getIdentTyPointerTy(),                     // loc
    CGM.Int32Ty,                               // tid
    llvm::PointerType::getUnqual(CGM.Int32Ty), // p_lastiter
    PtrTy,                                     // p_lower
    PtrTy,                                     // p_upper
    PtrTy                                      // p_stride
  };
  llvm::FunctionType *FnTy =
      llvm::FunctionType::get(CGM.Int32Ty, TypeParams, /*isVarArg*/ false);
  return CGM.CreateRuntimeFunction(FnTy, Name);
}

llvm::Constant *
CGOpenMPRuntime::getOrCreateThreadPrivateCache(const VarDecl *VD) {
  // Lookup the entry, lazily creating it if necessary.
  return getOrCreateInternalVariable(CGM.Int8PtrPtrTy,
                                     Twine(CGM.getMangledName(VD)) + ".cache.");
}

llvm::Value *CGOpenMPRuntime::getAddrOfThreadPrivate(CodeGenFunction &CGF,
                                                     const VarDecl *VD,
                                                     llvm::Value *VDAddr,
                                                     SourceLocation Loc) {
  auto VarTy = VDAddr->getType()->getPointerElementType();
  llvm::Value *Args[] = {emitUpdateLocation(CGF, Loc), getThreadID(CGF, Loc),
                         CGF.Builder.CreatePointerCast(VDAddr, CGM.Int8PtrTy),
                         CGM.getSize(CGM.GetTargetTypeStoreSize(VarTy)),
                         getOrCreateThreadPrivateCache(VD)};
  return CGF.EmitRuntimeCall(
      createRuntimeFunction(OMPRTL__kmpc_threadprivate_cached), Args);
}

void CGOpenMPRuntime::emitThreadPrivateVarInit(
    CodeGenFunction &CGF, llvm::Value *VDAddr, llvm::Value *Ctor,
    llvm::Value *CopyCtor, llvm::Value *Dtor, SourceLocation Loc) {
  // Call kmp_int32 __kmpc_global_thread_num(&loc) to init OpenMP runtime
  // library.
  auto OMPLoc = emitUpdateLocation(CGF, Loc);
  CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_global_thread_num),
                      OMPLoc);
  // Call __kmpc_threadprivate_register(&loc, &var, ctor, cctor/*NULL*/, dtor)
  // to register constructor/destructor for variable.
  llvm::Value *Args[] = {OMPLoc,
                         CGF.Builder.CreatePointerCast(VDAddr, CGM.VoidPtrTy),
                         Ctor, CopyCtor, Dtor};
  CGF.EmitRuntimeCall(
      createRuntimeFunction(OMPRTL__kmpc_threadprivate_register), Args);
}

llvm::Function *CGOpenMPRuntime::emitThreadPrivateVarDefinition(
    const VarDecl *VD, llvm::Value *VDAddr, SourceLocation Loc,
    bool PerformInit, CodeGenFunction *CGF) {
  VD = VD->getDefinition(CGM.getContext());
  if (VD && ThreadPrivateWithDefinition.count(VD) == 0) {
    ThreadPrivateWithDefinition.insert(VD);
    QualType ASTTy = VD->getType();

    llvm::Value *Ctor = nullptr, *CopyCtor = nullptr, *Dtor = nullptr;
    auto Init = VD->getAnyInitializer();
    if (CGM.getLangOpts().CPlusPlus && PerformInit) {
      // Generate function that re-emits the declaration's initializer into the
      // threadprivate copy of the variable VD
      CodeGenFunction CtorCGF(CGM);
      FunctionArgList Args;
      ImplicitParamDecl Dst(CGM.getContext(), /*DC=*/nullptr, SourceLocation(),
                            /*Id=*/nullptr, CGM.getContext().VoidPtrTy);
      Args.push_back(&Dst);

      auto &FI = CGM.getTypes().arrangeFreeFunctionDeclaration(
          CGM.getContext().VoidPtrTy, Args, FunctionType::ExtInfo(),
          /*isVariadic=*/false);
      auto FTy = CGM.getTypes().GetFunctionType(FI);
      auto Fn = CGM.CreateGlobalInitOrDestructFunction(
          FTy, ".__kmpc_global_ctor_.", Loc);
      CtorCGF.StartFunction(GlobalDecl(), CGM.getContext().VoidPtrTy, Fn, FI,
                            Args, SourceLocation());
      auto ArgVal = CtorCGF.EmitLoadOfScalar(
          CtorCGF.GetAddrOfLocalVar(&Dst),
          /*Volatile=*/false, CGM.PointerAlignInBytes,
          CGM.getContext().VoidPtrTy, Dst.getLocation());
      auto Arg = CtorCGF.Builder.CreatePointerCast(
          ArgVal,
          CtorCGF.ConvertTypeForMem(CGM.getContext().getPointerType(ASTTy)));
      CtorCGF.EmitAnyExprToMem(Init, Arg, Init->getType().getQualifiers(),
                               /*IsInitializer=*/true);
      ArgVal = CtorCGF.EmitLoadOfScalar(
          CtorCGF.GetAddrOfLocalVar(&Dst),
          /*Volatile=*/false, CGM.PointerAlignInBytes,
          CGM.getContext().VoidPtrTy, Dst.getLocation());
      CtorCGF.Builder.CreateStore(ArgVal, CtorCGF.ReturnValue);
      CtorCGF.FinishFunction();
      Ctor = Fn;
    }
    if (VD->getType().isDestructedType() != QualType::DK_none) {
      // Generate function that emits destructor call for the threadprivate copy
      // of the variable VD
      CodeGenFunction DtorCGF(CGM);
      FunctionArgList Args;
      ImplicitParamDecl Dst(CGM.getContext(), /*DC=*/nullptr, SourceLocation(),
                            /*Id=*/nullptr, CGM.getContext().VoidPtrTy);
      Args.push_back(&Dst);

      auto &FI = CGM.getTypes().arrangeFreeFunctionDeclaration(
          CGM.getContext().VoidTy, Args, FunctionType::ExtInfo(),
          /*isVariadic=*/false);
      auto FTy = CGM.getTypes().GetFunctionType(FI);
      auto Fn = CGM.CreateGlobalInitOrDestructFunction(
          FTy, ".__kmpc_global_dtor_.", Loc);
      DtorCGF.StartFunction(GlobalDecl(), CGM.getContext().VoidTy, Fn, FI, Args,
                            SourceLocation());
      auto ArgVal = DtorCGF.EmitLoadOfScalar(
          DtorCGF.GetAddrOfLocalVar(&Dst),
          /*Volatile=*/false, CGM.PointerAlignInBytes,
          CGM.getContext().VoidPtrTy, Dst.getLocation());
      DtorCGF.emitDestroy(ArgVal, ASTTy,
                          DtorCGF.getDestroyer(ASTTy.isDestructedType()),
                          DtorCGF.needsEHCleanup(ASTTy.isDestructedType()));
      DtorCGF.FinishFunction();
      Dtor = Fn;
    }
    // Do not emit init function if it is not required.
    if (!Ctor && !Dtor)
      return nullptr;

    llvm::Type *CopyCtorTyArgs[] = {CGM.VoidPtrTy, CGM.VoidPtrTy};
    auto CopyCtorTy =
        llvm::FunctionType::get(CGM.VoidPtrTy, CopyCtorTyArgs,
                                /*isVarArg=*/false)->getPointerTo();
    // Copying constructor for the threadprivate variable.
    // Must be NULL - reserved by runtime, but currently it requires that this
    // parameter is always NULL. Otherwise it fires assertion.
    CopyCtor = llvm::Constant::getNullValue(CopyCtorTy);
    if (Ctor == nullptr) {
      auto CtorTy = llvm::FunctionType::get(CGM.VoidPtrTy, CGM.VoidPtrTy,
                                            /*isVarArg=*/false)->getPointerTo();
      Ctor = llvm::Constant::getNullValue(CtorTy);
    }
    if (Dtor == nullptr) {
      auto DtorTy = llvm::FunctionType::get(CGM.VoidTy, CGM.VoidPtrTy,
                                            /*isVarArg=*/false)->getPointerTo();
      Dtor = llvm::Constant::getNullValue(DtorTy);
    }
    if (!CGF) {
      auto InitFunctionTy =
          llvm::FunctionType::get(CGM.VoidTy, /*isVarArg*/ false);
      auto InitFunction = CGM.CreateGlobalInitOrDestructFunction(
          InitFunctionTy, ".__omp_threadprivate_init_.");
      CodeGenFunction InitCGF(CGM);
      FunctionArgList ArgList;
      InitCGF.StartFunction(GlobalDecl(), CGM.getContext().VoidTy, InitFunction,
                            CGM.getTypes().arrangeNullaryFunction(), ArgList,
                            Loc);
      emitThreadPrivateVarInit(InitCGF, VDAddr, Ctor, CopyCtor, Dtor, Loc);
      InitCGF.FinishFunction();
      return InitFunction;
    }
    emitThreadPrivateVarInit(*CGF, VDAddr, Ctor, CopyCtor, Dtor, Loc);
  }
  return nullptr;
}

/// \brief Emits code for OpenMP 'if' clause using specified \a CodeGen
/// function. Here is the logic:
/// if (Cond) {
///   ThenGen();
/// } else {
///   ElseGen();
/// }
static void emitOMPIfClause(CodeGenFunction &CGF, const Expr *Cond,
                            const RegionCodeGenTy &ThenGen,
                            const RegionCodeGenTy &ElseGen) {
  CodeGenFunction::LexicalScope ConditionScope(CGF, Cond->getSourceRange());

  // If the condition constant folds and can be elided, try to avoid emitting
  // the condition and the dead arm of the if/else.
  bool CondConstant;
  if (CGF.ConstantFoldsToSimpleInteger(Cond, CondConstant)) {
    CodeGenFunction::RunCleanupsScope Scope(CGF);
    if (CondConstant) {
      ThenGen(CGF);
    } else {
      ElseGen(CGF);
    }
    return;
  }

  // Otherwise, the condition did not fold, or we couldn't elide it.  Just
  // emit the conditional branch.
  auto ThenBlock = CGF.createBasicBlock("omp_if.then");
  auto ElseBlock = CGF.createBasicBlock("omp_if.else");
  auto ContBlock = CGF.createBasicBlock("omp_if.end");
  CGF.EmitBranchOnBoolExpr(Cond, ThenBlock, ElseBlock, /*TrueCount=*/0);

  // Emit the 'then' code.
  CGF.EmitBlock(ThenBlock);
  {
    CodeGenFunction::RunCleanupsScope ThenScope(CGF);
    ThenGen(CGF);
  }
  CGF.EmitBranch(ContBlock);
  // Emit the 'else' code if present.
  {
    // There is no need to emit line number for unconditional branch.
    auto NL = ApplyDebugLocation::CreateEmpty(CGF);
    CGF.EmitBlock(ElseBlock);
  }
  {
    CodeGenFunction::RunCleanupsScope ThenScope(CGF);
    ElseGen(CGF);
  }
  {
    // There is no need to emit line number for unconditional branch.
    auto NL = ApplyDebugLocation::CreateEmpty(CGF);
    CGF.EmitBranch(ContBlock);
  }
  // Emit the continuation block for code after the if.
  CGF.EmitBlock(ContBlock, /*IsFinished=*/true);
}

void CGOpenMPRuntime::emitParallelCall(CodeGenFunction &CGF, SourceLocation Loc,
                                       llvm::Value *OutlinedFn,
                                       llvm::Value *CapturedStruct,
                                       const Expr *IfCond) {
  auto *RTLoc = emitUpdateLocation(CGF, Loc);
  auto &&ThenGen =
      [this, OutlinedFn, CapturedStruct, RTLoc](CodeGenFunction &CGF) {
        // Build call __kmpc_fork_call(loc, 1, microtask,
        // captured_struct/*context*/)
        llvm::Value *Args[] = {
            RTLoc,
            CGF.Builder.getInt32(
                1), // Number of arguments after 'microtask' argument
            // (there is only one additional argument - 'context')
            CGF.Builder.CreateBitCast(OutlinedFn, getKmpc_MicroPointerTy()),
            CGF.EmitCastToVoidPtr(CapturedStruct)};
        auto RTLFn = createRuntimeFunction(OMPRTL__kmpc_fork_call);
        CGF.EmitRuntimeCall(RTLFn, Args);
      };
  auto &&ElseGen = [this, OutlinedFn, CapturedStruct, RTLoc, Loc](
      CodeGenFunction &CGF) {
    auto ThreadID = getThreadID(CGF, Loc);
    // Build calls:
    // __kmpc_serialized_parallel(&Loc, GTid);
    llvm::Value *Args[] = {RTLoc, ThreadID};
    CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_serialized_parallel),
                        Args);

    // OutlinedFn(&GTid, &zero, CapturedStruct);
    auto ThreadIDAddr = emitThreadIDAddress(CGF, Loc);
    auto Int32Ty = CGF.getContext().getIntTypeForBitwidth(/*DestWidth*/ 32,
                                                          /*Signed*/ true);
    auto ZeroAddr = CGF.CreateMemTemp(Int32Ty, /*Name*/ ".zero.addr");
    CGF.InitTempAlloca(ZeroAddr, CGF.Builder.getInt32(/*C*/ 0));
    llvm::Value *OutlinedFnArgs[] = {ThreadIDAddr, ZeroAddr, CapturedStruct};
    CGF.EmitCallOrInvoke(OutlinedFn, OutlinedFnArgs);

    // __kmpc_end_serialized_parallel(&Loc, GTid);
    llvm::Value *EndArgs[] = {emitUpdateLocation(CGF, Loc), ThreadID};
    CGF.EmitRuntimeCall(
        createRuntimeFunction(OMPRTL__kmpc_end_serialized_parallel), EndArgs);
  };
  if (IfCond) {
    emitOMPIfClause(CGF, IfCond, ThenGen, ElseGen);
  } else {
    CodeGenFunction::RunCleanupsScope Scope(CGF);
    ThenGen(CGF);
  }
}

// If we're inside an (outlined) parallel region, use the region info's
// thread-ID variable (it is passed in a first argument of the outlined function
// as "kmp_int32 *gtid"). Otherwise, if we're not inside parallel region, but in
// regular serial code region, get thread ID by calling kmp_int32
// kmpc_global_thread_num(ident_t *loc), stash this thread ID in a temporary and
// return the address of that temp.
llvm::Value *CGOpenMPRuntime::emitThreadIDAddress(CodeGenFunction &CGF,
                                                  SourceLocation Loc) {
  if (auto OMPRegionInfo =
          dyn_cast_or_null<CGOpenMPRegionInfo>(CGF.CapturedStmtInfo))
    if (OMPRegionInfo->getThreadIDVariable())
      return OMPRegionInfo->getThreadIDVariableLValue(CGF).getAddress();

  auto ThreadID = getThreadID(CGF, Loc);
  auto Int32Ty =
      CGF.getContext().getIntTypeForBitwidth(/*DestWidth*/ 32, /*Signed*/ true);
  auto ThreadIDTemp = CGF.CreateMemTemp(Int32Ty, /*Name*/ ".threadid_temp.");
  CGF.EmitStoreOfScalar(ThreadID,
                        CGF.MakeNaturalAlignAddrLValue(ThreadIDTemp, Int32Ty));

  return ThreadIDTemp;
}

llvm::Constant *
CGOpenMPRuntime::getOrCreateInternalVariable(llvm::Type *Ty,
                                             const llvm::Twine &Name) {
  SmallString<256> Buffer;
  llvm::raw_svector_ostream Out(Buffer);
  Out << Name;
  auto RuntimeName = Out.str();
  auto &Elem = *InternalVars.insert(std::make_pair(RuntimeName, nullptr)).first;
  if (Elem.second) {
    assert(Elem.second->getType()->getPointerElementType() == Ty &&
           "OMP internal variable has different type than requested");
    return &*Elem.second;
  }

  return Elem.second = new llvm::GlobalVariable(
             CGM.getModule(), Ty, /*IsConstant*/ false,
             llvm::GlobalValue::CommonLinkage, llvm::Constant::getNullValue(Ty),
             Elem.first());
}

llvm::Value *CGOpenMPRuntime::getCriticalRegionLock(StringRef CriticalName) {
  llvm::Twine Name(".gomp_critical_user_", CriticalName);
  return getOrCreateInternalVariable(KmpCriticalNameTy, Name.concat(".var"));
}

namespace {
class CallEndCleanup : public EHScopeStack::Cleanup {
public:
  typedef ArrayRef<llvm::Value *> CleanupValuesTy;
private:
  llvm::Value *Callee;
  llvm::SmallVector<llvm::Value *, 8> Args;

public:
  CallEndCleanup(llvm::Value *Callee, CleanupValuesTy Args)
      : Callee(Callee), Args(Args.begin(), Args.end()) {}
  void Emit(CodeGenFunction &CGF, Flags /*flags*/) override {
    CGF.EmitRuntimeCall(Callee, Args);
  }
};
} // namespace

void CGOpenMPRuntime::emitCriticalRegion(CodeGenFunction &CGF,
                                         StringRef CriticalName,
                                         const RegionCodeGenTy &CriticalOpGen,
                                         SourceLocation Loc) {
  // __kmpc_critical(ident_t *, gtid, Lock);
  // CriticalOpGen();
  // __kmpc_end_critical(ident_t *, gtid, Lock);
  // Prepare arguments and build a call to __kmpc_critical
  {
    CodeGenFunction::RunCleanupsScope Scope(CGF);
    llvm::Value *Args[] = {emitUpdateLocation(CGF, Loc), getThreadID(CGF, Loc),
                           getCriticalRegionLock(CriticalName)};
    CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_critical), Args);
    // Build a call to __kmpc_end_critical
    CGF.EHStack.pushCleanup<CallEndCleanup>(
        NormalAndEHCleanup, createRuntimeFunction(OMPRTL__kmpc_end_critical),
        llvm::makeArrayRef(Args));
    emitInlinedDirective(CGF, CriticalOpGen);
  }
}

static void emitIfStmt(CodeGenFunction &CGF, llvm::Value *IfCond,
                       const RegionCodeGenTy &BodyOpGen) {
  llvm::Value *CallBool = CGF.EmitScalarConversion(
      IfCond,
      CGF.getContext().getIntTypeForBitwidth(/*DestWidth=*/32, /*Signed=*/true),
      CGF.getContext().BoolTy);

  auto *ThenBlock = CGF.createBasicBlock("omp_if.then");
  auto *ContBlock = CGF.createBasicBlock("omp_if.end");
  // Generate the branch (If-stmt)
  CGF.Builder.CreateCondBr(CallBool, ThenBlock, ContBlock);
  CGF.EmitBlock(ThenBlock);
  CGF.CGM.getOpenMPRuntime().emitInlinedDirective(CGF, BodyOpGen);
  // Emit the rest of bblocks/branches
  CGF.EmitBranch(ContBlock);
  CGF.EmitBlock(ContBlock, true);
}

void CGOpenMPRuntime::emitMasterRegion(CodeGenFunction &CGF,
                                       const RegionCodeGenTy &MasterOpGen,
                                       SourceLocation Loc) {
  // if(__kmpc_master(ident_t *, gtid)) {
  //   MasterOpGen();
  //   __kmpc_end_master(ident_t *, gtid);
  // }
  // Prepare arguments and build a call to __kmpc_master
  llvm::Value *Args[] = {emitUpdateLocation(CGF, Loc), getThreadID(CGF, Loc)};
  auto *IsMaster =
      CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_master), Args);
  emitIfStmt(CGF, IsMaster, [&](CodeGenFunction &CGF) -> void {
    CodeGenFunction::RunCleanupsScope Scope(CGF);
    CGF.EHStack.pushCleanup<CallEndCleanup>(
        NormalAndEHCleanup, createRuntimeFunction(OMPRTL__kmpc_end_master),
        llvm::makeArrayRef(Args));
    MasterOpGen(CGF);
  });
}

void CGOpenMPRuntime::emitTaskyieldCall(CodeGenFunction &CGF,
                                        SourceLocation Loc) {
  // Build call __kmpc_omp_taskyield(loc, thread_id, 0);
  llvm::Value *Args[] = {
      emitUpdateLocation(CGF, Loc), getThreadID(CGF, Loc),
      llvm::ConstantInt::get(CGM.IntTy, /*V=*/0, /*isSigned=*/true)};
  CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_omp_taskyield), Args);
}

static llvm::Value *emitCopyprivateCopyFunction(
    CodeGenModule &CGM, llvm::Type *ArgsType,
    ArrayRef<const Expr *> CopyprivateVars, ArrayRef<const Expr *> DestExprs,
    ArrayRef<const Expr *> SrcExprs, ArrayRef<const Expr *> AssignmentOps) {
  auto &C = CGM.getContext();
  // void copy_func(void *LHSArg, void *RHSArg);
  FunctionArgList Args;
  ImplicitParamDecl LHSArg(C, /*DC=*/nullptr, SourceLocation(), /*Id=*/nullptr,
                           C.VoidPtrTy);
  ImplicitParamDecl RHSArg(C, /*DC=*/nullptr, SourceLocation(), /*Id=*/nullptr,
                           C.VoidPtrTy);
  Args.push_back(&LHSArg);
  Args.push_back(&RHSArg);
  FunctionType::ExtInfo EI;
  auto &CGFI = CGM.getTypes().arrangeFreeFunctionDeclaration(
      C.VoidTy, Args, EI, /*isVariadic=*/false);
  auto *Fn = llvm::Function::Create(
      CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
      ".omp.copyprivate.copy_func", &CGM.getModule());
  CGM.SetLLVMFunctionAttributes(/*D=*/nullptr, CGFI, Fn);
  CodeGenFunction CGF(CGM);
  CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args);
  // Dest = (void*[n])(LHSArg);
  // Src = (void*[n])(RHSArg);
  auto *LHS = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
      CGF.Builder.CreateAlignedLoad(CGF.GetAddrOfLocalVar(&LHSArg),
                                    CGF.PointerAlignInBytes),
      ArgsType);
  auto *RHS = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
      CGF.Builder.CreateAlignedLoad(CGF.GetAddrOfLocalVar(&RHSArg),
                                    CGF.PointerAlignInBytes),
      ArgsType);
  // *(Type0*)Dst[0] = *(Type0*)Src[0];
  // *(Type1*)Dst[1] = *(Type1*)Src[1];
  // ...
  // *(Typen*)Dst[n] = *(Typen*)Src[n];
  for (unsigned I = 0, E = AssignmentOps.size(); I < E; ++I) {
    auto *DestAddr = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
        CGF.Builder.CreateAlignedLoad(
            CGF.Builder.CreateStructGEP(nullptr, LHS, I),
            CGM.PointerAlignInBytes),
        CGF.ConvertTypeForMem(C.getPointerType(SrcExprs[I]->getType())));
    auto *SrcAddr = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
        CGF.Builder.CreateAlignedLoad(
            CGF.Builder.CreateStructGEP(nullptr, RHS, I),
            CGM.PointerAlignInBytes),
        CGF.ConvertTypeForMem(C.getPointerType(SrcExprs[I]->getType())));
    CGF.EmitOMPCopy(CGF, CopyprivateVars[I]->getType(), DestAddr, SrcAddr,
                    cast<VarDecl>(cast<DeclRefExpr>(DestExprs[I])->getDecl()),
                    cast<VarDecl>(cast<DeclRefExpr>(SrcExprs[I])->getDecl()),
                    AssignmentOps[I]);
  }
  CGF.FinishFunction();
  return Fn;
}

void CGOpenMPRuntime::emitSingleRegion(CodeGenFunction &CGF,
                                       const RegionCodeGenTy &SingleOpGen,
                                       SourceLocation Loc,
                                       ArrayRef<const Expr *> CopyprivateVars,
                                       ArrayRef<const Expr *> SrcExprs,
                                       ArrayRef<const Expr *> DstExprs,
                                       ArrayRef<const Expr *> AssignmentOps) {
  assert(CopyprivateVars.size() == SrcExprs.size() &&
         CopyprivateVars.size() == DstExprs.size() &&
         CopyprivateVars.size() == AssignmentOps.size());
  auto &C = CGM.getContext();
  // int32 did_it = 0;
  // if(__kmpc_single(ident_t *, gtid)) {
  //   SingleOpGen();
  //   __kmpc_end_single(ident_t *, gtid);
  //   did_it = 1;
  // }
  // call __kmpc_copyprivate(ident_t *, gtid, <buf_size>, <copyprivate list>,
  // <copy_func>, did_it);

  llvm::AllocaInst *DidIt = nullptr;
  if (!CopyprivateVars.empty()) {
    // int32 did_it = 0;
    auto KmpInt32Ty = C.getIntTypeForBitwidth(/*DestWidth=*/32, /*Signed=*/1);
    DidIt = CGF.CreateMemTemp(KmpInt32Ty, ".omp.copyprivate.did_it");
    CGF.Builder.CreateAlignedStore(CGF.Builder.getInt32(0), DidIt,
                                   DidIt->getAlignment());
  }
  // Prepare arguments and build a call to __kmpc_single
  llvm::Value *Args[] = {emitUpdateLocation(CGF, Loc), getThreadID(CGF, Loc)};
  auto *IsSingle =
      CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_single), Args);
  emitIfStmt(CGF, IsSingle, [&](CodeGenFunction &CGF) -> void {
    CodeGenFunction::RunCleanupsScope Scope(CGF);
    CGF.EHStack.pushCleanup<CallEndCleanup>(
        NormalAndEHCleanup, createRuntimeFunction(OMPRTL__kmpc_end_single),
        llvm::makeArrayRef(Args));
    SingleOpGen(CGF);
    if (DidIt) {
      // did_it = 1;
      CGF.Builder.CreateAlignedStore(CGF.Builder.getInt32(1), DidIt,
                                     DidIt->getAlignment());
    }
  });
  // call __kmpc_copyprivate(ident_t *, gtid, <buf_size>, <copyprivate list>,
  // <copy_func>, did_it);
  if (DidIt) {
    llvm::APInt ArraySize(/*unsigned int numBits=*/32, CopyprivateVars.size());
    auto CopyprivateArrayTy =
        C.getConstantArrayType(C.VoidPtrTy, ArraySize, ArrayType::Normal,
                               /*IndexTypeQuals=*/0);
    // Create a list of all private variables for copyprivate.
    auto *CopyprivateList =
        CGF.CreateMemTemp(CopyprivateArrayTy, ".omp.copyprivate.cpr_list");
    for (unsigned I = 0, E = CopyprivateVars.size(); I < E; ++I) {
      auto *Elem = CGF.Builder.CreateStructGEP(
          CopyprivateList->getAllocatedType(), CopyprivateList, I);
      CGF.Builder.CreateAlignedStore(
          CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
              CGF.EmitLValue(CopyprivateVars[I]).getAddress(), CGF.VoidPtrTy),
          Elem, CGM.PointerAlignInBytes);
    }
    // Build function that copies private values from single region to all other
    // threads in the corresponding parallel region.
    auto *CpyFn = emitCopyprivateCopyFunction(
        CGM, CGF.ConvertTypeForMem(CopyprivateArrayTy)->getPointerTo(),
        CopyprivateVars, SrcExprs, DstExprs, AssignmentOps);
    auto *BufSize = llvm::ConstantInt::get(
        CGM.SizeTy, C.getTypeSizeInChars(CopyprivateArrayTy).getQuantity());
    auto *CL = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(CopyprivateList,
                                                               CGF.VoidPtrTy);
    auto *DidItVal =
        CGF.Builder.CreateAlignedLoad(DidIt, CGF.PointerAlignInBytes);
    llvm::Value *Args[] = {
        emitUpdateLocation(CGF, Loc), // ident_t *<loc>
        getThreadID(CGF, Loc),        // i32 <gtid>
        BufSize,                      // size_t <buf_size>
        CL,                           // void *<copyprivate list>
        CpyFn,                        // void (*) (void *, void *) <copy_func>
        DidItVal                      // i32 did_it
    };
    CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_copyprivate), Args);
  }
}

void CGOpenMPRuntime::emitOrderedRegion(CodeGenFunction &CGF,
                                        const RegionCodeGenTy &OrderedOpGen,
                                        SourceLocation Loc) {
  // __kmpc_ordered(ident_t *, gtid);
  // OrderedOpGen();
  // __kmpc_end_ordered(ident_t *, gtid);
  // Prepare arguments and build a call to __kmpc_ordered
  {
    CodeGenFunction::RunCleanupsScope Scope(CGF);
    llvm::Value *Args[] = {emitUpdateLocation(CGF, Loc), getThreadID(CGF, Loc)};
    CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_ordered), Args);
    // Build a call to __kmpc_end_ordered
    CGF.EHStack.pushCleanup<CallEndCleanup>(
        NormalAndEHCleanup, createRuntimeFunction(OMPRTL__kmpc_end_ordered),
        llvm::makeArrayRef(Args));
    emitInlinedDirective(CGF, OrderedOpGen);
  }
}

void CGOpenMPRuntime::emitBarrierCall(CodeGenFunction &CGF, SourceLocation Loc,
                                      OpenMPDirectiveKind Kind) {
  // Build call __kmpc_cancel_barrier(loc, thread_id);
  OpenMPLocationFlags Flags = OMP_IDENT_KMPC;
  if (Kind == OMPD_for) {
    Flags =
        static_cast<OpenMPLocationFlags>(Flags | OMP_IDENT_BARRIER_IMPL_FOR);
  } else if (Kind == OMPD_sections) {
    Flags = static_cast<OpenMPLocationFlags>(Flags |
                                             OMP_IDENT_BARRIER_IMPL_SECTIONS);
  } else if (Kind == OMPD_single) {
    Flags =
        static_cast<OpenMPLocationFlags>(Flags | OMP_IDENT_BARRIER_IMPL_SINGLE);
  } else if (Kind == OMPD_barrier) {
    Flags = static_cast<OpenMPLocationFlags>(Flags | OMP_IDENT_BARRIER_EXPL);
  } else {
    Flags = static_cast<OpenMPLocationFlags>(Flags | OMP_IDENT_BARRIER_IMPL);
  }
  // Build call __kmpc_cancel_barrier(loc, thread_id);
  // Replace __kmpc_barrier() function by __kmpc_cancel_barrier() because this
  // one provides the same functionality and adds initial support for
  // cancellation constructs introduced in OpenMP 4.0. __kmpc_cancel_barrier()
  // is provided default by the runtime library so it safe to make such
  // replacement.
  llvm::Value *Args[] = {emitUpdateLocation(CGF, Loc, Flags),
                         getThreadID(CGF, Loc)};
  CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_cancel_barrier), Args);
}

/// \brief Schedule types for 'omp for' loops (these enumerators are taken from
/// the enum sched_type in kmp.h).
enum OpenMPSchedType {
  /// \brief Lower bound for default (unordered) versions.
  OMP_sch_lower = 32,
  OMP_sch_static_chunked = 33,
  OMP_sch_static = 34,
  OMP_sch_dynamic_chunked = 35,
  OMP_sch_guided_chunked = 36,
  OMP_sch_runtime = 37,
  OMP_sch_auto = 38,
  /// \brief Lower bound for 'ordered' versions.
  OMP_ord_lower = 64,
  /// \brief Lower bound for 'nomerge' versions.
  OMP_nm_lower = 160,
};

/// \brief Map the OpenMP loop schedule to the runtime enumeration.
static OpenMPSchedType getRuntimeSchedule(OpenMPScheduleClauseKind ScheduleKind,
                                          bool Chunked) {
  switch (ScheduleKind) {
  case OMPC_SCHEDULE_static:
    return Chunked ? OMP_sch_static_chunked : OMP_sch_static;
  case OMPC_SCHEDULE_dynamic:
    return OMP_sch_dynamic_chunked;
  case OMPC_SCHEDULE_guided:
    return OMP_sch_guided_chunked;
  case OMPC_SCHEDULE_auto:
    return OMP_sch_auto;
  case OMPC_SCHEDULE_runtime:
    return OMP_sch_runtime;
  case OMPC_SCHEDULE_unknown:
    assert(!Chunked && "chunk was specified but schedule kind not known");
    return OMP_sch_static;
  }
  llvm_unreachable("Unexpected runtime schedule");
}

bool CGOpenMPRuntime::isStaticNonchunked(OpenMPScheduleClauseKind ScheduleKind,
                                         bool Chunked) const {
  auto Schedule = getRuntimeSchedule(ScheduleKind, Chunked);
  return Schedule == OMP_sch_static;
}

bool CGOpenMPRuntime::isDynamic(OpenMPScheduleClauseKind ScheduleKind) const {
  auto Schedule = getRuntimeSchedule(ScheduleKind, /* Chunked */ false);
  assert(Schedule != OMP_sch_static_chunked && "cannot be chunked here");
  return Schedule != OMP_sch_static;
}

void CGOpenMPRuntime::emitForInit(CodeGenFunction &CGF, SourceLocation Loc,
                                  OpenMPScheduleClauseKind ScheduleKind,
                                  unsigned IVSize, bool IVSigned,
                                  llvm::Value *IL, llvm::Value *LB,
                                  llvm::Value *UB, llvm::Value *ST,
                                  llvm::Value *Chunk) {
  OpenMPSchedType Schedule = getRuntimeSchedule(ScheduleKind, Chunk != nullptr);
  if (Schedule != OMP_sch_static && Schedule != OMP_sch_static_chunked) {
    // Call __kmpc_dispatch_init(
    //          ident_t *loc, kmp_int32 tid, kmp_int32 schedule,
    //          kmp_int[32|64] lower, kmp_int[32|64] upper,
    //          kmp_int[32|64] stride, kmp_int[32|64] chunk);

    // If the Chunk was not specified in the clause - use default value 1.
    if (Chunk == nullptr)
      Chunk = CGF.Builder.getIntN(IVSize, 1);
    llvm::Value *Args[] = { emitUpdateLocation(CGF, Loc, OMP_IDENT_KMPC),
                            getThreadID(CGF, Loc),
                            CGF.Builder.getInt32(Schedule), // Schedule type
                            CGF.Builder.getIntN(IVSize, 0), // Lower
                            UB,                             // Upper
                            CGF.Builder.getIntN(IVSize, 1), // Stride
                            Chunk                           // Chunk
    };
    CGF.EmitRuntimeCall(createDispatchInitFunction(IVSize, IVSigned), Args);
  } else {
    // Call __kmpc_for_static_init(
    //          ident_t *loc, kmp_int32 tid, kmp_int32 schedtype,
    //          kmp_int32 *p_lastiter, kmp_int[32|64] *p_lower,
    //          kmp_int[32|64] *p_upper, kmp_int[32|64] *p_stride,
    //          kmp_int[32|64] incr, kmp_int[32|64] chunk);
    if (Chunk == nullptr) {
      assert(Schedule == OMP_sch_static &&
             "expected static non-chunked schedule");
      // If the Chunk was not specified in the clause - use default value 1.
      Chunk = CGF.Builder.getIntN(IVSize, 1);
    } else
      assert(Schedule == OMP_sch_static_chunked &&
             "expected static chunked schedule");
    llvm::Value *Args[] = { emitUpdateLocation(CGF, Loc, OMP_IDENT_KMPC),
                            getThreadID(CGF, Loc),
                            CGF.Builder.getInt32(Schedule), // Schedule type
                            IL,                             // &isLastIter
                            LB,                             // &LB
                            UB,                             // &UB
                            ST,                             // &Stride
                            CGF.Builder.getIntN(IVSize, 1), // Incr
                            Chunk                           // Chunk
    };
    CGF.EmitRuntimeCall(createForStaticInitFunction(IVSize, IVSigned), Args);
  }
}

void CGOpenMPRuntime::emitForStaticFinish(CodeGenFunction &CGF,
                                          SourceLocation Loc) {
  // Call __kmpc_for_static_fini(ident_t *loc, kmp_int32 tid);
  llvm::Value *Args[] = {emitUpdateLocation(CGF, Loc, OMP_IDENT_KMPC),
                         getThreadID(CGF, Loc)};
  CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_for_static_fini),
                      Args);
}

void CGOpenMPRuntime::emitForOrderedDynamicIterationEnd(CodeGenFunction &CGF,
                                                        SourceLocation Loc,
                                                        unsigned IVSize,
                                                        bool IVSigned) {
  // Call __kmpc_for_dynamic_fini_(4|8)[u](ident_t *loc, kmp_int32 tid);
  llvm::Value *Args[] = {emitUpdateLocation(CGF, Loc, OMP_IDENT_KMPC),
                         getThreadID(CGF, Loc)};
  CGF.EmitRuntimeCall(createDispatchFiniFunction(IVSize, IVSigned), Args);
}

llvm::Value *CGOpenMPRuntime::emitForNext(CodeGenFunction &CGF,
                                          SourceLocation Loc, unsigned IVSize,
                                          bool IVSigned, llvm::Value *IL,
                                          llvm::Value *LB, llvm::Value *UB,
                                          llvm::Value *ST) {
  // Call __kmpc_dispatch_next(
  //          ident_t *loc, kmp_int32 tid, kmp_int32 *p_lastiter,
  //          kmp_int[32|64] *p_lower, kmp_int[32|64] *p_upper,
  //          kmp_int[32|64] *p_stride);
  llvm::Value *Args[] = {
      emitUpdateLocation(CGF, Loc, OMP_IDENT_KMPC), getThreadID(CGF, Loc),
      IL, // &isLastIter
      LB, // &Lower
      UB, // &Upper
      ST  // &Stride
  };
  llvm::Value *Call =
      CGF.EmitRuntimeCall(createDispatchNextFunction(IVSize, IVSigned), Args);
  return CGF.EmitScalarConversion(
      Call, CGF.getContext().getIntTypeForBitwidth(32, /* Signed */ true),
      CGF.getContext().BoolTy);
}

void CGOpenMPRuntime::emitNumThreadsClause(CodeGenFunction &CGF,
                                           llvm::Value *NumThreads,
                                           SourceLocation Loc) {
  // Build call __kmpc_push_num_threads(&loc, global_tid, num_threads)
  llvm::Value *Args[] = {
      emitUpdateLocation(CGF, Loc), getThreadID(CGF, Loc),
      CGF.Builder.CreateIntCast(NumThreads, CGF.Int32Ty, /*isSigned*/ true)};
  CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_push_num_threads),
                      Args);
}

void CGOpenMPRuntime::emitFlush(CodeGenFunction &CGF, ArrayRef<const Expr *>,
                                SourceLocation Loc) {
  // Build call void __kmpc_flush(ident_t *loc)
  CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_flush),
                      emitUpdateLocation(CGF, Loc));
}

namespace {
/// \brief Indexes of fields for type kmp_task_t.
enum KmpTaskTFields {
  /// \brief List of shared variables.
  KmpTaskTShareds,
  /// \brief Task routine.
  KmpTaskTRoutine,
  /// \brief Partition id for the untied tasks.
  KmpTaskTPartId,
  /// \brief Function with call of destructors for private variables.
  KmpTaskTDestructors,
  /// \brief Record with list of all private/firstprivate copies for the task
  /// directive.
  KmpTaskTPrivates,
};
} // namespace

void CGOpenMPRuntime::emitKmpRoutineEntryT(QualType KmpInt32Ty) {
  if (!KmpRoutineEntryPtrTy) {
    // Build typedef kmp_int32 (* kmp_routine_entry_t)(kmp_int32, void *); type.
    auto &C = CGM.getContext();
    QualType KmpRoutineEntryTyArgs[] = {KmpInt32Ty, C.VoidPtrTy};
    FunctionProtoType::ExtProtoInfo EPI;
    KmpRoutineEntryPtrQTy = C.getPointerType(
        C.getFunctionType(KmpInt32Ty, KmpRoutineEntryTyArgs, EPI));
    KmpRoutineEntryPtrTy = CGM.getTypes().ConvertType(KmpRoutineEntryPtrQTy);
  }
}

static void addFieldToRecordDecl(ASTContext &C, DeclContext *DC,
                                 QualType FieldTy) {
  auto *Field = FieldDecl::Create(
      C, DC, SourceLocation(), SourceLocation(), /*Id=*/nullptr, FieldTy,
      C.getTrivialTypeSourceInfo(FieldTy, SourceLocation()),
      /*BW=*/nullptr, /*Mutable=*/false, /*InitStyle=*/ICIS_NoInit);
  Field->setAccess(AS_public);
  DC->addDecl(Field);
}

namespace {
struct PrivateHelpersTy {
  PrivateHelpersTy(const VarDecl *Original, const VarDecl *PrivateCopy,
                   const VarDecl *PrivateElemInit)
      : Original(Original), PrivateCopy(PrivateCopy),
        PrivateElemInit(PrivateElemInit) {}
  const VarDecl *Original;
  const VarDecl *PrivateCopy;
  const VarDecl *PrivateElemInit;
};
typedef std::pair<CharUnits /*Align*/, PrivateHelpersTy> PrivateDataTy;
} // namespace

static RecordDecl *
createPrivatesRecordDecl(CodeGenModule &CGM,
                         const ArrayRef<PrivateDataTy> Privates) {
  if (!Privates.empty()) {
    auto &C = CGM.getContext();
    // Build struct .kmp_privates_t. {
    //         /*  private vars  */
    //       };
    auto *RD = C.buildImplicitRecord(".kmp_privates.t");
    RD->startDefinition();
    for (auto &&Pair : Privates) {
      addFieldToRecordDecl(
          C, RD, Pair.second.Original->getType().getNonReferenceType());
    }
    // TODO: add firstprivate fields.
    RD->completeDefinition();
    return RD;
  }
  return nullptr;
}

static RecordDecl *
createKmpTaskTRecordDecl(CodeGenModule &CGM, QualType KmpInt32Ty,
                         QualType KmpRoutineEntryPointerQTy,
                         const ArrayRef<PrivateDataTy> Privates) {
  auto &C = CGM.getContext();
  // Build struct kmp_task_t {
  //         void *              shareds;
  //         kmp_routine_entry_t routine;
  //         kmp_int32           part_id;
  //         kmp_routine_entry_t destructors;
  //         /*  private vars  */
  //       };
  auto *RD = C.buildImplicitRecord("kmp_task_t");
  RD->startDefinition();
  addFieldToRecordDecl(C, RD, C.VoidPtrTy);
  addFieldToRecordDecl(C, RD, KmpRoutineEntryPointerQTy);
  addFieldToRecordDecl(C, RD, KmpInt32Ty);
  addFieldToRecordDecl(C, RD, KmpRoutineEntryPointerQTy);
  if (auto *PrivateRD = createPrivatesRecordDecl(CGM, Privates)) {
    addFieldToRecordDecl(C, RD, C.getRecordType(PrivateRD));
  }
  RD->completeDefinition();
  return RD;
}

/// \brief Emit a proxy function which accepts kmp_task_t as the second
/// argument.
/// \code
/// kmp_int32 .omp_task_entry.(kmp_int32 gtid, kmp_task_t *tt) {
///   TaskFunction(gtid, tt->part_id, tt->shareds);
///   return 0;
/// }
/// \endcode
static llvm::Value *
emitProxyTaskFunction(CodeGenModule &CGM, SourceLocation Loc,
                      QualType KmpInt32Ty, QualType KmpTaskTPtrQTy,
                      QualType SharedsPtrTy, llvm::Value *TaskFunction,
                      llvm::Type *KmpTaskTTy) {
  auto &C = CGM.getContext();
  FunctionArgList Args;
  ImplicitParamDecl GtidArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr, KmpInt32Ty);
  ImplicitParamDecl TaskTypeArg(C, /*DC=*/nullptr, Loc,
                                /*Id=*/nullptr, KmpTaskTPtrQTy);
  Args.push_back(&GtidArg);
  Args.push_back(&TaskTypeArg);
  FunctionType::ExtInfo Info;
  auto &TaskEntryFnInfo =
      CGM.getTypes().arrangeFreeFunctionDeclaration(KmpInt32Ty, Args, Info,
                                                    /*isVariadic=*/false);
  auto *TaskEntryTy = CGM.getTypes().GetFunctionType(TaskEntryFnInfo);
  auto *TaskEntry =
      llvm::Function::Create(TaskEntryTy, llvm::GlobalValue::InternalLinkage,
                             ".omp_task_entry.", &CGM.getModule());
  CGM.SetLLVMFunctionAttributes(/*D=*/nullptr, TaskEntryFnInfo, TaskEntry);
  CodeGenFunction CGF(CGM);
  CGF.disableDebugInfo();
  CGF.StartFunction(GlobalDecl(), KmpInt32Ty, TaskEntry, TaskEntryFnInfo, Args);

  // TaskFunction(gtid, tt->part_id, tt->shareds);
  auto *GtidParam = CGF.EmitLoadOfScalar(
      CGF.GetAddrOfLocalVar(&GtidArg), /*Volatile=*/false,
      C.getTypeAlignInChars(KmpInt32Ty).getQuantity(), KmpInt32Ty, Loc);
  auto TaskTypeArgAddr = CGF.EmitLoadOfScalar(
      CGF.GetAddrOfLocalVar(&TaskTypeArg), /*Volatile=*/false,
      CGM.PointerAlignInBytes, KmpTaskTPtrQTy, Loc);
  auto *PartidPtr = CGF.Builder.CreateStructGEP(KmpTaskTTy, TaskTypeArgAddr,
                                                /*Idx=*/KmpTaskTPartId);
  auto *PartidParam = CGF.EmitLoadOfScalar(
      PartidPtr, /*Volatile=*/false,
      C.getTypeAlignInChars(KmpInt32Ty).getQuantity(), KmpInt32Ty, Loc);
  auto *SharedsPtr = CGF.Builder.CreateStructGEP(KmpTaskTTy, TaskTypeArgAddr,
                                                 /*Idx=*/KmpTaskTShareds);
  auto *SharedsParam = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
      CGF.EmitLoadOfScalar(SharedsPtr, /*Volatile=*/false,
                           CGM.PointerAlignInBytes, C.VoidPtrTy, Loc),
      CGF.ConvertTypeForMem(SharedsPtrTy));

  llvm::Value *CallArgs[] = {GtidParam, PartidParam, SharedsParam};
  CGF.EmitCallOrInvoke(TaskFunction, CallArgs);
  CGF.EmitStoreThroughLValue(
      RValue::get(CGF.Builder.getInt32(/*C=*/0)),
      CGF.MakeNaturalAlignAddrLValue(CGF.ReturnValue, KmpInt32Ty));
  CGF.FinishFunction();
  return TaskEntry;
}

static llvm::Value *
emitDestructorsFunction(CodeGenModule &CGM, SourceLocation Loc,
                        QualType KmpInt32Ty, QualType KmpTaskTPtrQTy,
                        QualType KmpTaskQTy, RecordDecl *KmpTaskQTyRD) {
  auto &C = CGM.getContext();
  FunctionArgList Args;
  ImplicitParamDecl GtidArg(C, /*DC=*/nullptr, Loc, /*Id=*/nullptr, KmpInt32Ty);
  ImplicitParamDecl TaskTypeArg(C, /*DC=*/nullptr, Loc,
                                /*Id=*/nullptr, KmpTaskTPtrQTy);
  Args.push_back(&GtidArg);
  Args.push_back(&TaskTypeArg);
  FunctionType::ExtInfo Info;
  auto &DestructorFnInfo =
      CGM.getTypes().arrangeFreeFunctionDeclaration(KmpInt32Ty, Args, Info,
                                                    /*isVariadic=*/false);
  auto *DestructorFnTy = CGM.getTypes().GetFunctionType(DestructorFnInfo);
  auto *DestructorFn =
      llvm::Function::Create(DestructorFnTy, llvm::GlobalValue::InternalLinkage,
                             ".omp_task_destructor.", &CGM.getModule());
  CGM.SetLLVMFunctionAttributes(/*D=*/nullptr, DestructorFnInfo, DestructorFn);
  CodeGenFunction CGF(CGM);
  CGF.disableDebugInfo();
  CGF.StartFunction(GlobalDecl(), KmpInt32Ty, DestructorFn, DestructorFnInfo,
                    Args);

  auto *TaskTypeArgAddr = CGF.EmitLoadOfScalar(
      CGF.GetAddrOfLocalVar(&TaskTypeArg), /*Volatile=*/false,
      CGM.PointerAlignInBytes, KmpTaskTPtrQTy, Loc);
  LValue Base = CGF.MakeNaturalAlignAddrLValue(TaskTypeArgAddr, KmpTaskQTy);
  auto FI = std::next(KmpTaskQTyRD->field_begin(), KmpTaskTPrivates);
  Base = CGF.EmitLValueForField(Base, *FI);
  for (auto *Field :
       cast<RecordDecl>(FI->getType()->getAsTagDecl())->fields()) {
    if (auto DtorKind = Field->getType().isDestructedType()) {
      auto FieldLValue = CGF.EmitLValueForField(Base, Field);
      CGF.pushDestroy(DtorKind, FieldLValue.getAddress(), Field->getType());
    }
  }
  CGF.FinishFunction();
  return DestructorFn;
}

static int array_pod_sort_comparator(const PrivateDataTy *P1,
                                     const PrivateDataTy *P2) {
  return P1->first < P2->first ? 1 : (P2->first < P1->first ? -1 : 0);
}

void CGOpenMPRuntime::emitTaskCall(
    CodeGenFunction &CGF, SourceLocation Loc, const OMPExecutableDirective &D,
    bool Tied, llvm::PointerIntPair<llvm::Value *, 1, bool> Final,
    llvm::Value *TaskFunction, QualType SharedsTy, llvm::Value *Shareds,
    const Expr *IfCond, const ArrayRef<const Expr *> PrivateVars,
    const ArrayRef<const Expr *> PrivateCopies,
    const ArrayRef<const Expr *> FirstprivateVars,
    const ArrayRef<const Expr *> FirstprivateCopies,
    const ArrayRef<const Expr *> FirstprivateInits) {
  auto &C = CGM.getContext();
  llvm::SmallVector<PrivateDataTy, 8> Privates;
  // Aggeregate privates and sort them by the alignment.
  auto I = PrivateCopies.begin();
  for (auto *E : PrivateVars) {
    auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
    Privates.push_back(std::make_pair(
        C.getTypeAlignInChars(VD->getType()),
        PrivateHelpersTy(VD, cast<VarDecl>(cast<DeclRefExpr>(*I)->getDecl()),
                         /*PrivateElemInit=*/nullptr)));
    ++I;
  }
  I = FirstprivateCopies.begin();
  auto IElemInitRef = FirstprivateInits.begin();
  for (auto *E : FirstprivateVars) {
    auto *VD = cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
    Privates.push_back(std::make_pair(
        C.getTypeAlignInChars(VD->getType()),
        PrivateHelpersTy(
            VD, cast<VarDecl>(cast<DeclRefExpr>(*I)->getDecl()),
            cast<VarDecl>(cast<DeclRefExpr>(*IElemInitRef)->getDecl()))));
    ++I, ++IElemInitRef;
  }
  llvm::array_pod_sort(Privates.begin(), Privates.end(),
                       array_pod_sort_comparator);
  auto KmpInt32Ty = C.getIntTypeForBitwidth(/*DestWidth=*/32, /*Signed=*/1);
  // Build type kmp_routine_entry_t (if not built yet).
  emitKmpRoutineEntryT(KmpInt32Ty);
  // Build particular struct kmp_task_t for the given task.
  auto *KmpTaskQTyRD = createKmpTaskTRecordDecl(
      CGM, KmpInt32Ty, KmpRoutineEntryPtrQTy, Privates);
  auto KmpTaskQTy = C.getRecordType(KmpTaskQTyRD);
  QualType KmpTaskTPtrQTy = C.getPointerType(KmpTaskQTy);
  auto *KmpTaskTTy = CGF.ConvertType(KmpTaskQTy);
  auto *KmpTaskTPtrTy = KmpTaskTTy->getPointerTo();
  auto KmpTaskTySize = CGM.getSize(C.getTypeSizeInChars(KmpTaskQTy));
  QualType SharedsPtrTy = C.getPointerType(SharedsTy);

  // Build a proxy function kmp_int32 .omp_task_entry.(kmp_int32 gtid,
  // kmp_task_t *tt);
  auto *TaskEntry =
      emitProxyTaskFunction(CGM, Loc, KmpInt32Ty, KmpTaskTPtrQTy, SharedsPtrTy,
                            TaskFunction, KmpTaskTTy);

  // Build call kmp_task_t * __kmpc_omp_task_alloc(ident_t *, kmp_int32 gtid,
  // kmp_int32 flags, size_t sizeof_kmp_task_t, size_t sizeof_shareds,
  // kmp_routine_entry_t *task_entry);
  // Task flags. Format is taken from
  // http://llvm.org/svn/llvm-project/openmp/trunk/runtime/src/kmp.h,
  // description of kmp_tasking_flags struct.
  const unsigned TiedFlag = 0x1;
  const unsigned FinalFlag = 0x2;
  unsigned Flags = Tied ? TiedFlag : 0;
  auto *TaskFlags =
      Final.getPointer()
          ? CGF.Builder.CreateSelect(Final.getPointer(),
                                     CGF.Builder.getInt32(FinalFlag),
                                     CGF.Builder.getInt32(/*C=*/0))
          : CGF.Builder.getInt32(Final.getInt() ? FinalFlag : 0);
  TaskFlags = CGF.Builder.CreateOr(TaskFlags, CGF.Builder.getInt32(Flags));
  auto SharedsSize = C.getTypeSizeInChars(SharedsTy);
  llvm::Value *AllocArgs[] = {emitUpdateLocation(CGF, Loc),
                              getThreadID(CGF, Loc), TaskFlags, KmpTaskTySize,
                              CGM.getSize(SharedsSize),
                              CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
                                  TaskEntry, KmpRoutineEntryPtrTy)};
  auto *NewTask = CGF.EmitRuntimeCall(
      createRuntimeFunction(OMPRTL__kmpc_omp_task_alloc), AllocArgs);
  auto *NewTaskNewTaskTTy =
      CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(NewTask, KmpTaskTPtrTy);
  // Fill the data in the resulting kmp_task_t record.
  // Copy shareds if there are any.
  auto *KmpTaskSharedsPtr = CGF.EmitLoadOfScalar(
      CGF.Builder.CreateStructGEP(KmpTaskTTy, NewTaskNewTaskTTy,
                                  /*Idx=*/KmpTaskTShareds),
      /*Volatile=*/false, CGM.PointerAlignInBytes, SharedsPtrTy, Loc);
  if (!SharedsTy->getAsStructureType()->getDecl()->field_empty())
    CGF.EmitAggregateCopy(KmpTaskSharedsPtr, Shareds, SharedsTy);
  // Emit initial values for private copies (if any).
  bool NeedsCleanup = false;
  if (!Privates.empty()) {
    LValue Base = CGF.MakeNaturalAlignAddrLValue(NewTaskNewTaskTTy, KmpTaskQTy);
    auto FI = std::next(KmpTaskQTyRD->field_begin(), KmpTaskTPrivates);
    Base = CGF.EmitLValueForField(Base, *FI);
    FI = cast<RecordDecl>(FI->getType()->getAsTagDecl())->field_begin();
    LValue SharedsBase = CGF.MakeNaturalAlignAddrLValue(
        CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
            KmpTaskSharedsPtr, CGF.ConvertTypeForMem(SharedsPtrTy)),
        SharedsTy);
    CodeGenFunction::CGCapturedStmtInfo CapturesInfo(
        cast<CapturedStmt>(*D.getAssociatedStmt()));
    for (auto &&Pair : Privates) {
      auto *VD = Pair.second.PrivateCopy;
      auto *Init = VD->getAnyInitializer();
      LValue PrivateLValue = CGF.EmitLValueForField(Base, *FI);
      if (Init) {
        if (auto *Elem = Pair.second.PrivateElemInit) {
          auto *OriginalVD = Pair.second.Original;
          auto *SharedField = CapturesInfo.lookup(OriginalVD);
          auto SharedRefLValue =
              CGF.EmitLValueForField(SharedsBase, SharedField);
          if (OriginalVD->getType()->isArrayType()) {
            // Initialize firstprivate array.
            if (!isa<CXXConstructExpr>(Init) ||
                CGF.isTrivialInitializer(Init)) {
              // Perform simple memcpy.
              CGF.EmitAggregateAssign(PrivateLValue.getAddress(),
                                      SharedRefLValue.getAddress(),
                                      OriginalVD->getType());
            } else {
              // Initialize firstprivate array using element-by-element
              // intialization.
              CGF.EmitOMPAggregateAssign(
                  PrivateLValue.getAddress(), SharedRefLValue.getAddress(),
                  OriginalVD->getType(),
                  [&CGF, Elem, Init, &CapturesInfo](llvm::Value *DestElement,
                                                    llvm::Value *SrcElement) {
                    // Clean up any temporaries needed by the initialization.
                    CodeGenFunction::OMPPrivateScope InitScope(CGF);
                    InitScope.addPrivate(Elem, [SrcElement]() -> llvm::Value *{
                      return SrcElement;
                    });
                    (void)InitScope.Privatize();
                    // Emit initialization for single element.
                    auto *OldCapturedStmtInfo = CGF.CapturedStmtInfo;
                    CGF.CapturedStmtInfo = &CapturesInfo;
                    CGF.EmitAnyExprToMem(Init, DestElement,
                                         Init->getType().getQualifiers(),
                                         /*IsInitializer=*/false);
                    CGF.CapturedStmtInfo = OldCapturedStmtInfo;
                  });
            }
          } else {
            CodeGenFunction::OMPPrivateScope InitScope(CGF);
            InitScope.addPrivate(Elem, [SharedRefLValue]() -> llvm::Value *{
              return SharedRefLValue.getAddress();
            });
            (void)InitScope.Privatize();
            auto *OldCapturedStmtInfo = CGF.CapturedStmtInfo;
            CGF.CapturedStmtInfo = &CapturesInfo;
            CGF.EmitExprAsInit(Init, VD, PrivateLValue,
                               /*capturedByInit=*/false);
            CGF.CapturedStmtInfo = OldCapturedStmtInfo;
          }
        } else {
          CGF.EmitExprAsInit(Init, VD, PrivateLValue, /*capturedByInit=*/false);
        }
      }
      NeedsCleanup = NeedsCleanup || FI->getType().isDestructedType();
      // Copy addresses of privates to corresponding references in the list of
      // captured variables.
      //   ...
      //   tt->shareds.var_addr = &tt->privates.private_var;
      //   ...
      auto *OriginalVD = Pair.second.Original;
      auto *SharedField = CapturesInfo.lookup(OriginalVD);
      auto SharedRefLValue =
          CGF.EmitLValueForFieldInitialization(SharedsBase, SharedField);
      CGF.EmitStoreThroughLValue(RValue::get(PrivateLValue.getAddress()),
                                 SharedRefLValue);
      ++FI, ++I;
    }
  }
  // Provide pointer to function with destructors for privates.
  llvm::Value *DestructorFn =
      NeedsCleanup
          ? emitDestructorsFunction(CGM, Loc, KmpInt32Ty, KmpTaskTPtrQTy,
                                    KmpTaskQTy, KmpTaskQTyRD)
          : llvm::ConstantPointerNull::get(
                cast<llvm::PointerType>(KmpRoutineEntryPtrTy));
  CGF.Builder.CreateAlignedStore(
      CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(DestructorFn,
                                                      KmpRoutineEntryPtrTy),
      CGF.Builder.CreateStructGEP(KmpTaskTTy, NewTaskNewTaskTTy,
                                  /*Idx=*/KmpTaskTDestructors),
      CGM.PointerAlignInBytes);
  // NOTE: routine and part_id fields are intialized by __kmpc_omp_task_alloc()
  // libcall.
  // Build kmp_int32 __kmpc_omp_task(ident_t *, kmp_int32 gtid, kmp_task_t
  // *new_task);
  auto *ThreadID = getThreadID(CGF, Loc);
  llvm::Value *TaskArgs[] = {emitUpdateLocation(CGF, Loc), ThreadID, NewTask};
  auto &&ThenCodeGen = [this, &TaskArgs](CodeGenFunction &CGF) {
    // TODO: add check for untied tasks.
    CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_omp_task), TaskArgs);
  };
  auto &&ElseCodeGen =
      [this, &TaskArgs, ThreadID, NewTaskNewTaskTTy, TaskEntry](
          CodeGenFunction &CGF) {
        CodeGenFunction::RunCleanupsScope LocalScope(CGF);
        CGF.EmitRuntimeCall(
            createRuntimeFunction(OMPRTL__kmpc_omp_task_begin_if0), TaskArgs);
        // Build void __kmpc_omp_task_complete_if0(ident_t *, kmp_int32 gtid,
        // kmp_task_t *new_task);
        CGF.EHStack.pushCleanup<CallEndCleanup>(
            NormalAndEHCleanup,
            createRuntimeFunction(OMPRTL__kmpc_omp_task_complete_if0),
            llvm::makeArrayRef(TaskArgs));

        // Call proxy_task_entry(gtid, new_task);
        llvm::Value *OutlinedFnArgs[] = {ThreadID, NewTaskNewTaskTTy};
        CGF.EmitCallOrInvoke(TaskEntry, OutlinedFnArgs);
      };
  if (IfCond) {
    emitOMPIfClause(CGF, IfCond, ThenCodeGen, ElseCodeGen);
  } else {
    CodeGenFunction::RunCleanupsScope Scope(CGF);
    ThenCodeGen(CGF);
  }
}

static llvm::Value *emitReductionFunction(CodeGenModule &CGM,
                                          llvm::Type *ArgsType,
                                          ArrayRef<const Expr *> LHSExprs,
                                          ArrayRef<const Expr *> RHSExprs,
                                          ArrayRef<const Expr *> ReductionOps) {
  auto &C = CGM.getContext();

  // void reduction_func(void *LHSArg, void *RHSArg);
  FunctionArgList Args;
  ImplicitParamDecl LHSArg(C, /*DC=*/nullptr, SourceLocation(), /*Id=*/nullptr,
                           C.VoidPtrTy);
  ImplicitParamDecl RHSArg(C, /*DC=*/nullptr, SourceLocation(), /*Id=*/nullptr,
                           C.VoidPtrTy);
  Args.push_back(&LHSArg);
  Args.push_back(&RHSArg);
  FunctionType::ExtInfo EI;
  auto &CGFI = CGM.getTypes().arrangeFreeFunctionDeclaration(
      C.VoidTy, Args, EI, /*isVariadic=*/false);
  auto *Fn = llvm::Function::Create(
      CGM.getTypes().GetFunctionType(CGFI), llvm::GlobalValue::InternalLinkage,
      ".omp.reduction.reduction_func", &CGM.getModule());
  CGM.SetLLVMFunctionAttributes(/*D=*/nullptr, CGFI, Fn);
  CodeGenFunction CGF(CGM);
  CGF.StartFunction(GlobalDecl(), C.VoidTy, Fn, CGFI, Args);

  // Dst = (void*[n])(LHSArg);
  // Src = (void*[n])(RHSArg);
  auto *LHS = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
      CGF.Builder.CreateAlignedLoad(CGF.GetAddrOfLocalVar(&LHSArg),
                                    CGF.PointerAlignInBytes),
      ArgsType);
  auto *RHS = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
      CGF.Builder.CreateAlignedLoad(CGF.GetAddrOfLocalVar(&RHSArg),
                                    CGF.PointerAlignInBytes),
      ArgsType);

  //  ...
  //  *(Type<i>*)lhs[i] = RedOp<i>(*(Type<i>*)lhs[i], *(Type<i>*)rhs[i]);
  //  ...
  CodeGenFunction::OMPPrivateScope Scope(CGF);
  for (unsigned I = 0, E = ReductionOps.size(); I < E; ++I) {
    Scope.addPrivate(
        cast<VarDecl>(cast<DeclRefExpr>(RHSExprs[I])->getDecl()),
        [&]() -> llvm::Value *{
          return CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
              CGF.Builder.CreateAlignedLoad(
                  CGF.Builder.CreateStructGEP(/*Ty=*/nullptr, RHS, I),
                  CGM.PointerAlignInBytes),
              CGF.ConvertTypeForMem(C.getPointerType(RHSExprs[I]->getType())));
        });
    Scope.addPrivate(
        cast<VarDecl>(cast<DeclRefExpr>(LHSExprs[I])->getDecl()),
        [&]() -> llvm::Value *{
          return CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
              CGF.Builder.CreateAlignedLoad(
                  CGF.Builder.CreateStructGEP(/*Ty=*/nullptr, LHS, I),
                  CGM.PointerAlignInBytes),
              CGF.ConvertTypeForMem(C.getPointerType(LHSExprs[I]->getType())));
        });
  }
  Scope.Privatize();
  for (auto *E : ReductionOps) {
    CGF.EmitIgnoredExpr(E);
  }
  Scope.ForceCleanup();
  CGF.FinishFunction();
  return Fn;
}

void CGOpenMPRuntime::emitReduction(CodeGenFunction &CGF, SourceLocation Loc,
                                    ArrayRef<const Expr *> LHSExprs,
                                    ArrayRef<const Expr *> RHSExprs,
                                    ArrayRef<const Expr *> ReductionOps,
                                    bool WithNowait) {
  // Next code should be emitted for reduction:
  //
  // static kmp_critical_name lock = { 0 };
  //
  // void reduce_func(void *lhs[<n>], void *rhs[<n>]) {
  //  *(Type0*)lhs[0] = ReductionOperation0(*(Type0*)lhs[0], *(Type0*)rhs[0]);
  //  ...
  //  *(Type<n>-1*)lhs[<n>-1] = ReductionOperation<n>-1(*(Type<n>-1*)lhs[<n>-1],
  //  *(Type<n>-1*)rhs[<n>-1]);
  // }
  //
  // ...
  // void *RedList[<n>] = {&<RHSExprs>[0], ..., &<RHSExprs>[<n>-1]};
  // switch (__kmpc_reduce{_nowait}(<loc>, <gtid>, <n>, sizeof(RedList),
  // RedList, reduce_func, &<lock>)) {
  // case 1:
  //  ...
  //  <LHSExprs>[i] = RedOp<i>(*<LHSExprs>[i], *<RHSExprs>[i]);
  //  ...
  // __kmpc_end_reduce{_nowait}(<loc>, <gtid>, &<lock>);
  // break;
  // case 2:
  //  ...
  //  Atomic(<LHSExprs>[i] = RedOp<i>(*<LHSExprs>[i], *<RHSExprs>[i]));
  //  ...
  // break;
  // default:;
  // }

  auto &C = CGM.getContext();

  // 1. Build a list of reduction variables.
  // void *RedList[<n>] = {<ReductionVars>[0], ..., <ReductionVars>[<n>-1]};
  llvm::APInt ArraySize(/*unsigned int numBits=*/32, RHSExprs.size());
  QualType ReductionArrayTy =
      C.getConstantArrayType(C.VoidPtrTy, ArraySize, ArrayType::Normal,
                             /*IndexTypeQuals=*/0);
  auto *ReductionList =
      CGF.CreateMemTemp(ReductionArrayTy, ".omp.reduction.red_list");
  for (unsigned I = 0, E = RHSExprs.size(); I < E; ++I) {
    auto *Elem = CGF.Builder.CreateStructGEP(/*Ty=*/nullptr, ReductionList, I);
    CGF.Builder.CreateAlignedStore(
        CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
            CGF.EmitLValue(RHSExprs[I]).getAddress(), CGF.VoidPtrTy),
        Elem, CGM.PointerAlignInBytes);
  }

  // 2. Emit reduce_func().
  auto *ReductionFn = emitReductionFunction(
      CGM, CGF.ConvertTypeForMem(ReductionArrayTy)->getPointerTo(), LHSExprs,
      RHSExprs, ReductionOps);

  // 3. Create static kmp_critical_name lock = { 0 };
  auto *Lock = getCriticalRegionLock(".reduction");

  // 4. Build res = __kmpc_reduce{_nowait}(<loc>, <gtid>, <n>, sizeof(RedList),
  // RedList, reduce_func, &<lock>);
  auto *IdentTLoc = emitUpdateLocation(
      CGF, Loc,
      static_cast<OpenMPLocationFlags>(OMP_IDENT_KMPC | OMP_ATOMIC_REDUCE));
  auto *ThreadId = getThreadID(CGF, Loc);
  auto *ReductionArrayTySize = llvm::ConstantInt::get(
      CGM.SizeTy, C.getTypeSizeInChars(ReductionArrayTy).getQuantity());
  auto *RL = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(ReductionList,
                                                             CGF.VoidPtrTy);
  llvm::Value *Args[] = {
      IdentTLoc,                             // ident_t *<loc>
      ThreadId,                              // i32 <gtid>
      CGF.Builder.getInt32(RHSExprs.size()), // i32 <n>
      ReductionArrayTySize,                  // size_type sizeof(RedList)
      RL,                                    // void *RedList
      ReductionFn, // void (*) (void *, void *) <reduce_func>
      Lock         // kmp_critical_name *&<lock>
  };
  auto Res = CGF.EmitRuntimeCall(
      createRuntimeFunction(WithNowait ? OMPRTL__kmpc_reduce_nowait
                                       : OMPRTL__kmpc_reduce),
      Args);

  // 5. Build switch(res)
  auto *DefaultBB = CGF.createBasicBlock(".omp.reduction.default");
  auto *SwInst = CGF.Builder.CreateSwitch(Res, DefaultBB, /*NumCases=*/2);

  // 6. Build case 1:
  //  ...
  //  <LHSExprs>[i] = RedOp<i>(*<LHSExprs>[i], *<RHSExprs>[i]);
  //  ...
  // __kmpc_end_reduce{_nowait}(<loc>, <gtid>, &<lock>);
  // break;
  auto *Case1BB = CGF.createBasicBlock(".omp.reduction.case1");
  SwInst->addCase(CGF.Builder.getInt32(1), Case1BB);
  CGF.EmitBlock(Case1BB);

  {
    CodeGenFunction::RunCleanupsScope Scope(CGF);
    // Add emission of __kmpc_end_reduce{_nowait}(<loc>, <gtid>, &<lock>);
    llvm::Value *EndArgs[] = {
        IdentTLoc, // ident_t *<loc>
        ThreadId,  // i32 <gtid>
        Lock       // kmp_critical_name *&<lock>
    };
    CGF.EHStack.pushCleanup<CallEndCleanup>(
        NormalAndEHCleanup,
        createRuntimeFunction(WithNowait ? OMPRTL__kmpc_end_reduce_nowait
                                         : OMPRTL__kmpc_end_reduce),
        llvm::makeArrayRef(EndArgs));
    for (auto *E : ReductionOps) {
      CGF.EmitIgnoredExpr(E);
    }
  }

  CGF.EmitBranch(DefaultBB);

  // 7. Build case 2:
  //  ...
  //  Atomic(<LHSExprs>[i] = RedOp<i>(*<LHSExprs>[i], *<RHSExprs>[i]));
  //  ...
  // break;
  auto *Case2BB = CGF.createBasicBlock(".omp.reduction.case2");
  SwInst->addCase(CGF.Builder.getInt32(2), Case2BB);
  CGF.EmitBlock(Case2BB);

  {
    CodeGenFunction::RunCleanupsScope Scope(CGF);
    auto I = LHSExprs.begin();
    for (auto *E : ReductionOps) {
      const Expr *XExpr = nullptr;
      const Expr *EExpr = nullptr;
      const Expr *UpExpr = nullptr;
      BinaryOperatorKind BO = BO_Comma;
      // Try to emit update expression as a simple atomic.
      if (auto *ACO = dyn_cast<AbstractConditionalOperator>(E)) {
        // If this is a conditional operator, analyze it's condition for
        // min/max reduction operator.
        E = ACO->getCond();
      }
      if (auto *BO = dyn_cast<BinaryOperator>(E)) {
        if (BO->getOpcode() == BO_Assign) {
          XExpr = BO->getLHS();
          UpExpr = BO->getRHS();
        }
      }
      // Analyze RHS part of the whole expression.
      if (UpExpr) {
        if (auto *BORHS =
                dyn_cast<BinaryOperator>(UpExpr->IgnoreParenImpCasts())) {
          EExpr = BORHS->getRHS();
          BO = BORHS->getOpcode();
        }
      }
      if (XExpr) {
        auto *VD = cast<VarDecl>(cast<DeclRefExpr>(*I)->getDecl());
        LValue X = CGF.EmitLValue(XExpr);
        RValue E;
        if (EExpr)
          E = CGF.EmitAnyExpr(EExpr);
        CGF.EmitOMPAtomicSimpleUpdateExpr(
            X, E, BO, /*IsXLHSInRHSPart=*/true, llvm::Monotonic, Loc,
            [&CGF, UpExpr, VD](RValue XRValue) {
              CodeGenFunction::OMPPrivateScope PrivateScope(CGF);
              PrivateScope.addPrivate(
                  VD, [&CGF, VD, XRValue]() -> llvm::Value *{
                    auto *LHSTemp = CGF.CreateMemTemp(VD->getType());
                    CGF.EmitStoreThroughLValue(
                        XRValue,
                        CGF.MakeNaturalAlignAddrLValue(LHSTemp, VD->getType()));
                    return LHSTemp;
                  });
              (void)PrivateScope.Privatize();
              return CGF.EmitAnyExpr(UpExpr);
            });
      } else {
        // Emit as a critical region.
        emitCriticalRegion(CGF, ".atomic_reduction", [E](CodeGenFunction &CGF) {
          CGF.EmitIgnoredExpr(E);
        }, Loc);
      }
      ++I;
    }
  }

  CGF.EmitBranch(DefaultBB);
  CGF.EmitBlock(DefaultBB, /*IsFinished=*/true);
}

void CGOpenMPRuntime::emitTaskwaitCall(CodeGenFunction &CGF,
                                       SourceLocation Loc) {
  // Build call kmp_int32 __kmpc_omp_taskwait(ident_t *loc, kmp_int32
  // global_tid);
  llvm::Value *Args[] = {emitUpdateLocation(CGF, Loc), getThreadID(CGF, Loc)};
  // Ignore return result until untied tasks are supported.
  CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__kmpc_omp_taskwait), Args);
}

void CGOpenMPRuntime::emitInlinedDirective(CodeGenFunction &CGF,
                                           const RegionCodeGenTy &CodeGen) {
  InlinedOpenMPRegionRAII Region(CGF, CodeGen);
  CGF.CapturedStmtInfo->EmitBody(CGF, /*S=*/nullptr);
}