Simplifying memory globalization from the front end to move optimizations to the middle end.

[josemonsalve2]

Summary

Memory globalization was fully implemented in the front end. There are three runtime
functions in Libomptarget:

• __kmpc_data_sharing_push_stack
• __kmpc_data_sharing_coalesced_push_stack
• __kmpc_data_sharing_pop_stack

The front end performed a scape analysis and created a record declare with all the stack
variables. Then, based on the context (isTTD and other parameters) it would create a push
for the size of the record, or for that size multiplied by the WARP (to globalize for the
whole WARP.

This PR removes the record creation, and it simplifies the front end to be a simple runtime
call that will be later on optimized in the middle end. The middle end will be able to
determine the stack variables that do scape, and those that do not, as well as the
approrpiate merging of different globalized variables

[jdoerfert]

Let's start by adding an updated test to this so we can see how the result looks.

[josemonsalve2]

Removing globalized record for parallel regions

When globalization occurs in parallel regions, a record was crerated that is not necessary anymore.
This is expected to be done in the back end.

[josemonsalve2]

I'm working on the other tests right now.

[josemonsalve2]

Modifying 3 more tests to reflect changes in this patch

[josemonsalve2]

This has been completed by @jhuber6 in D97680

clang/lib/CodeGen/CGOpenMPRuntimeGPU.h

private:
   /// and controls the parameters which are passed to this function.
   /// The wrapper ensures that the outlined function is called
   /// with the correct arguments when data is shared.
   llvm::Function *createParallelDataSharingWrapper(
       llvm::Function *OutlinedParallelFn, const OMPExecutableDirective &D);
 
   /// The data for the single globalized variable.
   struct MappedVarData {
-    /// Corresponding field in the global record.
-    const FieldDecl *FD = nullptr;
     /// Corresponding address.
     Address PrivateAddr = Address::invalid();
+    llvm::Value *globalizedVal;
     /// true, if only one element is required (for latprivates in SPMD mode),
     /// false, if need to create based on the warp-size.
     bool IsOnePerTeam = false;
     MappedVarData() = delete;
-    MappedVarData(const FieldDecl *FD, bool IsOnePerTeam = false)
-        : FD(FD), IsOnePerTeam(IsOnePerTeam) {}
+    MappedVarData(bool IsOnePerTeam = false) : IsOnePerTeam(IsOnePerTeam) {}
   };
   /// The map of local variables to their addresses in the global memory.
   using DeclToAddrMapTy = llvm::MapVector<const Decl *, MappedVarData>;
   /// Set of the parameters passed by value escaping OpenMP context.
   using EscapedParamsTy = llvm::SmallPtrSet<const Decl *, 4>;
   struct FunctionData {
     DeclToAddrMapTy LocalVarData;
-    llvm::Optional<DeclToAddrMapTy> SecondaryLocalVarData = llvm::None;
     EscapedParamsTy EscapedParameters;
     llvm::SmallVector<const ValueDecl*, 4> EscapedVariableLengthDecls;
     llvm::SmallVector<llvm::Value *, 4> EscapedVariableLengthDeclsAddrs;
-    const RecordDecl *GlobalRecord = nullptr;
-    llvm::Optional<const RecordDecl *> SecondaryGlobalRecord = llvm::None;
-    llvm::Value *GlobalRecordAddr = nullptr;
     llvm::Value *IsInSPMDModeFlag = nullptr;
     std::unique_ptr<CodeGenFunction::OMPMapVars> MappedParams;
   };
   /// Maps the function to the list of the globalized variables with their
   /// addresses.
   llvm::SmallDenseMap<llvm::Function *, FunctionData> FunctionGlobalizedDecls;
   /// List of records for the globalized variables in target/teams/distribute
   /// contexts. Inner records are going to be joined into the single record,

clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp

 
 /// Get the list of variables that can escape their declaration context.
 class CheckVarsEscapingDeclContext final
     : public ConstStmtVisitor<CheckVarsEscapingDeclContext> {
   CodeGenFunction &CGF;
   llvm::SetVector<const ValueDecl *> EscapedDecls;
   llvm::SetVector<const ValueDecl *> EscapedVariableLengthDecls;
   llvm::SmallPtrSet<const Decl *, 4> EscapedParameters;
-  RecordDecl *GlobalizedRD = nullptr;
   llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *> MappedDeclsFields;
   bool AllEscaped = false;
   bool IsForCombinedParallelRegion = false;
 
   void markAsEscaped(const ValueDecl *VD) {
     // Do not globalize declare target variables.
     if (!isa<VarDecl>(VD) ||
         OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD))
for (const CapturedStmt::Capture &C : S->captures()) {
         markAsEscaped(VD);
         if (isa<OMPCapturedExprDecl>(VD))
           VisitValueDecl(VD);
         IsForCombinedParallelRegion = SavedIsForCombinedParallelRegion;
       }
     }
   }
 
-  void buildRecordForGlobalizedVars(bool IsInTTDRegion) {
-    assert(!GlobalizedRD &&
-           "Record for globalized variables is built already.");
-    ArrayRef<const ValueDecl *> EscapedDeclsForParallel, EscapedDeclsForTeams;
-    unsigned WarpSize = CGF.getTarget().getGridValue(llvm::omp::GV_Warp_Size);
-    if (IsInTTDRegion)
-      EscapedDeclsForTeams = EscapedDecls.getArrayRef();
-    else
-      EscapedDeclsForParallel = EscapedDecls.getArrayRef();
-    GlobalizedRD = ::buildRecordForGlobalizedVars(
-        CGF.getContext(), EscapedDeclsForParallel, EscapedDeclsForTeams,
-        MappedDeclsFields, WarpSize);
-  }
 
 public:
   CheckVarsEscapingDeclContext(CodeGenFunction &CGF,
                                ArrayRef<const ValueDecl *> TeamsReductions)
       : CGF(CGF), EscapedDecls(TeamsReductions.begin(), TeamsReductions.end()) {
   }
   virtual ~CheckVarsEscapingDeclContext() = default;
   void VisitDeclStmt(const DeclStmt *S) {
public:
   void VisitStmt(const Stmt *S) {
     if (!S)
       return;
     for (const Stmt *Child : S->children())
       if (Child)
         Visit(Child);
   }
 
-  /// Returns the record that handles all the escaped local variables and used
-  /// instead of their original storage.
-  const RecordDecl *getGlobalizedRecord(bool IsInTTDRegion) {
-    if (!GlobalizedRD)
-      buildRecordForGlobalizedVars(IsInTTDRegion);
-    return GlobalizedRD;
-  }
-
-  /// Returns the field in the globalized record for the escaped variable.
-  const FieldDecl *getFieldForGlobalizedVar(const ValueDecl *VD) const {
-    assert(GlobalizedRD &&
-           "Record for globalized variables must be generated already.");
-    auto I = MappedDeclsFields.find(VD);
-    if (I == MappedDeclsFields.end())
-      return nullptr;
-    return I->getSecond();
-  }
-
   /// Returns the list of the escaped local variables/parameters.
   ArrayRef<const ValueDecl *> getEscapedDecls() const {
     return EscapedDecls.getArrayRef();
   }
 
   /// Checks if the escaped local variable is actually a parameter passed by
   /// value.
   const llvm::SmallPtrSetImpl<const Decl *> &getEscapedParameters() const {
NVPTXPrePostActionTy(
             &MappedDeclsFields)
         : Loc(Loc), GlobalizedRD(GlobalizedRD),
           MappedDeclsFields(MappedDeclsFields) {}
     void Enter(CodeGenFunction &CGF) override {
       auto &Rt =
           static_cast<CGOpenMPRuntimeGPU &>(CGF.CGM.getOpenMPRuntime());
       if (GlobalizedRD) {
         auto I = Rt.FunctionGlobalizedDecls.try_emplace(CGF.CurFn).first;
-        I->getSecond().GlobalRecord = GlobalizedRD;
         I->getSecond().MappedParams =
             std::make_unique<CodeGenFunction::OMPMapVars>();
         DeclToAddrMapTy &Data = I->getSecond().LocalVarData;
         for (const auto &Pair : MappedDeclsFields) {
           assert(Pair.getFirst()->isCanonicalDecl() &&
                  "Expected canonical declaration");
           Data.insert(std::make_pair(Pair.getFirst(),
-                                     MappedVarData(Pair.getSecond(),
-                                                   /*IsOnePerTeam=*/true)));
+                                     MappedVarData(/*IsOnePerTeam=*/true)));
         }
       }
       Rt.emitGenericVarsProlog(CGF, Loc);
     }
     void Exit(CodeGenFunction &CGF) override {
       static_cast<CGOpenMPRuntimeGPU &>(CGF.CGM.getOpenMPRuntime())
           .emitGenericVarsEpilog(CGF);
     }
if (getDataSharingMode(CGM) != CGOpenMPRuntimeGPU::Generic &&
       getExecutionMode() != CGOpenMPRuntimeGPU::EM_SPMD)
     return;
 
   CGBuilderTy &Bld = CGF.Builder;
 
   const auto I = FunctionGlobalizedDecls.find(CGF.CurFn);
   if (I == FunctionGlobalizedDecls.end())
     return;
-  if (const RecordDecl *GlobalizedVarsRecord = I->getSecond().GlobalRecord) {
-    QualType GlobalRecTy = CGM.getContext().getRecordType(GlobalizedVarsRecord);
-    QualType SecGlobalRecTy;
-
-    // Recover pointer to this function's global record. The runtime will
-    // handle the specifics of the allocation of the memory.
-    // Use actual memory size of the record including the padding
-    // for alignment purposes.
-    unsigned Alignment =
-        CGM.getContext().getTypeAlignInChars(GlobalRecTy).getQuantity();
-    unsigned GlobalRecordSize =
-        CGM.getContext().getTypeSizeInChars(GlobalRecTy).getQuantity();
-    GlobalRecordSize = llvm::alignTo(GlobalRecordSize, Alignment);
-
-    llvm::PointerType *GlobalRecPtrTy =
-        CGF.ConvertTypeForMem(GlobalRecTy)->getPointerTo();
-    llvm::Value *GlobalRecCastAddr;
-    llvm::Value *IsTTD = nullptr;
-    if (!IsInTTDRegion &&
-        (WithSPMDCheck ||
-         getExecutionMode() == CGOpenMPRuntimeGPU::EM_Unknown)) {
-      llvm::BasicBlock *ExitBB = CGF.createBasicBlock(".exit");
-      llvm::BasicBlock *SPMDBB = CGF.createBasicBlock(".spmd");
-      llvm::BasicBlock *NonSPMDBB = CGF.createBasicBlock(".non-spmd");
-      if (I->getSecond().SecondaryGlobalRecord.hasValue()) {
-        llvm::Value *RTLoc = emitUpdateLocation(CGF, Loc);
-        llvm::Value *ThreadID = getThreadID(CGF, Loc);
-        llvm::Value *PL = CGF.EmitRuntimeCall(
-            OMPBuilder.getOrCreateRuntimeFunction(CGM.getModule(),
-                                                  OMPRTL___kmpc_parallel_level),
-            {RTLoc, ThreadID});
-        IsTTD = Bld.CreateIsNull(PL);
-      }
-      llvm::Value *IsSPMD = Bld.CreateIsNotNull(
-          CGF.EmitNounwindRuntimeCall(OMPBuilder.getOrCreateRuntimeFunction(
-              CGM.getModule(), OMPRTL___kmpc_is_spmd_exec_mode)));
-      Bld.CreateCondBr(IsSPMD, SPMDBB, NonSPMDBB);
-      // There is no need to emit line number for unconditional branch.
-      (void)ApplyDebugLocation::CreateEmpty(CGF);
-      CGF.EmitBlock(SPMDBB);
-      Address RecPtr = Address(llvm::ConstantPointerNull::get(GlobalRecPtrTy),
-                               CharUnits::fromQuantity(Alignment));
-      CGF.EmitBranch(ExitBB);
-      // There is no need to emit line number for unconditional branch.
-      (void)ApplyDebugLocation::CreateEmpty(CGF);
-      CGF.EmitBlock(NonSPMDBB);
-      llvm::Value *Size = llvm::ConstantInt::get(CGM.SizeTy, GlobalRecordSize);
-      if (const RecordDecl *SecGlobalizedVarsRecord =
-              I->getSecond().SecondaryGlobalRecord.getValueOr(nullptr)) {
-        SecGlobalRecTy =
-            CGM.getContext().getRecordType(SecGlobalizedVarsRecord);
-
-        // Recover pointer to this function's global record. The runtime will
-        // handle the specifics of the allocation of the memory.
-        // Use actual memory size of the record including the padding
-        // for alignment purposes.
-        unsigned Alignment =
-            CGM.getContext().getTypeAlignInChars(SecGlobalRecTy).getQuantity();
-        unsigned GlobalRecordSize =
-            CGM.getContext().getTypeSizeInChars(SecGlobalRecTy).getQuantity();
-        GlobalRecordSize = llvm::alignTo(GlobalRecordSize, Alignment);
-        Size = Bld.CreateSelect(
-            IsTTD, llvm::ConstantInt::get(CGM.SizeTy, GlobalRecordSize), Size);
-      }
-      // TODO: allow the usage of shared memory to be controlled by
-      // the user, for now, default to global.
-      llvm::Value *GlobalRecordSizeArg[] = {
-          Size, CGF.Builder.getInt16(/*UseSharedMemory=*/0)};
-      llvm::Value *GlobalRecValue = CGF.EmitRuntimeCall(
-          OMPBuilder.getOrCreateRuntimeFunction(
-              CGM.getModule(), OMPRTL___kmpc_data_sharing_coalesced_push_stack),
-          GlobalRecordSizeArg);
-      GlobalRecCastAddr = Bld.CreatePointerBitCastOrAddrSpaceCast(
-          GlobalRecValue, GlobalRecPtrTy);
-      CGF.EmitBlock(ExitBB);
-      auto *Phi = Bld.CreatePHI(GlobalRecPtrTy,
-                                /*NumReservedValues=*/2, "_select_stack");
-      Phi->addIncoming(RecPtr.getPointer(), SPMDBB);
-      Phi->addIncoming(GlobalRecCastAddr, NonSPMDBB);
-      GlobalRecCastAddr = Phi;
-      I->getSecond().GlobalRecordAddr = Phi;
-      I->getSecond().IsInSPMDModeFlag = IsSPMD;
-    } else if (!CGM.getLangOpts().OpenMPCUDATargetParallel && IsInTTDRegion) {
-      assert(GlobalizedRecords.back().Records.size() < 2 &&
-             "Expected less than 2 globalized records: one for target and one "
-             "for teams.");
-      unsigned Offset = 0;
-      for (const RecordDecl *RD : GlobalizedRecords.back().Records) {
-        QualType RDTy = CGM.getContext().getRecordType(RD);
-        unsigned Alignment =
-            CGM.getContext().getTypeAlignInChars(RDTy).getQuantity();
-        unsigned Size = CGM.getContext().getTypeSizeInChars(RDTy).getQuantity();
-        Offset =
-            llvm::alignTo(llvm::alignTo(Offset, Alignment) + Size, Alignment);
-      }
-      unsigned Alignment =
-          CGM.getContext().getTypeAlignInChars(GlobalRecTy).getQuantity();
-      Offset = llvm::alignTo(Offset, Alignment);
-      GlobalizedRecords.back().Records.push_back(GlobalizedVarsRecord);
-      ++GlobalizedRecords.back().RegionCounter;
-      if (GlobalizedRecords.back().Records.size() == 1) {
-        assert(KernelStaticGlobalized &&
-               "Kernel static pointer must be initialized already.");
-        auto *UseSharedMemory = new llvm::GlobalVariable(
-            CGM.getModule(), CGM.Int16Ty, /*isConstant=*/true,
-            llvm::GlobalValue::InternalLinkage, nullptr,
-            "_openmp_static_kernel$is_shared");
-        UseSharedMemory->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
-        QualType Int16Ty = CGM.getContext().getIntTypeForBitwidth(
-            /*DestWidth=*/16, /*Signed=*/0);
-        llvm::Value *IsInSharedMemory = CGF.EmitLoadOfScalar(
-            Address(UseSharedMemory,
-                    CGM.getContext().getTypeAlignInChars(Int16Ty)),
-            /*Volatile=*/false, Int16Ty, Loc);
-        auto *StaticGlobalized = new llvm::GlobalVariable(
-            CGM.getModule(), CGM.Int8Ty, /*isConstant=*/false,
-            llvm::GlobalValue::CommonLinkage, nullptr);
-        auto *RecSize = new llvm::GlobalVariable(
-            CGM.getModule(), CGM.SizeTy, /*isConstant=*/true,
-            llvm::GlobalValue::InternalLinkage, nullptr,
-            "_openmp_static_kernel$size");
-        RecSize->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
-        llvm::Value *Ld = CGF.EmitLoadOfScalar(
-            Address(RecSize, CGM.getSizeAlign()), /*Volatile=*/false,
-            CGM.getContext().getSizeType(), Loc);
-        llvm::Value *ResAddr = Bld.CreatePointerBitCastOrAddrSpaceCast(
-            KernelStaticGlobalized, CGM.VoidPtrPtrTy);
-        llvm::Value *GlobalRecordSizeArg[] = {
-            llvm::ConstantInt::get(
-                CGM.Int16Ty,
-                getExecutionMode() == CGOpenMPRuntimeGPU::EM_SPMD ? 1 : 0),
-            StaticGlobalized, Ld, IsInSharedMemory, ResAddr};
-        CGF.EmitRuntimeCall(
-            OMPBuilder.getOrCreateRuntimeFunction(
-                CGM.getModule(), OMPRTL___kmpc_get_team_static_memory),
-            GlobalRecordSizeArg);
-        GlobalizedRecords.back().Buffer = StaticGlobalized;
-        GlobalizedRecords.back().RecSize = RecSize;
-        GlobalizedRecords.back().UseSharedMemory = UseSharedMemory;
-        GlobalizedRecords.back().Loc = Loc;
-      }
-      assert(KernelStaticGlobalized && "Global address must be set already.");
-      Address FrameAddr = CGF.EmitLoadOfPointer(
-          Address(KernelStaticGlobalized, CGM.getPointerAlign()),
-          CGM.getContext()
-              .getPointerType(CGM.getContext().VoidPtrTy)
-              .castAs<PointerType>());
-      llvm::Value *GlobalRecValue =
-          Bld.CreateConstInBoundsGEP(FrameAddr, Offset).getPointer();
-      I->getSecond().GlobalRecordAddr = GlobalRecValue;
-      I->getSecond().IsInSPMDModeFlag = nullptr;
-      GlobalRecCastAddr = Bld.CreatePointerBitCastOrAddrSpaceCast(
-          GlobalRecValue, CGF.ConvertTypeForMem(GlobalRecTy)->getPointerTo());
-    } else {
-      // TODO: allow the usage of shared memory to be controlled by
-      // the user, for now, default to global.
-      bool UseSharedMemory =
-          IsInTTDRegion && GlobalRecordSize <= SharedMemorySize;
-      llvm::Value *GlobalRecordSizeArg[] = {
-          llvm::ConstantInt::get(CGM.SizeTy, GlobalRecordSize),
-          CGF.Builder.getInt16(UseSharedMemory ? 1 : 0)};
-      llvm::Value *GlobalRecValue = CGF.EmitRuntimeCall(
-          OMPBuilder.getOrCreateRuntimeFunction(
-              CGM.getModule(),
-              IsInTTDRegion ? OMPRTL___kmpc_data_sharing_push_stack
-                            : OMPRTL___kmpc_data_sharing_coalesced_push_stack),
-          GlobalRecordSizeArg);
-      GlobalRecCastAddr = Bld.CreatePointerBitCastOrAddrSpaceCast(
-          GlobalRecValue, GlobalRecPtrTy);
-      I->getSecond().GlobalRecordAddr = GlobalRecValue;
-      I->getSecond().IsInSPMDModeFlag = nullptr;
-    }
-    LValue Base =
-        CGF.MakeNaturalAlignPointeeAddrLValue(GlobalRecCastAddr, GlobalRecTy);
-
-    // Emit the "global alloca" which is a GEP from the global declaration
-    // record using the pointer returned by the runtime.
-    LValue SecBase;
-    decltype(I->getSecond().LocalVarData)::const_iterator SecIt;
-    if (IsTTD) {
-      SecIt = I->getSecond().SecondaryLocalVarData->begin();
-      llvm::PointerType *SecGlobalRecPtrTy =
-          CGF.ConvertTypeForMem(SecGlobalRecTy)->getPointerTo();
-      SecBase = CGF.MakeNaturalAlignPointeeAddrLValue(
-          Bld.CreatePointerBitCastOrAddrSpaceCast(
-              I->getSecond().GlobalRecordAddr, SecGlobalRecPtrTy),
-          SecGlobalRecTy);
-    }
-    for (auto &Rec : I->getSecond().LocalVarData) {
-      bool EscapedParam = I->getSecond().EscapedParameters.count(Rec.first);
-      llvm::Value *ParValue;
-      if (EscapedParam) {
-        const auto *VD = cast<VarDecl>(Rec.first);
-        LValue ParLVal =
-            CGF.MakeAddrLValue(CGF.GetAddrOfLocalVar(VD), VD->getType());
-        ParValue = CGF.EmitLoadOfScalar(ParLVal, Loc);
-      }
-      LValue VarAddr = CGF.EmitLValueForField(Base, Rec.second.FD);
-      // Emit VarAddr basing on lane-id if required.
-      QualType VarTy;
-      if (Rec.second.IsOnePerTeam) {
-        VarTy = Rec.second.FD->getType();
-      } else {
-        llvm::Value *Ptr = CGF.Builder.CreateInBoundsGEP(
-            VarAddr.getAddress(CGF).getPointer(),
-            {Bld.getInt32(0), getNVPTXLaneID(CGF)});
-        VarTy =
-            Rec.second.FD->getType()->castAsArrayTypeUnsafe()->getElementType();
-        VarAddr = CGF.MakeAddrLValue(
-            Address(Ptr, CGM.getContext().getDeclAlign(Rec.first)), VarTy,
-            AlignmentSource::Decl);
-      }
-      Rec.second.PrivateAddr = VarAddr.getAddress(CGF);
-      if (!IsInTTDRegion &&
-          (WithSPMDCheck ||
-           getExecutionMode() == CGOpenMPRuntimeGPU::EM_Unknown)) {
-        assert(I->getSecond().IsInSPMDModeFlag &&
-               "Expected unknown execution mode or required SPMD check.");
-        if (IsTTD) {
-          assert(SecIt->second.IsOnePerTeam &&
-                 "Secondary glob data must be one per team.");
-          LValue SecVarAddr = CGF.EmitLValueForField(SecBase, SecIt->second.FD);
-          VarAddr.setAddress(
-              Address(Bld.CreateSelect(IsTTD, SecVarAddr.getPointer(CGF),
-                                       VarAddr.getPointer(CGF)),
-                      VarAddr.getAlignment()));
-          Rec.second.PrivateAddr = VarAddr.getAddress(CGF);
-        }
-        Address GlobalPtr = Rec.second.PrivateAddr;
-        Address LocalAddr = CGF.CreateMemTemp(VarTy, Rec.second.FD->getName());
-        Rec.second.PrivateAddr = Address(
-            Bld.CreateSelect(I->getSecond().IsInSPMDModeFlag,
-                             LocalAddr.getPointer(), GlobalPtr.getPointer()),
-            LocalAddr.getAlignment());
-      }
-      if (EscapedParam) {
-        const auto *VD = cast<VarDecl>(Rec.first);
-        CGF.EmitStoreOfScalar(ParValue, VarAddr);
-        I->getSecond().MappedParams->setVarAddr(CGF, VD,
-                                                VarAddr.getAddress(CGF));
-      }
-      if (IsTTD)
-        ++SecIt;
-    }
-  }
-  for (const ValueDecl *VD : I->getSecond().EscapedVariableLengthDecls) {
-    // Recover pointer to this function's global record. The runtime will
-    // handle the specifics of the allocation of the memory.
-    // Use actual memory size of the record including the padding
-    // for alignment purposes.
-    CGBuilderTy &Bld = CGF.Builder;
+
+  // Variables are marked for globalization before, based on an
+  // scape analysis.
+    const auto *VD = cast<VarDecl>(Rec.first);
+    // If it is a parameter then load the value into the Globalized memory
+    QualType VarTy = VD->getType();
+    // Get the size needed in the stack. Logic of how much to allocate
+    // and which part to give to wich thread is inside the runtime function
+    llvm::Value *Size = CGF.getTypeSize(VD->getType());
+    llvm::Value *VoidPtr = CGF.EmitRuntimeCall(
+        OMPBuilder.getOrCreateRuntimeFunction(
+            CGM.getModule(), OMPRTL___kmpc_data_sharing_push_stack),
+        {Size});
+
+    Rec.second.globalizedVal = VoidPtr;
+
+    // Let's cast the void pointer and get the address of the globalized
+    // variable
+    llvm::PointerType *VarPtrTy = CGF.ConvertTypeForMem(VarTy)->getPointerTo();
+    llvm::Value *castedVoidPtr = Bld.CreatePointerBitCastOrAddrSpaceCast(
+        VoidPtr, VarPtrTy, VD->getName() + "_on_stack");
+    LValue VarAddr = CGF.MakeNaturalAlignAddrLValue(castedVoidPtr, VarTy);
+
+    // If we are working with a parameter it is now time to get the actual value
+    // And assign it to the newly globalized location
+      I->getSecond().MappedParams->setVarAddr(CGF, VD, VarAddr.getAddress(CGF));
+  for (auto &VD : I->getSecond().EscapedVariableLengthDecls) {
+    // If it is a parameter then load the value into the Globalized memory
+    // QualType VarTy = VD->getType();
+    // Get the size needed in the stack. Logic of how much to allocate
+    // and which part to give to wich thread is inside the runtime function
     llvm::Value *Size = CGF.getTypeSize(VD->getType());
     CharUnits Align = CGM.getContext().getDeclAlign(VD);
     Size = Bld.CreateNUWAdd(
         Size, llvm::ConstantInt::get(CGF.SizeTy, Align.getQuantity() - 1));
     llvm::Value *AlignVal =
         llvm::ConstantInt::get(CGF.SizeTy, Align.getQuantity());
     Size = Bld.CreateUDiv(Size, AlignVal);
     Size = Bld.CreateNUWMul(Size, AlignVal);
-    // TODO: allow the usage of shared memory to be controlled by
-    // the user, for now, default to global.
-    llvm::Value *GlobalRecordSizeArg[] = {
-        Size, CGF.Builder.getInt16(/*UseSharedMemory=*/0)};
-    llvm::Value *GlobalRecValue = CGF.EmitRuntimeCall(
+    llvm::Value *VoidPtr = CGF.EmitRuntimeCall(
         OMPBuilder.getOrCreateRuntimeFunction(
-            CGM.getModule(), OMPRTL___kmpc_data_sharing_coalesced_push_stack),
-        GlobalRecordSizeArg);
-    llvm::Value *GlobalRecCastAddr = Bld.CreatePointerBitCastOrAddrSpaceCast(
-        GlobalRecValue, CGF.ConvertTypeForMem(VD->getType())->getPointerTo());
-    LValue Base = CGF.MakeAddrLValue(GlobalRecCastAddr, VD->getType(),
+            CGM.getModule(), OMPRTL___kmpc_data_sharing_push_stack),
+        {Size});
+
+    I->getSecond().EscapedVariableLengthDeclsAddrs.emplace_back(VoidPtr);
+    LValue Base = CGF.MakeAddrLValue(VoidPtr, VD->getType(),
                                      CGM.getContext().getDeclAlign(VD),
                                      AlignmentSource::Decl);
     I->getSecond().MappedParams->setVarAddr(CGF, cast<VarDecl>(VD),
                                             Base.getAddress(CGF));
-    I->getSecond().EscapedVariableLengthDeclsAddrs.emplace_back(GlobalRecValue);
   }
   I->getSecond().MappedParams->apply(CGF);
 }
 
 void CGOpenMPRuntimeGPU::emitGenericVarsEpilog(CodeGenFunction &CGF,
                                                  bool WithSPMDCheck) {
   if (getDataSharingMode(CGM) != CGOpenMPRuntimeGPU::Generic &&
       getExecutionMode() != CGOpenMPRuntimeGPU::EM_SPMD)
     return;
 
   const auto I = FunctionGlobalizedDecls.find(CGF.CurFn);
   if (I != FunctionGlobalizedDecls.end()) {
-    I->getSecond().MappedParams->restore(CGF);
-    if (!CGF.HaveInsertPoint())
-      return;
     for (llvm::Value *Addr :
          llvm::reverse(I->getSecond().EscapedVariableLengthDeclsAddrs)) {
       CGF.EmitRuntimeCall(
           OMPBuilder.getOrCreateRuntimeFunction(
               CGM.getModule(), OMPRTL___kmpc_data_sharing_pop_stack),
           Addr);
     }
-    if (I->getSecond().GlobalRecordAddr) {
-      if (!IsInTTDRegion &&
-          (WithSPMDCheck ||
-           getExecutionMode() == CGOpenMPRuntimeGPU::EM_Unknown)) {
-        CGBuilderTy &Bld = CGF.Builder;
-        llvm::BasicBlock *ExitBB = CGF.createBasicBlock(".exit");
-        llvm::BasicBlock *NonSPMDBB = CGF.createBasicBlock(".non-spmd");
-        Bld.CreateCondBr(I->getSecond().IsInSPMDModeFlag, ExitBB, NonSPMDBB);
-        // There is no need to emit line number for unconditional branch.
-        (void)ApplyDebugLocation::CreateEmpty(CGF);
-        CGF.EmitBlock(NonSPMDBB);
-        CGF.EmitRuntimeCall(
-            OMPBuilder.getOrCreateRuntimeFunction(
-                CGM.getModule(), OMPRTL___kmpc_data_sharing_pop_stack),
-            CGF.EmitCastToVoidPtr(I->getSecond().GlobalRecordAddr));
-        CGF.EmitBlock(ExitBB);
-      } else if (!CGM.getLangOpts().OpenMPCUDATargetParallel && IsInTTDRegion) {
-        assert(GlobalizedRecords.back().RegionCounter > 0 &&
-               "region counter must be > 0.");
-        --GlobalizedRecords.back().RegionCounter;
-        // Emit the restore function only in the target region.
-        if (GlobalizedRecords.back().RegionCounter == 0) {
-          QualType Int16Ty = CGM.getContext().getIntTypeForBitwidth(
-              /*DestWidth=*/16, /*Signed=*/0);
-          llvm::Value *IsInSharedMemory = CGF.EmitLoadOfScalar(
-              Address(GlobalizedRecords.back().UseSharedMemory,
-                      CGM.getContext().getTypeAlignInChars(Int16Ty)),
-              /*Volatile=*/false, Int16Ty, GlobalizedRecords.back().Loc);
-          llvm::Value *Args[] = {
-              llvm::ConstantInt::get(
-                  CGM.Int16Ty,
-                  getExecutionMode() == CGOpenMPRuntimeGPU::EM_SPMD ? 1 : 0),
-              IsInSharedMemory};
-          CGF.EmitRuntimeCall(
-              OMPBuilder.getOrCreateRuntimeFunction(
-                  CGM.getModule(), OMPRTL___kmpc_restore_team_static_memory),
-              Args);
-        }
-      } else {
-        CGF.EmitRuntimeCall(
-            OMPBuilder.getOrCreateRuntimeFunction(
-                CGM.getModule(), OMPRTL___kmpc_data_sharing_pop_stack),
-            I->getSecond().GlobalRecordAddr);
-      }
+    for (auto &Rec : llvm::reverse(I->getSecond().LocalVarData)) {
+      I->getSecond().MappedParams->restore(CGF);
+      // const auto *VD = cast<VarDecl>(Rec.first);
+
+      // Get the size needed in the stack. Logic of how much to allocate
+      // and which part to give to wich thread is inside the runtime function
+      // llvm::Value *size = CGF.getTypeSize(VD->getType());
+          {Rec.second.globalizedVal});
     }
   }
 }
 
 void CGOpenMPRuntimeGPU::emitTeamsCall(CodeGenFunction &CGF,
                                          const OMPExecutableDirective &D,
                                          SourceLocation Loc,
                                          llvm::Function *OutlinedFn,
if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
     if (NeedToDelayGlobalization &&
         getExecutionMode() == CGOpenMPRuntimeGPU::EM_SPMD)
       return;
   }
   if (!Body)
     return;
   CheckVarsEscapingDeclContext VarChecker(CGF, TeamAndReductions.second);
   VarChecker.Visit(Body);
-  const RecordDecl *GlobalizedVarsRecord =
-      VarChecker.getGlobalizedRecord(IsInTTDRegion);
   TeamAndReductions.first = nullptr;
   TeamAndReductions.second.clear();
   ArrayRef<const ValueDecl *> EscapedVariableLengthDecls =
       VarChecker.getEscapedVariableLengthDecls();
-  if (!GlobalizedVarsRecord && EscapedVariableLengthDecls.empty())
-    return;
   auto I = FunctionGlobalizedDecls.try_emplace(CGF.CurFn).first;
   I->getSecond().MappedParams =
       std::make_unique<CodeGenFunction::OMPMapVars>();
-  I->getSecond().GlobalRecord = GlobalizedVarsRecord;
   I->getSecond().EscapedParameters.insert(
       VarChecker.getEscapedParameters().begin(),
       VarChecker.getEscapedParameters().end());
   I->getSecond().EscapedVariableLengthDecls.append(
       EscapedVariableLengthDecls.begin(), EscapedVariableLengthDecls.end());
   DeclToAddrMapTy &Data = I->getSecond().LocalVarData;
   for (const ValueDecl *VD : VarChecker.getEscapedDecls()) {
     assert(VD->isCanonicalDecl() && "Expected canonical declaration");
-    const FieldDecl *FD = VarChecker.getFieldForGlobalizedVar(VD);
-    Data.insert(std::make_pair(VD, MappedVarData(FD, IsInTTDRegion)));
-  }
-  if (!IsInTTDRegion && !NeedToDelayGlobalization && !IsInParallelRegion) {
-    CheckVarsEscapingDeclContext VarChecker(CGF, llvm::None);
-    VarChecker.Visit(Body);
-    I->getSecond().SecondaryGlobalRecord =
-        VarChecker.getGlobalizedRecord(/*IsInTTDRegion=*/true);
-    I->getSecond().SecondaryLocalVarData.emplace();
-    DeclToAddrMapTy &Data = I->getSecond().SecondaryLocalVarData.getValue();
-    for (const ValueDecl *VD : VarChecker.getEscapedDecls()) {
-      assert(VD->isCanonicalDecl() && "Expected canonical declaration");
-      const FieldDecl *FD = VarChecker.getFieldForGlobalizedVar(VD);
-      Data.insert(
-          std::make_pair(VD, MappedVarData(FD, /*IsInTTDRegion=*/true)));
-    }
+    Data.insert(std::make_pair(VD, MappedVarData(IsInTTDRegion)));
   }
+
   if (!NeedToDelayGlobalization) {
     emitGenericVarsProlog(CGF, D->getBeginLoc(), /*WithSPMDCheck=*/true);
     struct GlobalizationScope final : EHScopeStack::Cleanup {
       GlobalizationScope() = default;
 
       void Emit(CodeGenFunction &CGF, Flags flags) override {
         static_cast<CGOpenMPRuntimeGPU &>(CGF.CGM.getOpenMPRuntime())
             .emitGenericVarsEpilog(CGF, /*WithSPMDCheck=*/true);

llvm/include/llvm/Frontend/OpenMP/OMPKinds.def

__OMP_RTL(__kmpc_nvptx_teams_reduce_nowait_v2, false, Int32, IdentPtr, Int32,
           VoidPtr, Int32, VoidPtr, ShuffleReducePtr, InterWarpCopyPtr,
           GlobalListPtr, GlobalListPtr, GlobalListPtr, GlobalListPtr)
 
 __OMP_RTL(__kmpc_shuffle_int64, false, Int64, Int64, Int16, Int16)
 __OMP_RTL(__kmpc_data_sharing_init_stack, false, Void, )
 __OMP_RTL(__kmpc_data_sharing_init_stack_spmd, false, Void, )
 
 __OMP_RTL(__kmpc_data_sharing_coalesced_push_stack, false, VoidPtr, SizeTy, Int16)
-__OMP_RTL(__kmpc_data_sharing_push_stack, false, VoidPtr, SizeTy, Int16)
+__OMP_RTL(__kmpc_data_sharing_push_stack, false, VoidPtr, SizeTy)
 __OMP_RTL(__kmpc_data_sharing_pop_stack, false, Void, VoidPtr)
 __OMP_RTL(__kmpc_begin_sharing_variables, false, Void, VoidPtrPtrPtr, SizeTy)
 __OMP_RTL(__kmpc_end_sharing_variables, false, Void, )
 __OMP_RTL(__kmpc_get_shared_variables, false, Void, VoidPtrPtrPtr)
 __OMP_RTL(__kmpc_parallel_level, false, Int16, IdentPtr, Int32)
 __OMP_RTL(__kmpc_is_spmd_exec_mode, false, Int8, )
 __OMP_RTL(__kmpc_get_team_static_memory, false, Void, Int16, VoidPtr, SizeTy,
           Int16, VoidPtrPtr)

openmp/libomptarget/deviceRTLs/common/src/data_sharing.cu

EXTERN void *__kmpc_data_sharing_coalesced_push_stack(size_t DataSize,
                                                       int16_t UseSharedMemory) {
   return data_sharing_push_stack_common(DataSize);
 }
 
 // Called at the time of the kernel initialization. This is used to initilize
 // the list of references to shared variables and to pre-allocate global storage
 // for holding the globalized variables.
 //
-// By default the globalized variables are stored in global memory. If the
-// UseSharedMemory is set to true, the runtime will attempt to use shared memory
-// as long as the size requested fits the pre-allocated size.
-EXTERN void *__kmpc_data_sharing_push_stack(size_t DataSize,
-                                            int16_t UseSharedMemory) {
+EXTERN void *__kmpc_data_sharing_push_stack(size_t DataSize) {
   // Compute the total memory footprint of the requested data.
   // The master thread requires a stack only for itself. A worker
   // thread (which at this point is a warp master) will require
   // space for the variables of each thread in the warp,
   // i.e. one DataSize chunk per warp lane.
   // TODO: change WARPSIZE to the number of active threads in the warp.
   size_t PushSize = (isRuntimeUninitialized() || IsMasterThread(isSPMDMode()))
                         ? DataSize

openmp/libomptarget/deviceRTLs/interface.h

 typedef enum omp_proc_bind_t {
   omp_proc_bind_false = 0,
   omp_proc_bind_true = 1,
   omp_proc_bind_master = 2,
   omp_proc_bind_close = 3,
   omp_proc_bind_spread = 4
 } omp_proc_bind_t;
 
 EXTERN double omp_get_wtick(void);
 EXTERN double omp_get_wtime(void);
 
 EXTERN void omp_set_num_threads(int num);
 EXTERN int omp_get_num_threads(void);
 EXTERN int omp_get_max_threads(void);
 EXTERN int omp_get_thread_limit(void);
 EXTERN int omp_get_thread_num(void);
 EXTERN int omp_get_num_procs(void);
 EXTERN int omp_in_parallel(void);
 EXTERN int omp_in_final(void);
 EXTERN void omp_set_dynamic(int flag);
 EXTERN int omp_get_dynamic(void);
 EXTERN void omp_set_nested(int flag);
 EXTERN int omp_get_nested(void);
 EXTERN void omp_set_max_active_levels(int level);
 EXTERN int omp_get_max_active_levels(void);
 EXTERN int omp_get_level(void);
 EXTERN int omp_get_active_level(void);
 EXTERN int omp_get_ancestor_thread_num(int level);
 EXTERN int omp_get_team_size(int level);
 
 EXTERN void omp_init_lock(omp_lock_t *lock);
 EXTERN void omp_init_nest_lock(omp_nest_lock_t *lock);
 EXTERN void omp_destroy_lock(omp_lock_t *lock);
 EXTERN void omp_destroy_nest_lock(omp_nest_lock_t *lock);
 EXTERN void omp_set_lock(omp_lock_t *lock);
 EXTERN void omp_set_nest_lock(omp_nest_lock_t *lock);

 EXTERN void __kmpc_kernel_prepare_parallel(void *WorkFn);
 EXTERN bool __kmpc_kernel_parallel(void **WorkFn);
 EXTERN void __kmpc_kernel_end_parallel();
 
 EXTERN void __kmpc_data_sharing_init_stack();
 EXTERN void __kmpc_data_sharing_init_stack_spmd();
 EXTERN void *__kmpc_data_sharing_coalesced_push_stack(size_t size,
     int16_t UseSharedMemory);
-EXTERN void *__kmpc_data_sharing_push_stack(size_t size, int16_t UseSharedMemory);
+EXTERN void *__kmpc_data_sharing_push_stack(size_t size);
 EXTERN void __kmpc_data_sharing_pop_stack(void *a);
 EXTERN void __kmpc_begin_sharing_variables(void ***GlobalArgs, size_t nArgs);
 EXTERN void __kmpc_end_sharing_variables();
 EXTERN void __kmpc_get_shared_variables(void ***GlobalArgs);
 
 // The slot used for data sharing by the master and worker threads. We use a
 // complete (default size version and an incomplete one so that we allow sizes
 // greater than the default).